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1

Phylum Tardigrada  

NSDL National Science Digital Library

This "Online Zoologists" web page features a technical description of the phylum Tardigrada. Written in an outline format, the page includes a definition of the phylum and discusses external features, internal features, reproduction, embryology, ecology and physiology, classification, phylogeny, and references.

Elsberry, Wesley R.

2009-07-01

2

Gregarine parasitism in dragonfly populations of Central Texas with an assessment of fitness costs in Erythemis simplicicollis.  

E-print Network

??Dragonfly parasites are widespread and frequently include gregarines (Phylum Apicomplexa) in the gut of the host. Gregarines are ubiquitous protozoan parasites that infect arthropods worldwide.… (more)

Locklin, Jason L.

2010-01-01

3

Lateral Gene Transfer of Family A DNA Polymerases between Thermophilic Viruses, Aquificae, and Apicomplexa  

PubMed Central

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

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

2013-01-01

4

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

PubMed

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

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

2010-05-01

5

Foodborne protozoan parasites  

Microsoft Academic Search

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

David Dawson

2005-01-01

6

Babesia divergens (Phylum Apicomplexa) in vitro growth in the presence of calf serum  

Microsoft Academic Search

Resistance to severe babesiosis in young calves has frequently been ascribed to an unknown serum factor(s) which inhibits growth of Babesia bovis in vitro. Our experiments show that young calf sera are as suitable as adult bovine sera for the in vitro culture of Babesia divergens, indicating that in this species at least inverse age resistance is due to alternative

A Zintl; H. E Skerrett; J. S Gray; P. O Brophy; G Mulcahy

2004-01-01

7

Effects of Artemisia annua and Foeniculum vulgare on chickens highly infected with Eimeria tenella (Phylum Apicomplexa)  

PubMed Central

Background Intensive poultry production systems depend on chemoprophylaxis with anticoccidial drugs to combat infection. A floor-pen study was conducted to evaluate the anticoccidial effect of Artemisia annua and Foeniculum vulgare on Eimeria tenella infection. Five experimental groups were established: negative control (untreated, unchallenged); positive control (untreated, challenged); a group medicated with 125 ppm lasalocid and challenged; a group medicated with A. annua leaf powder at 1.5% in feed and challenged; and a group treated with the mixed oils of A. annua and Foeniculum vulgare in equal parts, 7.5% in water and challenged. The effects of A. annua and oil extract of A. annua + F. vulgare on E. tenella infection were assessed by clinical signs, mortality, fecal oocyst output, faeces, lesion score, weight gain, and feed conversion. Results Clinical signs were noticed only in three chickens from the lasalocid group, six from the A. annua group, and nine from the A. annua?+?F. vulgare group, but were present in 19 infected chickens from the positive control group. Bloody diarrhea was registered in only two chickens from A. annua group, but in 17 chickens from the positive control group. Mortality also occurred in the positive control group (7/20). Chickens treated with A. annua had a significant reduction in faecal oocysts (95.6%; P?=?0.027) and in lesion score (56.3%; P?=?0.005) when compared to the positive control. At the end of experiment, chickens treated with A. annua leaf powder had the highest body weight gain (68.2 g/day), after the negative control group, and the best feed conversion (1.85) among all experimental groups. Conclusions Our results suggest that A. annua leaf powder (Aa-p), at 1.5% of the daily diet post-infection, can be a valuable alternative for synthetic coccidiostats, such as lasalocid. PMID:24731599

2014-01-01

8

The genus atoxoplasma (Protozoa, Apicomplexa).  

PubMed

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

Levine, N D

1982-08-01

9

Waterborne protozoan pathogens.  

PubMed Central

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

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

1997-01-01

10

DNA barcoding identifies Eimeria species and contributes to the phylogenetics of coccidian parasites (Eimeriorina, Apicomplexa, Alveolata).  

PubMed

Partial (? 780 bp) mitochondrial cytochrome c oxidase subunit I (COI) and near complete nuclear 18S rDNA (? 1,780 bp) sequences were directly compared to assess their relative usefulness as markers for species identification and phylogenetic analysis of coccidian parasites (phylum Apicomplexa). Fifteen new COI partial sequences were obtained using two pairs of new primers from rigorously characterised (sensu Reid and Long, 1979) laboratory strains of seven Eimeria spp. infecting chickens as well as three additional sequences from cloned laboratory strains of Toxoplasma gondii (ME49 and GT1) and Neospora caninum (NC1) that were used as outgroup taxa for phylogenetic analyses. Phylogenetic analyses based on COI sequences yielded robust support for the monophyly of individual Eimeria spp. infecting poultry except for the Eimeria mitis/mivati clade; however, the lack of a phenotypically characterised strain of E. mivati precludes drawing any firm conclusions regarding this observation. Unlike in the 18S rDNA-based phylogenetic reconstructions, Eimerianecatrix and Eimeria tenella formed monophyletic clades based on partial COI sequences. A species delimitation test was performed to determine the probability of making a correct identification of an unknown specimen (sequence) based on either complete 18S rDNA or partial COI sequences; in almost all cases, the partial COI sequences were more reliable as species-specific markers than complete 18S rDNA sequences. These observations demonstrate that partial COI sequences provide more synapomorphic characters at the species level than complete 18S rDNA sequences from the same taxa. We conclude that COI performs well as a marker for the identification of coccidian taxa (Eimeriorina) and will make an excellent DNA 'barcode' target for coccidia. The COI locus, in combination with an 18S rDNA sequence as an 'anchor', has sufficient phylogenetic signal to assist in the resolution of apparent paraphylies within the coccidia and likely more broadly within the Apicomplexa. PMID:21515277

Ogedengbe, Joseph D; Hanner, Robert H; Barta, John R

2011-07-01

11

Photoacoustic spectroscopy of man infecting protozoans  

NASA Astrophysics Data System (ADS)

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.

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

1998-08-01

12

Photoacoustic spectroscopy of man infecting protozoans  

SciTech Connect

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.

Acosta-Avalos, D. [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, Barrio da Urca, CEP 22290-180, Rio de Janeiro (Brazil); Alvarado-Gil, J. J. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Apartado Postal 73 Cordemex, Merida, Yucatan, 97310 (Mexico); Vargas, H. [Universidade Estadual do Norte Fluminense, CEP 28015-620, Rio de Janeiro (Brazil)

1998-08-28

13

Molecular determinants archetypical to the phylum Nematoda  

PubMed Central

Background Nematoda diverged from other animals between 600–1,200 million years ago and has become one of the most diverse animal phyla on earth. Most nematodes are free-living animals, but many are parasites of plants and animals including humans, posing major ecological and economical challenges around the world. Results We investigated phylum-specific molecular characteristics in Nematoda by exploring over 214,000 polypeptides from 32 nematode species including 27 parasites. Over 50,000 nematode protein families were identified based on primary sequence, including ~10% with members from at least three different species. Nearly 1,600 of the multi-species families did not share homology to Pfam domains, including a total of 758 restricted to Nematoda. Majority of the 462 families that were conserved among both free-living and parasitic species contained members from multiple nematode clades, yet ~90% of the 296 parasite-specific families originated only from a single clade. Features of these protein families were revealed through extrapolation of essential functions from observed RNAi phenotypes in C. elegans, bioinformatics-based functional annotations, identification of distant homology based on protein folds, and prediction of expression at accessible nematode surfaces. In addition, we identified a group of nematode-restricted sequence features in energy-generating electron transfer complexes as potential targets for new chemicals with minimal or no toxicity to the host. Conclusion This study identified and characterized the molecular determinants that help in defining the phylum Nematoda, and therefore improved our understanding of nematode protein evolution and provided novel insights for the development of next generation parasite control strategies. PMID:19296854

2009-01-01

14

Interferon effects on protozoan infections  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

15

Deuterostome phylogeny reveals monophyletic chordates and the new phylum Xenoturbellida  

E-print Network

LETTERS Deuterostome phylogeny reveals monophyletic chordates and the new phylum Xenoturbellida vertebrates, the related invertebrate chordates (tunicates and cephalochordates) and three other inver studies of chordate classes and a sea urchin have indicated that urochordates might be the closest inverte

Kirschner, Marc W.

16

Culturing and Using Protozoans in the Laboratory.  

ERIC Educational Resources Information Center

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)

Hummer, Paul J., Jr.

1993-01-01

17

Description of 'Synergistetes' phyl. nov. and emended description of the phylum 'Deferribacteres' and of the family Syntrophomonadaceae, phylum 'Firmicutes'.  

PubMed

The number of bacterial phyla has greatly increased in the past decade. Among them, a candidate division named 'Synergistes' was proposed in a phylogenetic study on the global diversity of bacteria. We previously described the genus Jonquetella and suggested that it belonged to this not yet well-delineated candidate phylum. 16S rRNA gene based-phylogeny studies were conducted using four reconstruction methods and 599 sequences forming five datasets were used in an alternative treeing approach. These analyses indicated that the genera Aminiphilus, Aminobacterium, Aminomonas, Anaerobaculum, Dethiosulfovibrio, Jonquetella, Synergistes, Thermanaerovibrio and Thermovirga should be grouped in the same high-level taxon. This taxon was shown to be a phylum-rank lineage in the domain Bacteria and, because of the prior use of the name Synergistes for a genus, the name 'Synergistetes' is proposed for this candidate phylum. We also propose an emended delineation of the phylum 'Deferribacteres', which is now only represented by the family Deferribacteriaceae. The emended family Syntrophomonadaceae is limited to the genera Pelospora, Syntrophomonas, Syntrophothermus and Thermosyntropha. PMID:19406787

Jumas-Bilak, Estelle; Roudière, Laurent; Marchandin, Hélène

2009-05-01

18

Intestinal Protozoans in Adults with Diarrhea  

PubMed Central

Background: Diarrhea is one of the most common presenting complaints in human immunodeficiency virus-infected individuals. Aims: The study was designed to determine the magnitude of opportunistic and nonopportunistic intestinal parasitic infections among diarrheal patients and association between CD4+ T-cell counts and human immunodeficiency virus (HIV)-infected intestinal parasites. Materials and Methods: A cross-sectional study was conducted among 207 enrolled diarrheal patients attending HIV integrated counseling and testing center from January 2012 to December 2012. Stool samples were subjected to special modified Ziehl-Neelsen and chromotrope staining method for detection of opportunistic protozoans. Blood samples were also collected from all study subjects for HIV testing and CD4+ T-cell counts were estimated by only in HIV-infected patients. Results: Intestinal parasitic pathogens were detected in 46.1% HIV-infected patients and the major pathogens were opportunistic protozoans 32.2% (37/115), most common being Isospora belli 16.5% (19/115) followed by Cryptosporidium parvum 12.2% (14/115). In HIV noninfected diarrheal patients, major pathogens detected were Entamoeba histolytica/Entamoeba dispar 8.7% (8/92) and Ascaris lumbricoides 3.3% (3/92). Conclusions: The opportunistic intestinal protozoans especially I. belli and C. parvum were most commonly isolated in HIV-infected patients with diarrhea. Majority of the infections occurred in patients when a CD4+ T-cell counts were less than 200 cells/?l. PMID:24404554

Dash, Muktikesh; Padhi, Sanghamitra; Panda, Pritilata; Parida, Banojini

2013-01-01

19

An Expanded Genomic Representation of the Phylum Cyanobacteria  

PubMed Central

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

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

20

Barcoding of arrow worms (Phylum Chaetognatha) from three oceans: genetic diversity and evolution within an enigmatic phylum.  

PubMed

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 all ocean basins, while others present disjunct ranges, in some cases with the same species apparently found at both poles. To better understand how these complex evolutionary and geographic variables are reflected in the species makeup of chaetognaths, we analyze DNA barcodes of the mitochondrial cytochrome oxidase c subunit I (COI) gene, from 52 specimens of 14 species of chaetognaths collected mainly from the Atlantic Ocean. Barcoding analysis was highly successful at discriminating described species of chaetognaths across the phylum, and revealed little geographical structure. This barcode analysis reveals hitherto unseen genetic variation among species of arrow worms, and provides insight into some species relationships of this enigmatic group. PMID:20376348

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

2010-01-01

21

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

PubMed Central

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 all ocean basins, while others present disjunct ranges, in some cases with the same species apparently found at both poles. To better understand how these complex evolutionary and geographic variables are reflected in the species makeup of chaetognaths, we analyze DNA barcodes of the mitochondrial cytochrome oxidase c subunit I (COI) gene, from 52 specimens of 14 species of chaetognaths collected mainly from the Atlantic Ocean. Barcoding analysis was highly successful at discriminating described species of chaetognaths across the phylum, and revealed little geographical structure. This barcode analysis reveals hitherto unseen genetic variation among species of arrow worms, and provides insight into some species relationships of this enigmatic group. PMID:20376348

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

2010-01-01

22

OYSTER SERUM AGGLUTININS AND RESISTANCE TO PROTOZOAN PARASITES  

EPA Science Inventory

Serum agglutinins or lectins are reported to be induced in marine molluscs by exposure to bacteria and may enhance bacterial clearance from the host; however, there is a little information on possible relationships between lectins and protozoan parasites of molluscs. wo protozoan...

23

Chordate evolution and the three-phylum system.  

PubMed

Traditional metazoan phylogeny classifies the Vertebrata as a subphylum of the phylum Chordata, together with two other subphyla, the Urochordata (Tunicata) and the Cephalochordata. The Chordata, together with the phyla Echinodermata and Hemichordata, comprise a major group, the Deuterostomia. Chordates invariably possess a notochord and a dorsal neural tube. Although the origin and evolution of chordates has been studied for more than a century, few authors have intimately discussed taxonomic ranking of the three chordate groups themselves. Accumulating evidence shows that echinoderms and hemichordates form a clade (the Ambulacraria), and that within the Chordata, cephalochordates diverged first, with tunicates and vertebrates forming a sister group. Chordates share tadpole-type larvae containing a notochord and hollow nerve cord, whereas ambulacrarians have dipleurula-type larvae containing a hydrocoel. We propose that an evolutionary occurrence of tadpole-type larvae is fundamental to understanding mechanisms of chordate origin. Protostomes have now been reclassified into two major taxa, the Ecdysozoa and Lophotrochozoa, whose developmental pathways are characterized by ecdysis and trochophore larvae, respectively. Consistent with this classification, the profound dipleurula versus tadpole larval differences merit a category higher than the phylum. Thus, it is recommended that the Ecdysozoa, Lophotrochozoa, Ambulacraria and Chordata be classified at the superphylum level, with the Chordata further subdivided into three phyla, on the basis of their distinctive characteristics. PMID:25232138

Satoh, Noriyuki; Rokhsar, Daniel; Nishikawa, Teruaki

2014-11-01

24

Chordate evolution and the three-phylum system  

PubMed Central

Traditional metazoan phylogeny classifies the Vertebrata as a subphylum of the phylum Chordata, together with two other subphyla, the Urochordata (Tunicata) and the Cephalochordata. The Chordata, together with the phyla Echinodermata and Hemichordata, comprise a major group, the Deuterostomia. Chordates invariably possess a notochord and a dorsal neural tube. Although the origin and evolution of chordates has been studied for more than a century, few authors have intimately discussed taxonomic ranking of the three chordate groups themselves. Accumulating evidence shows that echinoderms and hemichordates form a clade (the Ambulacraria), and that within the Chordata, cephalochordates diverged first, with tunicates and vertebrates forming a sister group. Chordates share tadpole-type larvae containing a notochord and hollow nerve cord, whereas ambulacrarians have dipleurula-type larvae containing a hydrocoel. We propose that an evolutionary occurrence of tadpole-type larvae is fundamental to understanding mechanisms of chordate origin. Protostomes have now been reclassified into two major taxa, the Ecdysozoa and Lophotrochozoa, whose developmental pathways are characterized by ecdysis and trochophore larvae, respectively. Consistent with this classification, the profound dipleurula versus tadpole larval differences merit a category higher than the phylum. Thus, it is recommended that the Ecdysozoa, Lophotrochozoa, Ambulacraria and Chordata be classified at the superphylum level, with the Chordata further subdivided into three phyla, on the basis of their distinctive characteristics. PMID:25232138

Satoh, Noriyuki; Rokhsar, Daniel; Nishikawa, Teruaki

2014-01-01

25

Drug repurposing and human parasitic protozoan diseases.  

PubMed

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

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

2014-08-01

26

Kinetoplastids: related protozoan pathogens, different diseases  

PubMed Central

Kinetoplastids are a group of flagellated protozoans that include the species Trypanosoma and Leishmania, which are human pathogens with devastating health and economic effects. The sequencing of the genomes of some of these species has highlighted their genetic relatedness and underlined differences in the diseases that they cause. As we discuss in this Review, steady progress using a combination of molecular, genetic, immunologic, and clinical approaches has substantially increased understanding of these pathogens and important aspects of the diseases that they cause. Consequently, the paths for developing additional measures to control these “neglected diseases” are becoming increasingly clear, and we believe that the opportunities for developing the drugs, diagnostics, vaccines, and other tools necessary to expand the armamentarium to combat these diseases have never been better. PMID:18382742

Stuart, Ken; Brun, Reto; Croft, Simon; Fairlamb, Alan; Gurtler, Ricardo E.; McKerrow, Jim; Reed, Steve; Tarleton, Rick

2008-01-01

27

Approaches to protozoan drug discovery: phenotypic screening.  

PubMed

Determining the activity of a compound and the potential impact on a diseased state is frequently undertaken using phenotypic or target-based approaches. Phenotypic screens have the advantage of the whole organism being exposed to the compound and thus all the targets and biological pathways associated with it. Cell penetration and access to targets in their "natural" environment are taken into account. Unless utilizing a genetically modified organism with an additional target associated indicator, elucidation of specific target(s) of active compounds is necessary. Target discovery is desirable to allow development of chemical entities based upon knowledge of the target structure. Phenotypic drug discovery has successfully identified new molecular entities for neglected protozoan disease research. In this perspective, the phenotypic approaches used to identify chemical entities for drug discovery and for use as tools against the parasites Plasmodium falciparum, Trypanosoma brucei brucei, and Trypanosoma cruzi will be outlined. PMID:23927763

Sykes, Melissa L; Avery, Vicky M

2013-10-24

28

Drug repurposing and human parasitic protozoan diseases  

PubMed Central

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

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

2014-01-01

29

Lateral Gene Transfer of Family A DNA Polymerases between Thermophilic Viruses, Aquificae, and Apicomplexa  

E-print Network

the informational content of genomes was a critical step in the transformation from an abiotic to a biotic world of a variety of otherwise unrelated Bacteria, each of which additionally encoded a prototypical bacterial Pol may have functions associated with diversity-generating recombination in both Bacteria and Apicomplexa

Ahmad, Sajjad

30

Diversity and Habitat Niche Modeling of Candidate Archaeal Phylum Aigarchaeota  

NASA Astrophysics Data System (ADS)

';Aigarchaeota' (formerly known as pSL4 and Hot Water Crenarchaeotic Group I (HWCGI)) is a candidate phylum of Archaea known only by 16S rRNA gene fragments from cultivation-independent microbial surveys and a single composite genome from Candidatus ';Caldiarchaeum subterraneum', an inhabitant of a subterranean gold mine in Japan. Sequences reported in various publications are found exclusively in geothermal settings, but a comprehensive assessment has not yet been performed. We mined public databases for 16S rRNA gene sequences related to known ';Aigarchaeota' and used a combination of approaches to rigorously define the phylogenetic boundaries of the phylum. The analyses supported the proposed relationship between ';Aigarchaeota', Thaumarchaeota, Crenarchaeota, and Korarchaeota in the so-called 'TACK superphylum' and identified ~200 16S rRNA genes and gene fragments belonging to ';Aigarchaeota', including those recovered from terrestrial geothermal systems on several continents (North America, Asia, Africa, Europe, and Oceania) and marine geothermal and subsurface samples in both the Atlantic and Pacific. ';Aigarchaeota' belonged to at least three family- to order-level groups and at least seven genus-level groups. All genus-level groups were recovered from geographically distant locations, suggesting a global distribution within amenable habitats. ';Aigarchaeota'-specific primers for the polymerase chain reaction (PCR) amplification of 16S rRNA genes were designed using SP-Designer and reviewed using the Ribosomal Database Project Probe Match tool. The primers will be used to determine the presence and abundance of ';Aigarchaeota' in a wide variety of samples from terrestrial geothermal systems in the western U.S. and Asia. These phylogenetic data, along with a large geochemical database, will be analyzed using multivariate statistics to develop biogeographic and habitat niche models for ';Aigarchaeota'. This study offers the first coherent view of the distribution and diversity of the ';Aigarchaeota' and lays the groundwork for further inquiry into how environmental factors might control the presence and abundance of this candidate phylum in geothermal environments.

Alba, T. W.; Goertz, G.; Williams, A. J.; Cole, J. K.; Murugapiran, S. K.; Dodsworth, J. A.; Hedlund, B. P.

2013-12-01

31

Invasion and Intracellular Survival by Protozoan Parasites  

PubMed Central

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

Sibley, L. David

2013-01-01

32

Protozoan infections of the gastrointestinal tract.  

PubMed

The review provides current views on human protozoan parasites of the gut. The recognition of the importance of cryptosporidium, cyclospora and microsporidia over the last three decades emphasises the possibility that more pathogenic intestinal protozoa are presently unrecognized. Each of these is a zoonotic infection and the potential for a zoonotic element to the transmission of giardiasis has been recognized. A common theme in increased understanding of the biology and pathological mechanisms involved in causing disease is the application of molecular techniques to the various stages of the parasite life cycle. Molecular methods are increasingly contributing to laboratory diagnosis of these conditions with increased yields of positive results though in the tropics it is likely that fecal microscopy will remain the standard for some time to come. The nitroimidazole compounds are the mainstay of treatment for giardia and amebiasis with no major advance in therapeutics since their role was appreciated. Nitazoxanide was shown to be effective for cryptosporidiosis in the 1990s. PMID:22632642

Wright, Stephen G

2012-06-01

33

Role of Leukotrienes on Protozoan and Helminth Infections  

PubMed Central

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

Rogerio, Alexandre P.; Anibal, Fernanda F.

2012-01-01

34

Phylum Arthropoda Phylum Arthropoda  

E-print Network

- venom tubes ­ A few species dangerous to humans · Black widow, brown recluse, hobo(?) · Most spider "bites" are not ­ All predators, (on insects) Class Arachnida SEM of Spider spinnerete & silk Chelicerae chelate (pinching) or venomous fangs or piercing stylets (for sucking body or plant juices) Sun

Wagner, Diane

35

The Termite Group I Phylum Is Highly Diverse and Widespread in the Environment?  

PubMed Central

The bacterial candidate phylum Termite Group I (TG-1) presently consists mostly of “Endomicrobia,” which are endosymbionts of flagellate protists occurring exclusively in the hindguts of termites and wood-feeding cockroaches. Here, we show that public databases contain many, mostly undocumented 16S rRNA gene sequences from other habitats that are affiliated with the TG-1 phylum but are only distantly related to “Endomicrobia.” Phylogenetic analysis of the expanded data set revealed several diverse and deeply branching lineages comprising clones from many different habitats. In addition, we designed specific primers to explore the diversity and environmental distribution of bacteria in the TG-1 phylum. PMID:17704269

Herlemann, Daniel P. R.; Geissinger, Oliver; Brune, Andreas

2007-01-01

36

Necrotizing lung infection caused by the protozoan Balantidium coli  

PubMed Central

Balantidium coli, a ciliated protozoan, is well known to cause intestinal infection in humans. Extraintestinal spread to the peritoneal cavity and genitourinary tract has rarely been reported. There have also been a few cases of lung involvement from this parasite. A case of B coli causing a thick-walled right upper lobe cavity in an organic farmer who had contact with aerosolized pig manure is reported. Bronchoalveolar lavage fluid examined for ova and parasite revealed trophozoites of B coli in large numbers. Treatment with doxycycline hyclate led to marked improvement. Necrotizing lung infection caused by the protozoan B coli should be considered in individuals who report contact with pigs. PMID:18159451

Sharma, Sat; Harding, Godfrey

2003-01-01

37

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

E-print Network

Perkinsus marinus, a protozoan parasite of the Eastern oyster (Crassostrea virginica): effects labeled palmitic acid (FLC16) and phosphatidylcholine (FLPC) and lipase activities in the oyster protozoan incorporation, lipid metabolism, Chromatography, Parasitic protozoan, Perkinsus marinus, Oyster, Crassostrea

Hartley, Troy W.

38

ORIGINAL PAPER Towards an unbiased metabolic profiling of protozoan  

E-print Network

ORIGINAL PAPER Towards an unbiased metabolic profiling of protozoan parasites: optimisation of the analytical approach, consisting of hydrophilic interaction liquid chromatography coupled to LTQ-orbitrap mass is then extracted in cold chloroform/methanol/water 20/60/20 (v/v/v) for 1 h at 4 °C, resulting in both cell

Breitling, Rainer

39

Biomass Control in Waste Air Biotrickling Filters by Protozoan Predation  

E-print Network

Biomass Control in Waste Air Biotrickling Filters by Protozoan Predation Huub H. J. Cox, Marc A as a means of biomass control. Wet biomass for- mation in 23.6-L reactors over a 77-day period was reduced in the biotrickling filter enriched with protozoa. The lower rate of biomass accumulation after the addi- tion

40

Ups and Downs of Mucosal Cellular Immunity against Protozoan Parasites  

Microsoft Academic Search

The intestinal mucosa provides both a physiologic and im- munologic barrier to a wide range of microorganisms and foreign substances. In general, the mucosal immune system is homeostatic despite the considerable antigenic load in the intestine. When an imbalance does occur in the regulation of this response, gut barrier dysfunction and inflammatory bowel disease are observed. Protozoan parasites that gain

LLOYD H. KASPER; DOMINIQUE BUZONI-GATEL

2001-01-01

41

Epizootiology of protozoans in farmed salmonids at northern latitudes  

Microsoft Academic Search

Protozoan ectoparasites were examined in a northern salmonid fish farm over a 10-year period, June 1984–May 1994, by the same researcher, with similar catching and sampling procedures throughout. Husbandry procedures remained constant during the study, e.g., fingerlings were kept in steel tanks and yearlings in both steel tanks and earth ponds. Ichthyobodo necator, Chilodonella hexasticha and Ichthyophthirius multifilürs infections were

Päivi Rintamäki-Kinnunen; E. Tellervo Valtonen

1997-01-01

42

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...

43

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

E-print Network

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

Hartley, Troy W.

44

Evidence for the widespread distribution of CRISPR-Cas system in the Phylum Cyanobacteria  

PubMed Central

Members of the phylum Cyanobacteria inhabit ecologically diverse environments. However, the CRISPR-Cas (clustered regularly interspaced short palindromic repeats, CRISPR associated genes), an extremely adaptable defense system, has not been surveyed in this phylum. We analyzed 126 cyanobacterial genomes and, surprisingly, found CRISPR-Cas in the majority except the marine subclade (Synechococcus and Prochlorococcus), in which cyanophages are a known force shaping their evolution. Multiple observations of CRISPR loci in the absence of cas1/cas2 genes may represent an early stage of losing a CRISPR-Cas locus. Our findings reveal the widespread distribution of their role in the phylum Cyanobacteria and provide a first step to systematically understanding CRISPR-Cas systems in cyanobacteria. PMID:23628889

Cai, Fei; Axen, Seth D.; Kerfeld, Cheryl A.

2013-01-01

45

Reproductive clonality in protozoan pathogens--truth or artefact?  

PubMed

The debate around the frequency and importance of genetic exchange in parasitic protozoa is now several decades old. Recently, fresh assertions have been made that predominant clonal evolution explains the population structures of several key protozoan pathogens. Here, we present an alternative perspective. On the assumption that much apparent clonality may be an artefact of inadequate sampling and study design, we review current research to define why sex might be so difficult to detect in protozoan parasite populations. In doing so, we contrast laboratory models of genetic exchange in parasitic protozoa with natural patterns of genetic diversity and consider the fitness advantage of sex at different evolutionary scales. We discuss approaches to improve the accuracy of efforts to characterize genetic exchange in the field. We also examine the implications of the first population genomic studies for the debate around sex and clonality in parasitic protozoa and discuss caveats for the future. PMID:25060834

Ramírez, Juan David; Llewellyn, Martin S

2014-09-01

46

Targeting protozoan parasite metabolism: glycolytic enzymes in the therapeutic crosshairs.  

PubMed

Glycolysis is an important metabolic pathway for most organisms, including protozoan parasites. Many of these primitive eukaryotes have streamlined their metabolism, favoring glycolysis for generating ATP in the glucose-rich environments in which they reside. Therefore, the enzymes involved in hexose metabolism could prove to be attractive targets for therapeutic development. This hypothesis is supported by a number of chemical and genetic validation studies. Additionally, the peculiar biochemistry of many of the components, along with limited protein sequence identity emphasizes the likelihood of developing compounds that selectively inhibit the parasite enzymes. In this review, we examine the status of target validation at the genetic and/or chemical levels from the protozoan parasites. While the proteins from some species have been interrogated to the point that well-defined lead compounds have been identified with activities against both enzyme and parasite growth, progress in other systems has to date been limited. PMID:24083603

Harris, M T; Mitchell, W G; Morris, J C

2014-01-01

47

Comparative Genomic Analysis of Multi-Subunit Tethering Complexes Demonstrates an Ancient Pan-Eukaryotic Complement and Sculpting in Apicomplexa  

PubMed Central

Apicomplexa are obligate intracellular parasites that cause tremendous disease burden world-wide. They utilize a set of specialized secretory organelles in their invasive process that require delivery of components for their biogenesis and function, yet the precise mechanisms underpinning such processes remain unclear. One set of potentially important components is the multi-subunit tethering complexes (MTCs), factors increasingly implicated in all aspects of vesicle-target interactions. Prompted by the results of previous studies indicating a loss of membrane trafficking factors in Apicomplexa, we undertook a bioinformatic analysis of MTC conservation. Building on knowledge of the ancient presence of most MTC proteins, we demonstrate the near complete retention of MTCs in the newly available genomes for Guillardiatheta and Bigelowiellanatans. The latter is a key taxonomic sampling point as a basal sister taxa to the group including Apicomplexa. We also demonstrate an ancient origin of the CORVET complex subunits Vps8 and Vps3, as well as the TRAPPII subunit Tca17. Having established that the lineage leading to Apicomplexa did at one point possess the complete eukaryotic complement of MTC components, we undertook a deeper taxonomic investigation in twelve apicomplexan genomes. We observed excellent conservation of the VpsC core of the HOPS and CORVET complexes, as well as the core TRAPP subunits, but sparse conservation of TRAPPII, COG, Dsl1, and HOPS/CORVET-specific subunits. However, those subunits that we did identify appear to be expressed with similar patterns to the fully conserved MTC proteins, suggesting that they may function as minimal complexes or with analogous partners. Strikingly, we failed to identify any subunits of the exocyst complex in all twelve apicomplexan genomes, as well as the dinoflagellate Perkinsus marinus. Overall, we demonstrate reduction of MTCs in Apicomplexa and their ancestors, consistent with modification during, and possibly pre-dating, the move from free-living marine algae to deadly human parasites. PMID:24086721

Klinger, Christen M.; Klute, Mary J.; Dacks, Joel B.

2013-01-01

48

Littoral protozoan assemblages from two Mexican hyposaline lakes  

Microsoft Academic Search

Littoral protozoan assemblages from two hyposaline crater-lakes (Lakes Alchichica and Atexcac) located in the Oriental Valley,\\u000a center of Mexico, were studied using the polyurethane foam units (PFU) colonization method. Fifteen PFU (5 dates, three replicates\\u000a per date, 64 72 50 mm) were located in the littoral area of each lake and collected at 8, 14, 20–21, 28–29 and 38–39 d

Alfonso Lugo; Javier Alcocer; Ma. del Rosario Sanchez; Elva Escobar

1998-01-01

49

Phylogenetic Delineation of the Novel Phylum Armatimonadetes (Former Candidate Division OP10) and Definition of Two Novel Candidate Divisions  

PubMed Central

Small-subunit (SSU) rRNA gene sequences associated with the phylum Armatimonadetes were analyzed using multiple phylogenetic methods, clarifying both the phylum boundary and the affiliation of previously ambiguous groupings. Here we define the Armatimonadetes as 10 class-level groups and reclassify two previously associated groups as candidate divisions WS1 and FBP. PMID:23377935

Herbold, C. W.; Dunfield, P. F.; Morgan, X. C.; McDonald, I. R.; Stott, M. B.

2013-01-01

50

Newly Isolated but Uncultivated Magnetotactic Bacterium of the Phylum Nitrospirae from Beijing, China  

PubMed Central

Magnetotactic bacteria (MTB) in the phylum Nitrospirae synthesize up to hundreds of intracellular bullet-shaped magnetite magnetosomes. In the present study, a watermelon-shaped magnetotactic bacterium (designated MWB-1) from Lake Beihai in Beijing, China, was characterized. This uncultivated microbe was identified as a member of the phylum Nitrospirae and represents a novel phylogenetic lineage with ?6% 16S rRNA gene sequence divergence from all currently described MTB. MWB-1 contained 200 to 300 intracellular bullet-shaped magnetite magnetosomes and showed a helical swimming trajectory under homogeneous magnetic fields; its magnetotactic velocity decreased with increasing field strength, and vice versa. A robust phylogenetic framework for MWB-1 and all currently known MTB in the phylum Nitrospirae was constructed utilizing maximum-likelihood and Bayesian algorithms, which yielded strong evidence that the Nitrospirae MTB could be divided into four well-supported groups. Considering its population densities in sediment and its high numbers of magnetosomes, MWB-1 was estimated to account for more than 10% of the natural remanent magnetization of the surface sediment. Taken together, the results of this study suggest that MTB in the phylum Nitrospirae are more diverse than previously realized and can make important contributions to the sedimentary magnetization in particular environments. PMID:22113917

Li, Jinhua; Pan, Yongxin

2012-01-01

51

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

PubMed Central

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

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

2013-01-01

52

Draft Genome Sequence of the Endosymbiont "Candidatus Ruthia magnifica" UCD-CM (Phylum Proteobacteria)  

PubMed Central

Here, we present the draft genome of the endosymbiont “Candidatus Ruthia magnifica” UCD-CM, a member of the phylum Proteobacteria, found from the gills of a deep-sea giant clam, Calyptogena magnifica. The assembly consists of 1,160,249 bp contained in 18 contigs. PMID:25035337

Lee, Ruth D.; Jospin, Guillaume; Coil, David A.

2014-01-01

53

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

PubMed Central

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

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

2012-01-01

54

A phylogenomic and molecular signature based approach for characterization of the phylum Spirochaetes and its major clades: proposal for a taxonomic revision of the phylum  

PubMed Central

The Spirochaetes species cause many important diseases including syphilis and Lyme disease. Except for their containing a distinctive endoflagella, no other molecular or biochemical characteristics are presently known that are specific for either all Spirochaetes or its different families. We report detailed comparative and phylogenomic analyses of protein sequences from Spirochaetes genomes to understand their evolutionary relationships and to identify molecular signatures for this group. These studies have identified 38 conserved signature indels (CSIs) that are specific for either all members of the phylum Spirochaetes or its different main clades. Of these CSIs, a 3 aa insert in the FlgC protein is uniquely shared by all sequenced Spirochaetes providing a molecular marker for this phylum. Seven, six, and five CSIs in different proteins are specific for members of the families Spirochaetaceae, Brachyspiraceae, and Leptospiraceae, respectively. Of the 19 other identified CSIs, 3 are uniquely shared by members of the genera Sphaerochaeta, Spirochaeta, and Treponema, whereas 16 others are specific for the genus Borrelia. A monophyletic grouping of the genera Sphaerochaeta, Spirochaeta, and Treponema distinct from the genus Borrelia is also strongly supported by phylogenetic trees based upon concatenated sequences of 22 conserved proteins. The molecular markers described here provide novel and more definitive means for identification and demarcation of different main groups of Spirochaetes. To accommodate the extensive genetic diversity of the Spirochaetes as revealed by different CSIs and phylogenetic analyses, it is proposed that the four families of this phylum should be elevated to the order level taxonomic ranks (viz. Spirochaetales, Brevinematales ord. nov., Brachyspiriales ord. nov., and Leptospiriales ord. nov.). It is further proposed that the genera Borrelia and Cristispira be transferred to a new family Borreliaceae fam. nov. within the order Spirochaetales. PMID:23908650

Gupta, Radhey S.; Mahmood, Sharmeen; Adeolu, Mobolaji

2013-01-01

55

Physiological Studies of the Rumen Protozoan Ophryoscolex caudatus Eberlein1  

PubMed Central

The rumen ciliate Ophryoscolex caudatus fermented starch with the production of acetic, butyric, and lactic acids plus CO2 and H2. Cellulose was not significantly metabolized although pectin was rapidly attacked in the Warburg apparatus. The protein sources, cottonseed, soybean, and linseed oil meals, and the amino acids, dl-alanine, dl-valine, and dl-leucine, were utilized by the protozoan, whereas ammonia was demonstrated as an end product of nitrogenous metabolism. Methods for the separation of O. caudatus from mixed rumen contents are described. Images FIG. 1 PMID:13785488

Williams, P. P.; Davis, R. E.; Doetsch, R. N.; Gutierrez, J.

1961-01-01

56

Vertebrate Cell Cycle Modulates Infection by Protozoan Parasites  

NASA Astrophysics Data System (ADS)

Synchronized HeLa cell populations were exposed to Trypanosoma cruzi or Toxoplasma gondii, obligate intracellular protozoan parasites that cause Chagas' disease and toxoplasmosis, respectively, in humans. The ability of the two parasites to infect HeLa cells increased as the HeLa cells proceeded from the G1 phase to the S phase of their growth cycle and decreased as the cells entered G2-M. Characterization of the S-phase cell surface components responsible for this phenomenon could be beneficial in the development of vaccines against these parasitic diseases.

Dvorak, James A.; Crane, Mark St. J.

1981-11-01

57

Disseminated granulomas caused by an unidentified protozoan in sandhill cranes  

USGS Publications Warehouse

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.

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

1979-01-01

58

Disseminated granulomas caused by an unidentified protozoan in sandhill cranes.  

PubMed

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

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

1979-11-01

59

Isospora dromaii n. sp. (Apicomplexa, Eimeriidae) isolated from emus, Dromaius novaehollandiae (Casuariiformes, Casuariidae).  

PubMed

A new species of Coccidia (Protozoa: Apicomplexa: Eimeriidae) isolated from emus, Dromaius novaehollandiae, which was observed in Brazil is described and named. Oocysts of Isospora dromaii n. sp. are subspheroidal to ovoid in shape, measure 21.6?×?19.8 ?m, and have a double and smooth wall thickness of approximately 1.4 ?m. In this species, micropyle, oocyst residuum, and polar granules are absent. The sporocysts are slightly ovoid in shape and measure 13.7?×?10.0 ?m. Nipple-like Stieda body and prominent sub-Stieda body are present. The sporocyst residuum is composed of small dispersed granules of varying sizes. The sporozoites are characterized by an oblong refractile body and one centrally located nucleus. This is the first description of isosporid coccidia infecting birds of the family Dromaiidae. PMID:25195056

Dos Santos Teixeira, Carina; Gallo, Samira Salim Mello; Ederli, Nicole Brand; Berto, Bruno Pereira; de Oliveira, Francisco Carlos Rodrigues

2014-11-01

60

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

PubMed

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

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

1987-10-01

61

Distinct gene set in two different lineages of ammonia-oxidizing archaea supports the phylum Thaumarchaeota.  

PubMed

Globally distributed archaea comprising ammonia oxidizers of moderate terrestrial and marine environments are considered the most abundant archaeal organisms on Earth. Based on 16S rRNA phylogeny, initial assignment of these archaea was to the Crenarchaeota. By contrast, features of the first genome sequence from a member of this group suggested that they belong to a novel phylum, the Thaumarchaeota. Here, we re-investigate the Thaumarchaeota hypothesis by including two newly available genomes, that of the marine ammonia oxidizer Nitrosopumilus maritimus and that of Nitrososphaera gargensis, a representative of another evolutionary lineage within this group predominantly detected in terrestrial environments. Phylogenetic studies based on r-proteins and other core genes, as well as comparative genomics, confirm the assignment of these organisms to a separate phylum and reveal a Thaumarchaeota-specific set of core informational processing genes, as well as potentially ancestral features of the archaea. PMID:20598889

Spang, Anja; Hatzenpichler, Roland; Brochier-Armanet, Céline; Rattei, Thomas; Tischler, Patrick; Spieck, Eva; Streit, Wolfgang; Stahl, David A; Wagner, Michael; Schleper, Christa

2010-08-01

62

Phylogenetic Framework and Molecular Signatures for the Main Clades of the Phylum Actinobacteria  

PubMed Central

Summary: The phylum Actinobacteria harbors many important human pathogens and also provides one of the richest sources of natural products, including numerous antibiotics and other compounds of biotechnological interest. Thus, a reliable phylogeny of this large phylum and the means to accurately identify its different constituent groups are of much interest. Detailed phylogenetic and comparative analyses of >150 actinobacterial genomes reported here form the basis for achieving these objectives. In phylogenetic trees based upon 35 conserved proteins, most of the main groups of Actinobacteria as well as a number of their superageneric clades are resolved. We also describe large numbers of molecular markers consisting of conserved signature indels in protein sequences and whole proteins that are specific for either all Actinobacteria or their different clades (viz., orders, families, genera, and subgenera) at various taxonomic levels. These signatures independently support the existence of different phylogenetic clades, and based upon them, it is now possible to delimit the phylum Actinobacteria (excluding Coriobacteriia) and most of its major groups in clear molecular terms. The species distribution patterns of these markers also provide important information regarding the interrelationships among different main orders of Actinobacteria. The identified molecular markers, in addition to enabling the development of a stable and reliable phylogenetic framework for this phylum, also provide novel and powerful means for the identification of different groups of Actinobacteria in diverse environments. Genetic and biochemical studies on these Actinobacteria-specific markers should lead to the discovery of novel biochemical and/or other properties that are unique to different groups of Actinobacteria. PMID:22390973

Gao, Beile

2012-01-01

63

Impact and control of protozoan parasites in maricultured fishes.  

PubMed

SUMMARY Aquaculture, including both freshwater and marine production, has on a world scale exhibited one of the highest growth rates within animal protein production during recent decades and is expected to expand further at the same rate within the next 10 years. Control of diseases is one of the most prominent challenges if this production goal is to be reached. Apart from viral, bacterial, fungal and metazoan infections it has been documented that protozoan parasites affect health and welfare and thereby production of fish in marine aquaculture. Representatives within the main protozoan groups such as amoebae, dinoflagellates, kinetoplastid flagellates, diplomonadid flagellates, apicomplexans, microsporidians and ciliates have been shown to cause severe morbidity and mortality among farmed fish. Well studied examples are Neoparamoeba perurans, Amyloodinium ocellatum, Spironucleus salmonicida, Ichthyobodo necator, Cryptobia salmositica, Loma salmonae, Cryptocaryon irritans, Miamiensis avidus and Trichodina jadranica. The present report provides details on the parasites' biology and impact on productivity and evaluates tools for diagnosis, control and management. Special emphasis is placed on antiprotozoan immune responses in fish and a strategy for development of vaccines is presented. PMID:23448656

Buchmann, Kurt

2013-03-01

64

Chitinase Dependent Control of Protozoan Cyst Burden in the Brain  

PubMed Central

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

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

2012-01-01

65

Gliding Motility and Por Secretion System Genes Are Widespread among Members of the Phylum Bacteroidetes  

PubMed Central

The phylum Bacteroidetes is large and diverse, with rapid gliding motility and the ability to digest macromolecules associated with many genera and species. Recently, a novel protein secretion system, the Por secretion system (PorSS), was identified in two members of the phylum, the gliding bacterium Flavobacterium johnsoniae and the nonmotile oral pathogen Porphyromonas gingivalis. The components of the PorSS are not similar in sequence to those of other well-studied bacterial secretion systems. The F. johnsoniae PorSS genes are a subset of the gliding motility genes, suggesting a role for the secretion system in motility. The F. johnsoniae PorSS is needed for assembly of the gliding motility apparatus and for secretion of a chitinase, and the P. gingivalis PorSS is involved in secretion of gingipain protease virulence factors. Comparative analysis of 37 genomes of members of the phylum Bacteroidetes revealed the widespread occurrence of gliding motility genes and PorSS genes. Genes associated with other bacterial protein secretion systems were less common. The results suggest that gliding motility is more common than previously reported. Microscopic observations confirmed that organisms previously described as nonmotile, including Croceibacter atlanticus, “Gramella forsetii,” Paludibacter propionicigenes, Riemerella anatipestifer, and Robiginitalea biformata, exhibit gliding motility. Three genes (gldA, gldF, and gldG) that encode an apparent ATP-binding cassette transporter required for F. johnsoniae gliding were absent from two related gliding bacteria, suggesting that the transporter may not be central to gliding motility. PMID:23123910

Zhu, Yongtao

2013-01-01

66

Genome Sequence and Methylome of Soil Bacterium Gemmatirosa kalamazoonensis KBS708T, a Member of the Rarely Cultivated Gemmatimonadetes Phylum.  

PubMed

Bacteria belonging to the phylum Gemmatimonadetes are found in a wide variety of environments and are particularly abundant in soils. Here, we present the complete genome sequence and methylation pattern of the newly described Gemmatirosa kalamazoonensis type strain. PMID:24699952

Debruyn, Jennifer M; Radosevich, Mark; Wommack, K Eric; Polson, Shawn W; Hauser, Loren J; Fawaz, Mariam N; Korlach, Jonas; Tsai, Yu-Chih

2014-01-01

67

Genome Sequence and Methylome of Soil Bacterium Gemmatirosa kalamazoonensis KBS708T, a Member of the Rarely Cultivated Gemmatimonadetes Phylum  

PubMed Central

Bacteria belonging to the phylum Gemmatimonadetes are found in a wide variety of environments and are particularly abundant in soils. Here, we present the complete genome sequence and methylation pattern of the newly described Gemmatirosa kalamazoonensis type strain. PMID:24699952

Radosevich, Mark; Wommack, K. Eric; Polson, Shawn W.; Hauser, Loren J.; Fawaz, Mariam N.; Korlach, Jonas; Tsai, Yu-Chih

2014-01-01

68

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

E-print Network

to high water temperatures. D 2004 Elsevier B.V. All rights reserved. Keywords: Fatty acid synthesisIn vitro effects of temperature and salinity on fatty acid synthesis in the oyster protozoan on fatty acid synthetic activities in the oyster protozoan parasite, Perkinsus marinus, were tested

Hartley, Troy W.

69

Interferon in resistance to bacterial and protozoan infections  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

70

Protozoan Parasites of Bivalve Molluscs: Literature Follows Culture  

PubMed Central

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

Fernandez Robledo, Jose A.; Vasta, Gerardo R.; Record, Nicholas R.

2014-01-01

71

Protozoan parasites of bivalve molluscs: literature follows culture.  

PubMed

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

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

2014-01-01

72

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

PubMed

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

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

2014-10-01

73

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

PubMed Central

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

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

2014-01-01

74

The phylogeography of the Placozoa suggests a taxon-rich phylum in tropical and subtropical waters.  

PubMed

Placozoa has been a key phylum for understanding early metazoan evolution. Yet this phylum is officially monotypic and with respect to its general biology and ecology has remained widely unknown. Worldwide sampling and sequencing of the mitochondrial large ribosomal subunit (16S) reveals a cosmopolitan distribution in tropical and subtropical waters of genetically different clades. We sampled a total of 39 tropical and subtropical locations worldwide and found 23 positive sites for placozoans. The number of genetically characterized sites was thereby increased from 15 to 37. The new sampling identified the first genotypes from two new oceanographic regions, the Eastern Atlantic and the Indian Ocean. We found seven out of 11 previously known haplotypes as well as five new haplotypes. One haplotype resembles a new genetic clade, increasing the number of clades from six to seven. Some of these clades seem to be cosmopolitan whereas others appear to be endemic. The phylogeography also shows that different clades occupy different ecological niches and identifies several euryoecious haplotypes with a cosmopolitic distribution as well as some stenoecious haplotypes with an endemic distribution. Haplotypes of different clades differ substantially in their phylogeographic distribution according to latitude. The genetic data also suggest deep phylogenetic branching patterns between clades. PMID:20604867

Eitel, M; Schierwater, B

2010-06-01

75

The first internal molecular phylogeny of the animal phylum Entoprocta (Kamptozoa).  

PubMed

This article provides the first molecular phylogenetic study of the enigmatic invertebrate phylum Entoprocta and was designed to resolve the internal phylogenetic relationships of the taxon. The study is based on partial and combined analyses of the mitochondrial gene cytochrome c oxidase subunit I (COI), as well as the nuclear ribosomal genes 28S rDNA and 18S rDNA. A short morphological character matrix was constructed to trace character evolution along the combined molecular phylogenetic tree. The combined analyses of all three genes strongly support the monophyly of the phylum Entoprocta and a sister group relationship of Entoprocta and Cycliophora, a result which is consistent with a number of previous morphological and molecular assessments. We find evidence for two separate lineages within the Entoprocta, one lineage leading to all recent colonial taxa, Coloniales, another representing the clade of solitary entoprocts, Solitaria. Our study suggests that Loxosomella is a paraphyletic assembly with regard to the genera Loxomitra, Loxosoma, and Loxocorone. The results imply that the ancestral entoproct was a solitary, marine organism with an epizoic life style. The groundplan of the entoproct adult stage probably included a bilobed centralized nervous system, and the larva was assumedly planktonic, with a gut and a ciliated creeping sole. PMID:20398775

Fuchs, Judith; Iseto, Tohru; Hirose, Mamiko; Sundberg, Per; Obst, Matthias

2010-07-01

76

FROM INCIPIENT TO SUBSTANTIAL: EVOLUTION OF PLACENTOTROPHY IN A PHYLUM OF AQUATIC COLONIAL INVERTEBRATES  

PubMed Central

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

Ostrovsky, Andrew N; Fairbairn, D

2013-01-01

77

Anaerobic fungi (phylum Neocallimastigomycota): advances in understanding their taxonomy, life cycle, ecology, role and biotechnological potential.  

PubMed

Anaerobic fungi (phylum Neocallimastigomycota) inhabit the gastrointestinal tract of mammalian herbivores, where they play an important role in the degradation of plant material. The Neocallimastigomycota represent the earliest diverging lineage of the zoosporic fungi; however, understanding of the relationships of the different taxa (both genera and species) within this phylum is in need of revision. Issues exist with the current approaches used for their identification and classification, and recent evidence suggests the presence of several novel taxa (potential candidate genera) that remain to be characterised. The life cycle and role of anaerobic fungi has been well characterised in the rumen, but not elsewhere in the ruminant alimentary tract. Greater understanding of the 'resistant' phase(s) of their life cycle is needed, as is study of their role and significance in other herbivores. Biotechnological application of anaerobic fungi, and their highly active cellulolytic and hemi-cellulolytic enzymes, has been a rapidly increasing area of research and development in the last decade. The move towards understanding of anaerobic fungi using -omics based (genomic, transcriptomic and proteomic) approaches is starting to yield valuable insights into the unique cellular processes, evolutionary history, metabolic capabilities and adaptations that exist within the Neocallimastigomycota. PMID:25046344

Gruninger, Robert J; Puniya, Anil K; Callaghan, Tony M; Edwards, Joan E; Youssef, Noha; Dagar, Sumit S; Fliegerova, Katerina; Griffith, Gareth W; Forster, Robert; Tsang, Adrian; McAllister, Tim; Elshahed, Mostafa S

2014-10-01

78

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

PubMed

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

Volf, J; Koudela, B; Modrý, D

2000-05-01

79

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

PubMed

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

Upton, S J; McKown, R D

1992-01-01

80

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

E-print Network

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 ...

France, Danielle Cook

2007-01-01

81

THE EFFECT OF PTERIDINES ON THE DEVELOPMENTAL CYCLE OF THE PROTOZOAN  

E-print Network

) Institute of Haematology and Blood Transfusion, Unemocnice 1, Praha 2 (Czechoslovakia) SUMMARY Drones, kept infection the drones were killed and the amount of the spores of the protozoan Nosema apis Z

Paris-Sud XI, Université de

82

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

Microsoft Academic Search

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%),

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

2005-01-01

83

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

PubMed

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 T49(T) and its role as a saccharide scavenger in a geothermal steam-affected soil environment. Phylogenomic analysis indicates T49(T) 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 T49(T) 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 T49(T) to cultivation and, by extension, the remaining 'uncultured majority' that have so far evaded conventional microbiological techniques. PMID:24477196

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

2014-07-01

84

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

SciTech Connect

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.

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

85

Stylocephalus occidentalis n. sp. (Apicomplexa: Eugregarinida: Stylocephalidae) from Trimytis pruinosa (Coleoptera: Tenebrionidae) in the Nebraska Sandhills.  

PubMed

Stylocephalus occidentalis n. sp. (Apicomplexa: Eugregarinida) is described from Trimytis pruinosa (Coleoptera: Tenebrionidae) collected from Keith County in the Sandhills of western Nebraska. Measurements are means in micrometers. Developing trophozoites solitary; epimerite a complex of terminal epimerite and intercalating diamerite; epimerite shallowly ovoid to transversely elliptoid, with transverse basal constriction at junction with diamerite, length 0.5-1 times width, approximately 3-4 times that of diamerite; width approximately equal to that of diamerite; diamerite roughly cylindrical to spindle-shaped, without significant anterior taper, little or no evidence of longitudinal folds, length approximately twice width. Association late, frontal, isogamontic. Gamont protomerite depressed ovoid to very broadly ovoid, length 27.3, width 35.1, anterior distance to widest point 15.4. Protomerite-deutomerite septum clearly marked and constricted, width 34.6. Deutomerite often with distinct marginal crenulation, narrowly obovoid to very narrowly obovoid, length 356.5, maximum width 57.6, anterior distance to widest point 26.3, equatorial width 35.1, +/-12.5, 29. Total length 381.5. Nucleus ellipsoid, length 32.5, width 18.8; with 0 or 2 polysomal endosomes. Gametocysts roughly spherical; diameter 205.0; wall desiccating to become paper-like, slightly papillated, dehiscing by simple rupture, releasing oocysts in coiled chains, epispore packet absent, gametocyst residuum present. Oocysts dark brown to black, axially asymmetric, broadly deltoid, gibbous in lateral aspect, slightly keeled in dorsal aspect; length 9.8, height 7.9; with slight terminal protuberances and 2 central, spherical residua. PMID:10864255

Clopton, R E

2000-06-01

86

Sophisticated Adaptations of Gregarina cuneata (Apicomplexa) Feeding Stages for Epicellular Parasitism  

PubMed Central

Background Gregarines represent a very diverse group of early emerging apicomplexans, parasitising numerous invertebrates and urochordates, and are considered of little practical significance. Recently, they have gained more attention since some analyses showed that cryptosporidia are more closely related to the gregarines than to coccidia. Methodology/Principal Findings Using a combined microscopic approach, this study points out the spectacular strategy of Gregarina cuneata for attachment to host tissue and nutrient acquisition while parasitising the intestine of yellow mealworm larvae, and reveals the unusual dynamics of cellular interactions between the host epithelium and parasite feeding stages. Trophozoites of G. cuneata develop epicellularly, attached to the luminal side of the host epithelial cell by an epimerite exhibiting a high degree of morphological variability. The presence of contractile elements in the apical region of feeding stages indicates that trophozoite detachment from host tissue is an active process self-regulated by the parasite. A detailed discussion is provided on the possibility of reversible retraction and protraction of the eugregarine apical end, facilitating eventual reattachment to another host cell in better physiological conditions. The gamonts, found in contact with host tissue via a modified protomerite top, indicate further adaptation of parasite for nutrient acquisition via epicellular parasitism while keeping their host healthy. The presence of eugregarines in mealworm larvae even seems to increase the host growth rate and to reduce the death rate despite often heavy parasitisation. Conclusions/Significance Improved knowledge about the formation of host-parasite interactions in deep-branching apicomplexans, including gregarines, would offer significant insights into the fascinating biology and evolutionary strategy of Apicomplexa. Gregarines exhibit an enormous diversity in cell architecture and dimensions, depending on their parasitic strategy and the surrounding environment. They seem to be a perfect example of a coevolution between a group of parasites and their hosts. PMID:22900033

Valigurová, Andrea

2012-01-01

87

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

PubMed

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

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

2012-10-01

88

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

PubMed Central

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

Cornillot, Emmanuel; Hadj-Kaddour, Kamel; Dassouli, Amina; Noel, Benjamin; Ranwez, Vincent; Vacherie, Benoit; Augagneur, Yoann; Bres, Virginie; Duclos, Aurelie; Randazzo, Sylvie; Carcy, Bernard; Debierre-Grockiego, Francoise; Delbecq, Stephane; Moubri-Menage, Karina; Shams-Eldin, Hosam; Usmani-Brown, Sahar; Bringaud, Frederic; Wincker, Patrick; Vivares, Christian P.; Schwarz, Ralph T.; Schetters, Theo P.; Krause, Peter J.; Gorenflot, Andre; Berry, Vincent; Barbe, Valerie; Ben Mamoun, Choukri

2012-01-01

89

RESEARCH ARTICLE Open Access Involvement of Plasmodium falciparum protein  

E-print Network

be disrupted. Using immunofluorescence and electron microscopy, we examined the intra-erythrocytic stages, a disease caused by parasitic protozoa of the genus Plasmodium (phylum Apicomplexa), is responsible

Boyer, Edmond

90

Use of monodispersed, fluorescently labeled bacteria to estimate in situ protozoan bacterivory.  

PubMed

We have developed a procedure for preparing monodispersed, fluorescently labeled bacteria (FLB), which may be used to measure virtually instantaneous rates of protozoan bacterivory in natural waters. FLB can be prepared both from natural bacterioplankton assemblages and from clonal isolates and can be stored in frozen suspension or freeze-dried without apparent loss of fluorescence intensity. They are not toxic to protozoa and can be metabolized to support bacterivorous protozoan growth rates equal to those on the same strain of unstained, viable bacteria. In experiments comparing uptake of FLB with uptake of fluorescent latex microspheres by protozoan assemblages in a salt marsh tidal creek, we found that both pelagic oligotrichous ciliates and phagotrophic flagellates ingested FLB with a frequency 4- to 10-fold greater than they ingested the microspheres. Consequently, it appears that the use of latex microspheres leads to underestimation of protozoan bacterivory and that the FLB technique is superior for estimating instantaneous rates of in situ protozoan grazing on bacterioplankton. PMID:16347355

Sherr, B F; Sherr, E B; Fallon, R D

1987-05-01

91

Evolution of apoptosis-like programmed cell death in unicellular protozoan parasites  

PubMed Central

Apoptosis-like programmed cell death (PCD) has recently been described in multiple taxa of unicellular protists, including the protozoan parasites Plasmodium, Trypanosoma and Leishmania. Apoptosis-like PCD in protozoan parasites shares a number of morphological features with programmed cell death in multicellular organisms. However, both the evolutionary explanations and mechanisms involved in parasite PCD are poorly understood. Explaining why unicellular organisms appear to undergo 'suicide' is a challenge for evolutionary biology and uncovering death executors and pathways is a challenge for molecular and cell biology. Bioinformatics has the potential to integrate these approaches by revealing homologies in the PCD machinery of diverse taxa and evaluating their evolutionary trajectories. As the molecular mechanisms of apoptosis in model organisms are well characterised, and recent data suggest similar mechanisms operate in protozoan parasites, key questions can now be addressed. These questions include: which elements of apoptosis machinery appear to be shared between protozoan parasites and multicellular taxa and, have these mechanisms arisen through convergent or divergent evolution? We use bioinformatics to address these questions and our analyses suggest that apoptosis mechanisms in protozoan parasites and other taxa have diverged during their evolution, that some apoptosis factors are shared across taxa whilst others have been replaced by proteins with similar biochemical activities. PMID:21439063

2011-01-01

92

Humanized HLA-DR4 mice fed with the protozoan pathogen of oysters Perkinsus marinus (Dermo) do not develop noticeable pathology but elicit systemic immunity.  

PubMed

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.EA(0)) in such a way that CD4 T cell responses are solely restricted by the human HLA-DR4 molecule. The DR4.EA(0) 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.EA(0) 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.EA(0) 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

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

2014-01-01

93

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

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

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

2014-01-01

94

Occurrence and diurnal population fluctuations of the ruminal protozoan Microcetus lappus.  

PubMed Central

A series of experiments with bison and cattle were conducted to obtain information on the relatively uncommon ruminal protozoan Microcetus lappus. Although M. lappus is a holotrich, diurnal changes in concentrations indicate that it follows a cycle unlike most other holotrichs, decreasing shortly after feed is offered and then gradually increasing over time. Concentrations of M. lappus varied widely among animals, exceeding 50% of the total protozoan population in some cattle. In bison, Microcetus concentrations averaged 2% of the protozoan population. Dietary protein and energy levels apparently did not influence Microcetus numbers. The highest concentrations of M. lappus were found in the reticulum, whereas the lowest numbers occurred in the mid-dorsal sac. PMID:2495765

Towne, G; Nagaraja, T G

1989-01-01

95

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

PubMed Central

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

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

2012-01-01

96

Diversity of freshwater Thioploca species and their specific association with filamentous bacteria of the phylum Chloroflexi.  

PubMed

Phylogenetic diversity among filamentous sulfur-oxidizing bacteria of the genus Thioploca inhabiting freshwater/brackish environments was analyzed in detail. The 16S rRNA gene sequence of Thioploca found in a freshwater lake in Japan, Lake Okotanpe, was identical to that of Thioploca from Lake Ogawara, a brackish lake. The samples of the two lakes could be differentiated by the sequences of their 23S rRNA genes and 16S-23S rRNA internal transcribed spacer (ITS) regions. The 23S rRNA-based phylogenetic relationships between Thioploca samples from four lakes (Lake Okotanpe, Lake Ogawara, Lake Biwa, and Lake Constance) were similar to those based on the 16S rRNA gene sequences. In addition, multiple types of the ITS sequences were obtained from Thioploca inhabiting Lake Okotanpe and Lake Constance. Variations within respective Thioploca populations were also observed in the analysis of the soxB gene, involved in sulfur oxidation. As major members of the sheath-associated microbial community, bacteria of the phylum Chloroflexi were consistently detected in the samples from different lakes. Fluorescence in situ hybridization revealed that they were filamentous and abundantly distributed within the sheaths of Thioploca. PMID:21800088

Nemoto, Fumiko; Kojima, Hisaya; Fukui, Manabu

2011-11-01

97

Porifera a reference phylum for evolution and bioprospecting: the power of marine genomics.  

PubMed

The term Urmetazoa, as the hypothetical metazoan ancestor, was introduced to highlight the finding that all metazoan phyla including the Porifera [sponges] derived from one common ancestor. Analyses of sponge genomes, from Demospongiae, Calcarea and Hexactinellida have permitted the reconstruction of the evolutionary trail from Fungi to Metazoa. This has provided evidence that the characteristic evolutionary novelties of Metazoa existing in Porifera share high sequence similarities and in some aspects also functional similarities to related polypeptides found in other metazoan phyla. It is surprising that the genome of Porifera is large and comprises substantially more genes than Protostomia and Deuterostomia. On the basis of solid taxonomy and ecological data, the high value of this phylum for human application becomes obvious especially with regard to the field of chemical ecology and the hope to find novel potential drugs for clinical use. In addition, the benefit of efforts in understanding molecular biodiversity with focus on sponges can be seen in the fact that these animals as "living fossils" allow to stethoscope into the past of our globe especially with respect to the evolution of Metazoa. PMID:15477729

Müller, Werner E G; Schwertner, Heiko; Müller, Isabel M

2004-09-01

98

Operon Conservation and the Evolution of trans-Splicing in the Phylum Nematoda  

PubMed Central

The nematode Caenorhabditis elegans is unique among model animals in that many of its genes are cotranscribed as polycistronic pre-mRNAs from operons. The mechanism by which these operonic transcripts are resolved into mature mRNAs includes trans-splicing to a family of SL2-like spliced leader exons. SL2-like spliced leaders are distinct from SL1, the major spliced leader in C. elegans and other nematode species. We surveyed five additional nematode species, representing three of the five major clades of the phylum Nematoda, for the presence of operons and the use of trans-spliced leaders in resolution of polycistronic pre-mRNAs. Conserved operons were found in Pristionchus pacificus, Nippostrongylus brasiliensis, Strongyloides ratti, Brugia malayi, and Ascaris suum. In nematodes closely related to the rhabditine C. elegans, a related family of SL2-like spliced leaders is used for operonic transcript resolution. However, in the tylenchine S. ratti operonic transcripts are resolved using a family of spliced leaders related to SL1. Non-operonic genes in S. ratti may also receive these SL1 variants. In the spirurine nematodes B. malayi and A. suum operonic transcripts are resolved using SL1. Mapping these phenotypes onto the robust molecular phylogeny for the Nematoda suggests that operons evolved before SL2-like spliced leaders, which are an evolutionary invention of the rhabditine lineage. PMID:17121468

Guiliano, David B; Blaxter, Mark L

2006-01-01

99

Genomic insights into the uncultured genus 'Candidatus Magnetobacterium' in the phylum Nitrospirae.  

PubMed

Magnetotactic bacteria (MTB) of the genus 'Candidatus Magnetobacterium' in phylum Nitrospirae are of great interest because of the formation of hundreds of bullet-shaped magnetite magnetosomes in multiple bundles of chains per cell. These bacteria are worldwide distributed in aquatic environments and have important roles in the biogeochemical cycles of iron and sulfur. However, except for a few short genomic fragments, no genome data are available for this ecologically important genus, and little is known about their metabolic capacity owing to the lack of pure cultures. Here we report the first draft genome sequence of 3.42?Mb from an uncultivated strain tentatively named 'Ca. Magnetobacterium casensis' isolated from Lake Miyun, China. The genome sequence indicates an autotrophic lifestyle using the Wood-Ljungdahl pathway for CO2 fixation, which has not been described in any previously known MTB or Nitrospirae organisms. Pathways involved in the denitrification, sulfur oxidation and sulfate reduction have been predicted, indicating its considerable capacity for adaptation to variable geochemical conditions and roles in local biogeochemical cycles. Moreover, we have identified a complete magnetosome gene island containing mam, mad and a set of novel genes (named as man genes) putatively responsible for the formation of bullet-shaped magnetite magnetosomes and the arrangement of multiple magnetosome chains. This first comprehensive genomic analysis sheds light on the physiology, ecology and biomineralization of the poorly understood 'Ca. Magnetobacterium' genus. PMID:24914800

Lin, Wei; Deng, Aihua; Wang, Zhang; Li, Ying; Wen, Tingyi; Wu, Long-Fei; Wu, Martin; Pan, Yongxin

2014-12-01

100

'Candidatus Thermochlorobacter aerophilum:' an aerobic chlorophotoheterotrophic member of the phylum Chlorobi defined by metagenomics and metatranscriptomics  

PubMed Central

An uncultured member of the phylum Chlorobi, provisionally named ‘Candidatus Thermochlorobacter aerophilum', occurs in the microbial mats of alkaline siliceous hot springs at the Yellowstone National Park. ‘Ca. T. aerophilum' was investigated through metagenomic and metatranscriptomic approaches. ‘Ca. T. aerophilum' is a member of a novel, family-level lineage of Chlorobi, a chlorophototroph that synthesizes type-1 reaction centers and chlorosomes similar to cultivated relatives among the green sulfur bacteria, but is otherwise very different physiologically. ‘Ca. T. aerophilum' is proposed to be an aerobic photoheterotroph that cannot oxidize sulfur compounds, cannot fix N2, and does not fix CO2 autotrophically. Metagenomic analyses suggest that ‘Ca. T. aerophilum' depends on other mat organisms for fixed carbon and nitrogen, several amino acids, and other important nutrients. The failure to detect bchU suggests that ‘Ca. T. aerophilum' synthesizes bacteriochlorophyll (BChl) d, and thus it occupies a different ecological niche than other chlorosome-containing chlorophototrophs in the mat. Transcription profiling throughout a diel cycle revealed distinctive gene expression patterns. Although ‘Ca. T. aerophilum' probably photoassimilates organic carbon sources and synthesizes most of its cell materials during the day, it mainly transcribes genes for BChl synthesis during late afternoon and early morning, and it synthesizes and assembles its photosynthetic apparatus during the night. PMID:22456447

Liu, Zhenfeng; Klatt, Christian G; Ludwig, Marcus; Rusch, Douglas B; Jensen, Sheila I; Kuhl, Michael; Ward, David M; Bryant, Donald A

2012-01-01

101

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

PubMed

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

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

102

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

PubMed Central

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.

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

2014-01-01

103

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...

104

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

Microsoft Academic Search

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

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

2011-01-01

105

Genomic Analysis of "Elusimicrobium minutum," the First Cultivated Representative of the Phylum "Elusimicrobia" (Formerly Termite Group 1)? †  

PubMed Central

Organisms of the candidate phylum termite group 1 (TG1) are regularly encountered in termite hindguts but are present also in many other habitats. Here, we report the complete genome sequence (1.64 Mbp) of “Elusimicrobium minutum” strain Pei191T, the first cultured representative of the TG1 phylum. We reconstructed the metabolism of this strictly anaerobic bacterium isolated from a beetle larva gut, and we discuss the findings in light of physiological data. E. minutum has all genes required for uptake and fermentation of sugars via the Embden-Meyerhof pathway, including several hydrogenases, and an unusual peptide degradation pathway comprising transamination reactions and leading to the formation of alanine, which is excreted in substantial amounts. The presence of genes encoding lipopolysaccharide biosynthesis and the presence of a pathway for peptidoglycan formation are consistent with ultrastructural evidence of a gram-negative cell envelope. Even though electron micrographs showed no cell appendages, the genome encodes many genes putatively involved in pilus assembly. We assigned some to a type II secretion system, but the function of 60 pilE-like genes remains unknown. Numerous genes with hypothetical functions, e.g., polyketide synthesis, nonribosomal peptide synthesis, antibiotic transport, and oxygen stress protection, indicate the presence of hitherto undiscovered physiological traits. Comparative analysis of 22 concatenated single-copy marker genes corroborated the status of “Elusimicrobia” (formerly TG1) as a separate phylum in the bacterial domain, which was so far based only on 16S rRNA sequence analysis. PMID:19270133

Herlemann, D. P. R.; Geissinger, O.; Ikeda-Ohtsubo, W.; Kunin, V.; Sun, H.; Lapidus, A.; Hugenholtz, P.; Brune, A.

2009-01-01

106

The correlation between Clostridium-difficile infection and human gut concentrations of Bacteroidetes phylum and clostridial species.  

PubMed

We aimed to assess differences in bacterial intensities of Bacteroidetes phylum and different clostridial species in the human intestines with respect to C. difficile infection. Patients with a stool assay for C. difficile toxin were identified via the microbiology laboratory in our institute. Bacterial populations were quantified from stool samples of four groups of patients: Group I-patients with C. difficile associated diarrhea (CDAD); Group II-asymptomatic C. difficile carriers; Group III-patients with non-C. difficile diarrhea; Group IV-patients with no diarrhea and negative stool samples for the C. difficile toxin (control group). Stool was examined for three genes-C. difficile toxin A gene, 16S rRNA gene from Clostridium thermocellum representing other clostridial species, and 16S rRNA gene from Bacteroides fragilis representing the Bacteroidetes phylum. Fifty-nine patients underwent analysis of the stool (CDAD group 14, carriers group 14, non-C. difficile diarrhea group 16, control group 15). C. difficile concentration was highest in the CDAD group, followed by the carriers group. Higher concentrations of both clostridial species and Bacteriodetes were observed in the control and non-C. difficile diarrhea groups compared to the CDAD and carriers groups. We demonstrated an inverse association between infection with C. difficile and the abundance of Bacteroidetes phylum and other clostridial species in human intestines. Studies with larger samples and broader diagnostic procedures are needed in order to better explore and understand this association. PMID:24048726

Goldberg, E; Amir, I; Zafran, M; Gophna, U; Samra, Z; Pitlik, S; Bishara, J

2014-03-01

107

Genome analysis of Elusimicrobium minutum, the first cultivated representative of the Elusimicrobia phylum (formerly Termite Group 1)  

SciTech Connect

The candidate phylum Termite group 1 (TG1), is regularly 1 encountered in termite hindguts but is present also in many other habitats. Here we report the complete genome sequence (1.64 Mbp) of Elusimicrobium minutum strain Pei191{sup T}, the first cultured representative of the TG1 phylum. We reconstructed the metabolism of this strictly anaerobic bacterium isolated from a beetle larva gut and discuss the findings in light of physiological data. E. minutum has all genes required for uptake and fermentation of sugars via the Embden-Meyerhof pathway, including several hydrogenases, and an unusual peptide degradation pathway comprising transamination reactions and leading to the formation of alanine, which is excreted in substantial amounts. The presence of genes encoding lipopolysaccharide biosynthesis and the presence of a pathway for peptidoglycan formation are consistent with ultrastructural evidence of a Gram-negative cell envelope. Even though electron micrographs showed no cell appendages, the genome encodes many genes putatively involved in pilus assembly. We assigned some to a type II secretion system, but the function of 60 pilE-like genes remains unknown. Numerous genes with hypothetical functions, e.g., polyketide synthesis, non-ribosomal peptide synthesis, antibiotic transport, and oxygen stress protection, indicate the presence of hitherto undiscovered physiological traits. Comparative analysis of 22 concatenated single-copy marker genes corroborated the status of Elusimicrobia (formerly TG1) as a separate phylum in the bacterial domain, which was so far based only on 16S rRNA sequence analysis.

Herlemann, D. P. R.; Geissinger, O.; Ikeda-Ohtsubo, W.; Kunin, V.; Sun, H.; Lapidus, A.; Hugenholtz, P.; Brune, A.

2009-02-01

108

Postinoculation Protozoan Establishment and Association Patterns of Methanogenic Archaea in the Ovine Rumen  

Microsoft Academic Search

Association patterns between archaea and rumen protozoa were evaluated by analyzing archaeal 16S rRNA gene clone libraries from ovine rumen inoculated with different protozoa. Five protozoan inoculation treat- ments, fauna free (negative control), holotrich and cellulolytic protozoa, Isotricha and Dasytricha spp., Ento- dinium spp., and total fauna (type A) were tested. We used denaturing gradient gel electrophoresis, quantitative PCR, and

Samuel Ohene-Adjei; Ronald M. Teather; Michael Ivan; Robert J. Forster

2007-01-01

109

Comparing the tolerance limits of selected bacterial and protozoan species to nickel in wastewater systems  

Microsoft Academic Search

Heavy-metal resistant microorganisms play a significant role in the treatment of industrial wastewater. The detoxifying ability of these resistant microorganisms can be manipulated for bioremediation of heavy metals in wastewater systems. This study aimed at comparing the tolerance limit of selected wastewater protozoan species (Aspidisca sp., Trachelophyllum sp. and Peranema sp.) against Ni2+ with that of selected bacterial species (Bacillus

I. Kamika; M. N. B. Momba

2011-01-01

110

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...

111

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

Microsoft Academic Search

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

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

2010-01-01

112

Persistence of Free-Living Protozoan Communities across Rearing Cycles in Commercial Poultry Houses ?  

PubMed Central

The introduction and survival of zoonotic bacterial pathogens in poultry farming have been linked to bacterial association with free-living protozoa. To date, however, no information is available on the persistence of protozoan communities in these environments across consecutive rearing cycles and how it is affected by farm- and habitat-specific characteristics and management strategies. We therefore investigated the spatial and temporal dynamics of free-living protozoa in three habitats (pipeline, water, and miscellaneous samples) in three commercial poultry houses across three rearing cycles by using the molecular fingerprinting technique denaturing gradient gel electrophoresis (DGGE). Our study provides strong evidence for the long-term (ca. 6-month) persistence of protozoa in broiler houses across consecutive rearing cycles. Various free-living protozoa (flagellates, ciliates, and amoebae), including known vectors of bacterial pathogens, were observed during the down periods in between rearing cycles. In addition, multivariate analysis and variation partitioning showed that the protozoan community structure in the broiler houses showed almost no change across rearing cycles and remained highly habitat and farm specific. Unlike in natural environments, protozoan communities inside broiler houses are therefore not seasonal. Our results imply that currently used biosecurity measures (cleaning and disinfection) applied during the down periods are not effective against many protozoans and therefore cannot prevent potential cross-contamination of bacterial pathogens via free-living protozoa between rearing cycles. PMID:21239551

Bare, Julie; Houf, Kurt; Verstraete, Tine; Vaerewijck, Mario; Sabbe, Koen

2011-01-01

113

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

E-print Network

-mutually exclusive hypothe- ses must also be tested. Here, we explain the evolutionary concepts that can explainReview The Meaning of Death: Evolution and Ecology of Apoptosis in Protozoan Parasites Sarah E, we set up the central evolutionary concepts that are expected to ultimately explain apoptosis

Gardner, Andy

114

Phospholipid biosynthesis in the oyster protozoan parasite, Perkinsus Eric D. Lund, Fu-Lin E. Chu *  

E-print Network

Phospholipid biosynthesis in the oyster protozoan parasite, Perkinsus marinus Eric D. Lund, Fu, the Eastern oyster Crassostrea virginica. In order to understand the hostÁ/parasite relationship in lipid B.V. Keywords: Crassostrea virginica; Lipid biosynthesis; Oyster; Oyster parasite; Perkinsus marinus

Hartley, Troy W.

115

Rab5b localization to early endosomes in the protozoan human pathogen Leishmania donovani  

Microsoft Academic Search

Leishmania donovani is a primitive trypanosomatid pathogen of humans. This protozoan is apically polarized such that the flagellar reservoir, the exclusive site of endocytosis and exocytosis, is situated at the anterior end. Recent evidence for the existence of an endocytic pathway in Leishmania has prompted us to investigate candidate temporal markers for endocytosis. In this study we identify the L.

Diane E. Marotta; Noel Gerald; Dennis M. Dwyer

2006-01-01

116

Antidepressants Cause Lethal Disruption of Membrane Function in the Human Protozoan Parasite Leishmania  

Microsoft Academic Search

The antidepressant compounds clomipramine and nitroimipramine were cidal to extracellular promastigotes of both human protozoan parasites Leishmania donovani and Leishmania major. Clomipramine also killed amastigotes of both species within murine macrophages with no apparent toxicity to the host cells. Further, amastigotes were more sensitive than promastigotes to clomipramine. Clomipramine (100 micromoles per liter or 0.2 nanomole per 1 × 106

Dan Zilberstein; Dennis M. Dwyer

1984-01-01

117

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

Microsoft Academic Search

The discovery that an apoptosis-like, programmed cell death (PCD) occurs in a broad range of protozoan parasites offers novel therapeutic tools to treat some of the most serious infectious diseases of humans, companion animals, wildlife, and livestock. Whilst apoptosis is an essential part of normal development, maintenance, and defence in multicellular organisms, its occurrence in unicellular parasites appears counter-intuitive and

Sarah E. Reece; Laura C. Pollitt; Nick Colegrave; Andy Gardner

2011-01-01

118

Epigenetic mechanisms regulate stage differentiation in the minimized protozoan Giardia lambliammi_7062 1..20  

E-print Network

Epigenetic mechanisms regulate stage differentiation in the minimized protozoan Giardia lambliammi, Switzerland. 4 UMR5163, Laboratoire Adaptation et Pathogénie des Micro-organismes, Centre National de la expression patterns. In this study we explored the effect of HDAC inhibition on the life cycle of the human

Caflisch, Amedeo

119

On the Extent and Origins of Genic Novelty in the Phylum Nematoda  

PubMed Central

Background The phylum Nematoda is biologically diverse, including parasites of plants and animals as well as free-living taxa. Underpinning this diversity will be commensurate diversity in expressed genes, including gene sets associated specifically with evolution of parasitism. Methods and Findings Here we have analyzed the extensive expressed sequence tag data (available for 37 nematode species, most of which are parasites) and define over 120,000 distinct putative genes from which we have derived robust protein translations. Combined with the complete proteomes of Caenorhabditis elegans and Caenorhabditis briggsae, these proteins have been grouped into 65,000 protein families that in turn contain 40,000 distinct protein domains. We have mapped the occurrence of domains and families across the Nematoda and compared the nematode data to that available for other phyla. Gene loss is common, and in particular we identify nearly 5,000 genes that may have been lost from the lineage leading to the model nematode C. elegans. We find a preponderance of novelty, including 56,000 nematode-restricted protein families and 26,000 nematode-restricted domains. Mapping of the latest time-of-origin of these new families and domains across the nematode phylogeny revealed ongoing evolution of novelty. A number of genes from parasitic species had signatures of horizontal transfer from their host organisms, and parasitic species had a greater proportion of novel, secreted proteins than did free-living ones. Conclusions These classes of genes may underpin parasitic phenotypes, and thus may be targets for development of effective control measures. PMID:18596977

Wasmuth, James; Schmid, Ralf; Hedley, Ann; Blaxter, Mark

2008-01-01

120

Analysis of the Na+/Ca2+ Exchanger Gene Family within the Phylum Nematoda  

PubMed Central

Na+/Ca2+ exchangers are low affinity, high capacity transporters that rapidly transport calcium at the plasma membrane, mitochondrion, endoplasmic (and sarcoplasmic) reticulum, and the nucleus. Na+/Ca2+ exchangers are widely expressed in diverse cell types where they contribute homeostatic balance to calcium levels. In animals, Na+/Ca2+ exchangers are divided into three groups based upon stoichiometry: Na+/Ca2+ exchangers (NCX), Na+/Ca2+/K+ exchangers (NCKX), and Ca2+/Cation exchangers (CCX). In mammals there are three NCX genes, five NCKX genes and one CCX (NCLX) gene. The genome of the nematode Caenorhabditis elegans contains ten Na+/Ca2+ exchanger genes: three NCX; five CCX; and two NCKX genes. Here we set out to characterize structural and taxonomic specializations within the family of Na+/Ca2+ exchangers across the phylum Nematoda. In this analysis we identify Na+/Ca2+ exchanger genes from twelve species of nematodes and reconstruct their phylogenetic and evolutionary relationships. The most notable feature of the resulting phylogenies was the heterogeneous evolution observed within exchanger subtypes. Specifically, in the case of the CCX exchangers we did not detect members of this class in three Clade III nematodes. Within the Caenorhabditis and Pristionchus lineages we identify between three and five CCX representatives, whereas in other Clade V and also Clade IV nematode taxa we only observed a single CCX gene in each species, and in the Clade III nematode taxa that we sampled we identify NCX and NCKX encoding genes but no evidence of CCX representatives using our mining approach. We also provided re-annotation for predicted CCX gene structures from Heterorhabditis bacteriophora and Caenorhabditis japonica by RT-PCR and sequencing. Together, these findings reveal a complex picture of Na+/Ca2+ transporters in nematodes that suggest an incongruent evolutionary history of proteins that provide central control of calcium dynamics. PMID:25397810

He, Chao; O'Halloran, Damien M.

2014-01-01

121

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

PubMed Central

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

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

2007-01-01

122

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

PubMed Central

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

2008-01-01

123

Postinoculation Protozoan Establishment and Association Patterns of Methanogenic Archaea in the Ovine Rumen?  

PubMed Central

Association patterns between archaea and rumen protozoa were evaluated by analyzing archaeal 16S rRNA gene clone libraries from ovine rumen inoculated with different protozoa. Five protozoan inoculation treatments, fauna free (negative control), holotrich and cellulolytic protozoa, Isotricha and Dasytricha spp., Entodinium spp., and total fauna (type A) were tested. We used denaturing gradient gel electrophoresis, quantitative PCR, and phylogenetic analysis to evaluate the impact of the protozoan inoculants on the respective archaeal communities. Protozoan 18S ribosomal DNA clone libraries were also evaluated to monitor the protozoal population that was established by the inoculation. Phylogenetic analysis suggested that archaeal clones associated with the fauna-free, the Entodinium, and the type A inoculations clustered primarily with uncultured phylotypes. Polyplastron multivesiculatum was the predominant protozoan strain established by the holotrich and cellulolytic protozoan treatment, and this resulted predominantly in archaeal clones affiliated with uncultured and cultured methanogenic phylotypes (Methanosphaera stadtmanae, Methanobrevibacter ruminantium, and Methanobacterium bryantii). Furthermore, the Isotricha and Dasytricha inoculation treatment resulted primarily in archaeal clones affiliated with Methanobrevibacter smithii. This report provides the first assessment of the influence of protozoa on archaea within the rumen microbial community and provides evidence to suggest that different archaeal phylotypes associate with specific groups of protozoa. The observed patterns may be linked to the evolution of commensal and symbiotic relationships between archaea and protozoa in the ovine rumen environment. This report further underscores the prevalence and potential importance of a rather large group of uncultivated archaea in the ovine rumen, probably unrelated to known methanogens and undocumented in the bovine rumen. PMID:17513586

Ohene-Adjei, Samuel; Teather, Ronald M.; Ivan, Michael; Forster, Robert J.

2007-01-01

124

Apicomplexa primers amplify Proteromonas (Stramenopiles, Slopalinida, Proteromonadidae) in tissue and blood samples from lizards.  

PubMed

Microscopy has traditionally been the most common method in parasitological studies, but in recent years molecular screening has become increasingly frequent to detect protozoan parasites in a wide range of vertebrate hosts and vectors. During routine molecular screening of apicomplexan parasites in reptiles using the 18S rRNA gene, we have amplified and sequenced Proteromonas parasites from three lizard hosts (less than 1% prevalence). We conducted phylogenetic analysis to confirm the taxonomic position and infer their relationships with other stramenopiles. Although our phylogeny is limited due to scarcity of molecular data on these protists, our results confirm they are closely related to Proteromonas lacertae. Our findings show that unexpected parasites can be amplified from host samples (blood and tissue) using general procedures to detect hemoparasites, and stress that positive PCR amplifications alone should not be considered as definitive proof of infection by particular parasites. Further validation by sequence confirmation and thorough phylogenetic assessment will not only avoid false positives and biased prevalence estimates but also provide valuable information on the biodiversity and phylogenetic relationships of other parasitic organisms. More generally, our results illustrate the perils of general diagnosis protocols in parasitological studies and the need of cross-validation procedures. PMID:23129192

Maia, João P M C; Gómez-Díaz, Elena; Harris, D James

2012-12-01

125

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

PubMed

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

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

2008-07-31

126

Calcium signaling and endoplasmic reticulum dynamics during fertilization in marine protostome worms belonging to the phylum Nemertea.  

PubMed

Metaphase-I-arrested eggs of marine protostome worms in the phylum Nemertea generate a series of point-source calcium waves during fertilization. Such calcium oscillations depend on inositol-1,4,5-trisphosphate-mediated calcium release from endoplasmic reticulum (ER) stores that undergo structural reorganizations prior to and after fertilization. This article reviews fertilization-induced calcium transients and ER dynamics in nemertean eggs and compares these topics to what has been reported for other animals in order to identify unifying characteristics and distinguishing features of calcium responses during fertilization across the animal kingdom. PMID:24721427

Stricker, Stephen A

2014-08-01

127

Protozoan pulses unveil their pivotal position within the soil food web.  

PubMed

Protozoa are one of the most abundant groups of bacterivores within the soil and are responsible for mineralisation of bacterial biomass, having a large impact on C and N cycling. Little is known of their contribution to soil nutrient transfers or the identity of their consumers. Here, for the first time indigenous flagellates and ciliates, enriched to 83 atom% for (13)C and 10 atom% for (15)N, were introduced to soil cores from two different land managements, grassland and woodland with the same soil type, to trace the flow of protozoan C and N through the soil food web. Nematodes, Collembola, earthworms and insect larvae obtained the greatest amounts of C and N of protozoan origin, either through direct consumption or uptake of biomass post-cell death. Our results show that changes in management, affect the functioning of the soil food web and the utilisation of protozoa as a food source. PMID:21990016

Crotty, Felicity V; Adl, Sina M; Blackshaw, Rod P; Murray, Philip J

2012-05-01

128

Cellulase and other polymer-hydrolyzing activities of Trichomitopsis termopsidis, a symbiotic protozoan from termites  

SciTech Connect

Crude extracts of the anaerobic, cellulolytic protozoan Trichomitopsis termopsidis possessed endo-..beta..-1,4-glucanase and cellobiase activities, as evidenced by hydrolytic action on carboxymethyl cellulose and cellobiose, respectively. Cell extracts also hydrolyzed microcrystalline cellulose. Hydrolysis of microcrystalline cellulose displayed optima at pH 5 and at 30 degrees C, and glucose was the sole product liberated. Cellulolytic activities of T. termopsidis appeared to be entirely cell associated. Hydrolytic activity was also detected against Douglas fir wood powder, xylan, starch, and protein, but not chitin. The importance of these enyzmes in the nutrition of T. termopsidis is discussed in terms of the natural habitat of this protozoan (the hindgut of wood-eating termites). 31 references.

Odelson, D.A.; Breznak, J.A.

1985-03-01

129

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

PubMed

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

Ali, Vahab; Nozaki, Tomoyoshi

2013-01-01

130

Protozoan parasites in cultured mussels Mytilus galloprovincialis in the Thermaikos Gulf (north Aegean Sea, Greece).  

PubMed

The protozoans Ancistrum mytili (Oligohymenophorea: Ancistridae) and Marteilia refringens/maurini (Marteiliidea: Marteiliidae) were found parasitizing cultured mussels Mytilus galloprovincialis L. in the Thermaikos Gulf (north Aegean Sea, Greece). The former did not affect the condition index of infected mussels, in contrast to the latter, which did so and which also induced hemocyte infiltration in the affected digestive epithelium. The prevalence of both parasites was relatively high in a polluted area. PMID:16903237

Rayyan, Abdalnasser; Damianidis, Panagiotis; Antoniadou, Chryssanthi; Chintiroglou, Chariton C

2006-06-23

131

Surface Membrane Carbohydrate Alterations of a Flagellated Protozoan Mediated by Bacterial Endosymbiotes  

Microsoft Academic Search

Crithidia oncopelti, a parasitic trypanosomatid protozoan of insects, normally contains intracellular symbiotic bacteria. As shown earlier, the protozoa can be rid of their endosymbiotes by chloramphenicol, producing a symbiote-free cell line. Here surface-membrane carbohydrate ligands of the symbiote-containing and symbiote-free strains were compared by lectin-mediated agglutination, lectin-ultrastructure localization, [3H]lectin-binding, and fluorescent lectin staining. Symbiote-free organisms consistently had 3-fold higher agglutination

Dennis M. Dwyer; Kwang-Poo Chang

1976-01-01

132

Protozoan Parasite of Humans: Surface Membrane with Externally Disposed Acid Phosphatase  

Microsoft Academic Search

Plasma membranes isolated from the protozoan parasite Leishmania donovani were enriched in acid phosphatase (E.C.3.1.3.2) activity. Cytochemically, the enzyme was distributed uniformly on the surface of intact cells and was localized on the external face of isolated membranes. Physical characteristics and orientation of the membrane-bound enzyme suggest that the organism is adapted for existence in hydrolytic environments.

Michael Gottlieb; Dennis M. Dwyer

1981-01-01

133

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

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

Cook, Tamara J; Smith-Herron, Autumn J

2014-02-01

134

Effects of C60 fullerene nanoparticles on soil bacteria and protozoans.  

PubMed

Nanotechnology should produce numerous new materials in the coming years. Because of the novel design of nanomaterials with new physicochemical characteristics, their potential adverse impact on the environment and human health must be addressed. In the present study, agglomerates of pristine C60 fullerenes (50 nm to microm-size) were applied to soil at 0, 5, 25, and 50 mg/kg dry soil to assess their effect on the soil microbiota by measuring total respiration; biomass, number, and diversity of bacteria; and total number and diversity of protozoans during 14 d. Respiration and microbial biomass were unaffected by the fullerenes at any time, whereas the number of fast-growing bacteria was decreased by three- to fourfold just after incorporation of the nanomaterial. Protozoans seemed not to be very sensitive to C60, because their number decreased only slightly in the beginning of the experiment. With polymerase chain reaction and denaturing gradient gel electrophoresis analysis of eubacteria and kinetoplastids from the soil, however, a difference between the fullerene treatments and nonamended controls was demonstrated. The fullerenes did not induce more than 20 to 30% of relative dissimilarity (with both bacteria and protozoans) between treatments, but this effect was persistent throughout the experiment. It therefore is recommended that fullerene nanomaterial not be spread deliberately in the environment and that their ecotoxicology be further clarified. PMID:19086316

Johansen, Anders; Pedersen, Anette L; Jensen, Keld A; Karlson, Ulrich; Hansen, Bjarne M; Scott-Fordsmand, Janeck J; Winding, Anne

2008-09-01

135

Effect of hexavalent chromium on the activated sludge process and on the sludge protozoan community.  

PubMed

The objectives of this study were the determination of chromium effects to the performance of an activated sludge unit and the investigation of the response of the activated sludge protozoan community to Cr(VI). Two bench scale activated sludge reactors were supplied with synthetic sewage containing Cr(VI), at concentrations from 1 up to 50 mg L(-1). Protozoan species were identified and were related to the system efficiency. Variations in the abundance and diversity of the protozoan species were observed under various chromium concentrations. High removal rates of organics and nutrients were observed after the acclimatization of the activated sludge, which were related to the initial chromium(VI) concentration. Chromium(VI) removal efficiency was high in all cases. The protistan community was affected by the influent chromium content. Dominance of sessile species was observed in the reactor receiving 5 mg L(-1) influent chromium, whereas co-dominance of sessile and carnivorous species was observed in the reactors receiving higher chromium concentrations. PMID:18653331

Samaras, P; Papadimitriou, C A; Vavoulidou, D; Yiangou, M; Sakellaropoulos, G P

2009-01-01

136

Gap junction disappearance in astrocytes and leptomeningeal cells as a consequence of protozoan infection.  

PubMed

Trypanosoma cruzi and Toxoplasma gondii are protozoan parasites capable of causing infections of the nervous system. In order to determine effects of infection by these organisms on intercellular communication in the brain, dye coupling and connexin abundance and distribution were examined in leptomeningeal cells and astrocytes infected with T. cruzi or T. gondii. For both cell types infected with either type of protozoan parasite, intercellular diffusion of intracellularly injected Lucifer Yellow was dramatically reduced. Immunocytochemistry with antibodies specific for connexin43 (in astrocytes) or both connexin43 and connexin26 (for leptomeningeal cells) demonstrated that punctate gap junctional staining was much reduced in infected cells, although uninfected neighbors could display normal connexin abundance and distribution. Western blot analyses revealed that connexin43 abundance in both cell types infected with either parasite was similar to that in uninfected cells. Phosphorylation state of connexin43 (inferred from electrophoretic mobility of connexin43 isoforms) was not significantly affected by the infection process. Immunocytochemistry of whole brains from animals acutely infected with either parasite also showed a marked reduction in connexin43 expression. We conclude that infection of both types of brain cells with either protozoan parasite results in a loss of intercellular communication and organized gap junction plaques without affecting expression levels or posttranslational processing of gap junction proteins. Presumably, these changes in gap junction distribution result from altered targeting of the junctional protein to the plasma membrane, and/or from changes in assembly of subunits into functional channels. PMID:9593958

Campos de Carvalho, A C; Roy, C; Hertzberg, E L; Tanowitz, H B; Kessler, J A; Weiss, L M; Wittner, M; Dermietzel, R; Gao, Y; Spray, D C

1998-04-20

137

The Regulation of CD4+ T Cell Responses during Protozoan Infections  

PubMed Central

CD4+ T cells are critical for defense against protozoan parasites. Intracellular protozoan parasite infections generally require the development of a Th1 cell response, characterized by the production of IFN? and TNF that are critical for the generation of microbicidal molecules by phagocytes, as well as the expression of cytokines and cell surface molecules needed to generate cytolytic CD8+ T cells that can recognize and kill infected host cells. Over the past 25?years, much has been learnt about the molecular and cellular components necessary for the generation of Th1 cell responses, and it has become clear that these responses need to be tightly controlled to prevent disease. However, our understanding of the immunoregulatory mechanisms activated during infection is still not complete. Furthermore, it is apparent that although these mechanisms are critical to prevent inflammation, they can also promote parasite persistence and development of disease. Here, we review how CD4+ T cells are controlled during protozoan infections and how these regulatory mechanisms can influence parasite growth and disease outcome. PMID:25352846

Engwerda, Christian R.; Ng, Susanna S.; Bunn, Patrick T.

2014-01-01

138

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

PubMed Central

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

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

2009-01-01

139

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

PubMed Central

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

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

140

A new species of Caryospora Léger, 1904 (Apicomplexa: Eimeriidae) from the endangered Round Island boa Casarea dussumieri (Schlegel) (Serpentes: Bolyeridae) of Round Island, Mauritius: an endangered parasite?  

Microsoft Academic Search

A new species of Caryospora Léger, 1904 (Apicomplexa: Eimeriidae), C. durelli n. sp., is described from the endangered Round Island boa Casarea dussumieri (Schlegel) (Serpentes: Bolyeridae) from Round Island, Mauritius. Six of 11 hosts were infected. Oöcysts are spherical to\\u000a subspherical, 19.2 × 18.2 (17.5–21 × 16–21) ?m, n = 20, and have a shape index (mean length\\/mean width) of 1.05 (1.02–1.09).\\u000a The bi-layered wall is

Peter DaszakStanley; Stanley J. Ball; Daniel G. Streicker; Carl G. Jones; Keith R. Snow

2011-01-01

141

Revision of Geneiorhynchus Schneider, 1875 (Apicomplexa: Eugregarinida: Actinocephalidae: Acanthosporinae) with Recognition of Four New Species of Geneiorhynchus and Description of Geneiorhynchus manifestus n. sp. Parasitizing Naiads of the Green Darner, Anax junius (Odonata: Aeshnidae) in the Texas Big Thicket  

Microsoft Academic Search

Geneiorhynchus manifestus n. sp. (Apicomplexa: Eugregarinida) is described from the naiads of Anax junius (Odonata: Aeshnidae) collected from the Big Sandy Creek Unit of the Big Thicket National Preserve, Polk County, Texas, U.S.A. The genus Geneiorhynchus is revised and its constituent species reviewed. Descriptions are provided for 2 previously named species, Geneiorhynchus monnieri from naiads of Libellula depressa (Odonata: Libellulidae)

Richard E. Clopton; Tamara J. Cook; Jerry L. Cook

2007-01-01

142

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

PubMed Central

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 greater than 25 mg/liter in less than 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. PMID:3426216

Hoffman, R L; Atlas, R M

1987-01-01

143

Bioinformatic analysis of beta carbonic anhydrase sequences from protozoans and metazoans  

PubMed Central

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

2014-01-01

144

The Complete Mitochondrial Genome Sequence of Hepatozoon catesbianae (Apicomplexa: Coccidia: Adeleorina), a Blood Parasite of the Green Frog, Lithobates (Formerly Rana) clamitans.  

PubMed

A complete mitochondrial genome for the blood parasite Hepatozoon catesbianae (Alveolata; Apicomplexa; Coccidia; Adeleorina; Hepatozoidae) was obtained through PCR amplification and direct sequencing of resulting PCR products. The mitochondrial genome of H. catesbianae is 6,397 bp in length and contains 3 protein-coding genes (cytochrome c oxidase subunit I [COI]; cytochrome c oxidase subunit III [COIII]; and cytochrome B [CytB]). Sequence similarities to previously published mitochondrial genomes of other apicomplexan parasites permitted annotation of 23 putative rDNA fragments in the mitochondrial genome of H. catesbianae, 14 large subunit rDNA fragments, and 9 small subunit rDNA fragments. Sequences corresponding to rDNA fragments RNA5, RNA8, RNA11, and RNA19 of Plasmodium falciparum were not identified in the mitrochondrial genome sequence of H. catesbianae. Although the presence of 3 protein-coding regions and numerous putative rDNA fragments is a feature typical for apicomplexan mitochondrial genomes, the mitochondrial genome of H. catesbianae possesses a structure and gene organization that is distinct among the Apicomplexa. This is the first complete mitochondrial genome sequence obtained from any apicomplexan parasite in the suborder Adeleorina. PMID:24820055

Leveille, Alexandre N; Ogedengbe, Mosun E; Hafeez, Mian A; Tu, Hsiang-Hsien Abby; Barta, John R

2014-10-01

145

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

PubMed Central

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

de Dios Rosado, Juan; Rodriguez-Sosa, Miriam

2011-01-01

146

Trichodina xenopodus, a Ciliated Protozoan, in a Laboratory-Maintained Xenopus laevis  

PubMed Central

A postmortem evaluation of a domestically bred, adult, female Xenopus laevis revealed the presence of a urinary bladder protozoan consistent with Trichodina xenopodus. T. xenopodus is considered an incidental finding, as its presence in the urinary bladder in frogs has not been correlated with disease or with urinary bladder epithelial lesions. Trichodina spp. are ciliated protozoa known to colonize many species of amphibians and fish. These protozoa frequently inhabit the skin and gills, but may also be present in the urinary bladder of infected animals. Their presence on the skin and gills in low numbers is not related to disease; however, large numbers may indicate poor water quality and overcrowding. PMID:24209965

Collymore, Chereen; White, Julie R; Lieggi, Christine

2013-01-01

147

Trichodina xenopodus, a ciliated protozoan, in a laboratory-maintained Xenopus laevis.  

PubMed

A postmortem evaluation of a domestically bred, adult, female Xenopus laevis revealed the presence of a urinary bladder protozoan consistent with Trichodina xenopodus. T. xenopodus is considered an incidental finding, as its presence in the urinary bladder in frogs has not been correlated with disease or with urinary bladder epithelial lesions. Trichodina spp. are ciliated protozoa known to colonize many species of amphibians and fish. These protozoa frequently inhabit the skin and gills, but may also be present in the urinary bladder of infected animals. Their presence on the skin and gills in low numbers is not related to disease; however, large numbers may indicate poor water quality and overcrowding. PMID:24209965

Collymore, Chereen; White, Julie R; Lieggi, Christine

2013-08-01

148

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

PubMed

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

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

2013-10-01

149

The Deinococcus-Thermus phylum and the effect of rRNA composition on phylogenetic tree construction  

NASA Technical Reports Server (NTRS)

Through comparative analysis of 16S ribosomal RNA sequences, it can be shown that two seemingly dissimilar types of eubacteria Deinococcus and the ubiquitous hot spring organism Thermus are distantly but specifically related to one another. This confirms an earlier report based upon 16S rRNA oligonucleotide cataloging studies (Hensel et al., 1986). Their two lineages form a distinctive grouping within the eubacteria that deserved the taxonomic status of a phylum. The (partial) sequence of T. aquaticus rRNA appears relatively close to those of other thermophilic eubacteria. e.g. Thermotoga maritima and Thermomicrobium roseum. However, this closeness does not reflect a true evolutionary closeness; rather it is due to a "thermophilic convergence", the result of unusually high G+C composition in the rRNAs of thermophilic bacteria. Unless such compositional biases are taken into account, the branching order and root of phylogenetic trees can be incorrectly inferred.

Weisburg, W. G.; Giovannoni, S. J.; Woese, C. R.

1989-01-01

150

Evidence of Carbon Fixation Pathway in a Bacterium from Candidate Phylum SBR1093 Revealed with Genomic Analysis  

PubMed Central

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

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

2014-01-01

151

Unique posttranslational modifications in eukaryotic translation factors and their roles in protozoan parasite viability and pathogenesis.  

PubMed

Protozoan parasites are one of the major causes of diseases worldwide. The vector transmitted parasites exhibit complex life cycles involving interactions between humans, protozoa, and arthropods. In order to adapt themselves to the changing microenvironments, they have to undergo complex morphological and metabolic changes. These changes can be brought about by expressing a new pool of proteins in the cell or by modifying the existing repertoire of proteins via posttranslational modifications (PTMs). PTMs involve covalent modification and processing of proteins thereby modulating their functions. Some of these changes may involve PTMs of parasite proteins to help the parasite survive within the host and the vector. Out of many PTMs known, three are unique since they occur only on single proteins: ethanolamine phosphoglycerol (EPG) glutamate, hypusine and diphthamide. These modifications occur on eukaryotic elongation factor 1A (eEF1A), eukaryotic initiation factor 5A (eIF5A) and eukaryotic elongation factor 2 (eEF2), respectively. Interestingly, the proteins carrying these unique modifications are all involved in the elongation steps of translation. Here we review these unique PTMs, which are well conserved in protozoan parasites, and discuss their roles in viability and pathogenesis of parasites. Characterization of these modifications and studying their roles in physiology as well as pathogenesis will provide new insights in parasite biology, which may also help in developing new therapeutic interventions. PMID:23201129

Mittal, Nimisha; Subramanian, Gowri; Bütikofer, Peter; Madhubala, Rentala

2013-01-01

152

Crystal structures and proposed structural/functional classification of three protozoan proteins from the isochorismatase superfamily  

PubMed Central

We have determined the crystal structures of three homologous proteins from the pathogenic protozoans Leishmania donovani, Leishmania major, and Trypanosoma cruzi. We propose that these proteins represent a new subfamily within the isochorismatase superfamily (CDD classification cd004310). Their overall fold and key active site residues are structurally homologous both to the biochemically well-characterized N-carbamoylsarcosine-amidohydrolase, a cysteine hydrolase, and to the phenazine biosynthesis protein PHZD (isochorismase), an aspartyl hydrolase. All three proteins are annotated as mitochondrial-associated ribonuclease Mar1, based on a previous characterization of the homologous protein from L. tarentolae. This would constitute a new enzymatic activity for this structural superfamily, but this is not strongly supported by the observed structures. In these protozoan proteins, the extended active site is formed by inter-subunit association within a tetramer, which implies a distinct evolutionary history and substrate specificity from the previously characterized members of the isochorismatase superfamily. The characterization of the active site is supported crystallographically by the presence of an unidentified ligand bound at the active site cysteine of the T. cruzi structure. PMID:16199669

Caruthers, Jonathan; Zucker, Frank; Worthey, Elizabeth; Myler, Peter J.; Buckner, Fred; Van Voorhuis, Wes; Mehlin, Chris; Boni, Erica; Feist, Tiffany; Luft, Joseph; Gulde, Stacey; Lauricella, Angela; Kaluzhniy, Oleksandr; Anderson, Lori; Le Trong, Isolde; Holmes, Margaret A.; Earnest, Thomas; Soltis, Michael; Hodgson, Keith O.; Hol, Wim G.J.; Merritt, Ethan A.

2005-01-01

153

Recurrent wheezing is associated with intestinal protozoan infections in Warao Amerindian children in Venezuela: a cross-sectional survey  

PubMed Central

Background While in developed countries the prevalence of allergic diseases is rising, inflammatory diseases are relatively uncommon in rural developing areas. High prevalence rates of helminth and protozoan infections are commonly found in children living in rural settings and several studies suggest an inverse association between helminth infections and allergies. No studies investigating the relationship between parasitic infections and atopic diseases in rural children of developing countries under the age of 2 years have been published so far. We performed a cross-sectional survey to investigate the association of helminth and protozoan infections and malnutrition with recurrent wheezing and atopic eczema in Warao Amerindian children in Venezuela. Methods From August to November 2012, 229 children aged 0 to 2 years residing in the Orinoco Delta in Venezuela were enrolled. Data were collected through standardized questionnaires and physical examination, including inspection of the skin and anthropometric measurements. A stool sample was requested from all participants and detection of different parasites was performed using microscopy and real time polymerase chain reaction (PCR). Results We observed high prevalence rates of atopic eczema and recurrent wheezing, respectively 19% and 23%. The prevalence of helminth infections was 26% and the prevalence of protozoan infections was 59%. Atopic eczema and recurrent wheezing were more frequently observed in stunted compared with non-stunted children in multivariable analysis (OR 4.3, 95% CI 1.3 – 13.6, p?=?0.015 and OR 4.5, 95% CI 0.97 – 21.2, p?=?0.055). Furthermore, recurrent wheezing was significantly more often observed in children with protozoan infections than in children without protozoan infections (OR 6.7, 95% CI 1.5 – 30.5). Conclusions High prevalence rates of atopic eczema and recurrent wheezing in Warao Amerindian children under 2 years of age were related to stunting and intestinal protozoan infections respectively. Helminth infections were not significantly associated with either atopic eczema or recurrent wheezing. PMID:24885094

2014-01-01

154

Prevalence and pathology of the nematode Heterakis gallinarum, the trematode Paratanaisia bragai, and the protozoan Histomonas meleagridis in the turkey, Meleagris gallopavo  

Microsoft Academic Search

The prevalence of infection and associated pathology induced by two helminth and one protozoan species infecting Brazilian turkeys are reported. The intestinal nematode Heterakis gallinarum appeared with a prevalence of 70% in the infected birds, without gross lesions when not associated to the protozoan Histomonas meleagridis. Histological findings in the ceca were represented by the presence of H. gallinarum worms,

Beatriz Brener; Rogério Tortelly; Rodrigo Caldas Menezes; Luís C Muniz-Pereira; Roberto Magalhães Pinto

2006-01-01

155

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

PubMed

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

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

2013-12-01

156

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

PubMed

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

Zhokhov, A E; Pugacheva, M N

2012-01-01

157

Proteasome activity is required for the stage-specific transformation of a protozoan parasite  

PubMed Central

A prominent feature of the life cycle of intracellular parasites is the profound morphological changes they undergo during development in the vertebrate and invertebrate hosts. In eukaryotic cells, most cytoplasmic proteins are degraded in proteasomes. Here, we show that the transformation in axenic medium of trypomastigotes of Trypanosoma cruzi into amastigote-like organisms, and the intracellular development of the parasite from amastigotes into trypomastigotes, are prevented by lactacystin, or by a peptide aldehyde that inhibits proteasome function. Clasto-lactacystin, an inactive analogue of lactacystin, and cell-permeant peptide aldehyde inhibitors of T. cruzi cysteine proteinases have no effect. We have also identified the 20S proteasomes from T. cruzi as a target of lactacystin in vivo. Our results document the essential role of proteasomes in the stage-specific transformation of a protozoan. PMID:8920878

1996-01-01

158

Identification of developmentally regulated genes in Entamoeba histolytica: insights into mechanisms of stage conversion in a protozoan parasite  

Microsoft Academic Search

Summary Developmental switching between life-cycle stages is a common feature among many pathogenic organisms. The protozoan parasite Entamoeba his- tolytica converts between cysts (essential for disease transmission) and trophozoites (responsible for tissue invasion). Identification of genes involved in the developmental pathway has been severely hindered by the inability to generate E. histolytica cysts in vitro. Using parasite strains derived from

Gretchen M. Ehrenkaufer; Rashidul Haque; Jason A. Hackney; Daniel J. Eichinger; Upinder Singh

2007-01-01

159

Growth of the protozoan parasite Entamoeba histolytica in 5-azacytidine has limited effects on parasite gene expression  

Microsoft Academic Search

BACKGROUND: In higher eukaryotes DNA methylation regulates important biological functions including silencing of gene expression and protection from adverse effects of retrotransposons. In the protozoan parasite Entamoeba histolytica, a DNA methyltransferase has been identified and treatment with 5-azacytidine (5-AzaC), a potent inhibitor of DNA methyltransferase, has been reported to attenuate parasite virulence. However, the overall extent of DNA methylation and

Ibne Karim M Ali; Gretchen M Ehrenkaufer; Jason A Hackney; Upinder Singh

2007-01-01

160

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

E-print Network

parasite that infects most species of warm blooded animals, including humans, and can cause the disease-to-person, except in instances of mother-to-child (congenital) transmission and blood transfusion or organToxoplasmosis Toxoplasma gondii is a protozoan parasite that can infect many animals, including

Wood, Marcelo A.

161

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

PubMed Central

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, USA, acetate amendments initially promoted the growth of metal-reducing Geobacter species, followed by the growth of sulfate reducers, as observed previously. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater before the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the ameboid 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. PMID:23446832

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

2013-01-01

162

A new species of Caryospora Léger, 1904 (Apicomplexa: Eimeriidae) from the snake Philodryas olfersii Lichtenstein (Colubridae) from a coastal habitat in Brazil.  

PubMed

A new coccidian species of the genus Caryospora Léger, 1904 (Protozoa, Apicomplexa, Eimeriidae) is reported from the colubrid snake host Philodryas olfersii Lichtenstein at a coastal area in the State of Rio de Janeiro, south-eastern Brazil. Oöcysts of Caryospora olfersii n. sp. are spherical to sub-spherical, 33.1 × 31.2 ?m, with smooth, colourless, three-layered wall, c.1.4; middle layer lightly striated. Micropyle, oöcyst residuum and polar granule are all absent. Sporocysts are ovoid, 22.9 × 17.4 ?m on average, with one extremity in the shape of a short neck. Stieda body present, 3.2 × 1.3 ?m, sub-Stieda body present, homogeneous, larger than Stieda body, 4.5 × 1.7 ?m. Sporozoites are inserted in a bulky sporocyst residuum. PMID:23673697

Viana, Lúcio A; Winck, Gisele R; Coelho, Cleide D; Flausino, Walter; Duarte Rocha, Carlos F

2013-06-01

163

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

PubMed

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

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

2005-08-01

164

Factors Associated with High Prevalence of Intestinal Protozoan Infections among Patients in Sana'a City, Yemen  

PubMed Central

Background Intestinal protozoan diseases in Yemen are a significant health problem with prevalence ranging from 18% to 27%. The present study is a cross-sectional study aimed at determining the factors associated with the high prevalence of intestinal protozoan infections among patients seeking health care in Sana'a City, the capital of Yemen. Methodology/Principal Findings Stool samples were collected from 503 patients aged between 1 and 80 years old; 219 were males and 284 females. Biodata were collected via pretested standard questionnaire. Faecal samples were processed and examined for (oo)cysts or ova using a wet mount preparation after formal-ether concentration technique. Cryptosporidium oocysts were detected using the Ziehl-Neelsen staining technique. The overall prevalence of intestinal protozoan infections was 30.9%. Infection rates of Giardia duodenalis, Entamoeba histolytica/dispar and Cryptosporidium were 17.7%, 17.1% and 1%, respectively. Other parasites detected included Ascaris lumbricoides (2.4%), Schistosoma mansoni (0.3%), Hymenolepis nana (1.4%) and Enterobius vermicularis (0.4%). Multivariate analysis using forward stepwise logistic regression based on intestinal protozoan infections showed that contact with animals (OR?=?1.748, 95% CI?=?1.168–2.617) and taking bath less than twice a week (OR?=?1.820, 95% CI?=?1.192–2.779) were significant risk factors of protozoan infections. Conclusions/Significance This present study indicated that intestinal protozoan infections are still a public health problem in Yemen, with Giardia and Entamoeba infections being most common. Statistical analysis indicated that low personal hygiene and contact with animals were important predictors for intestinal protozoan infections. As highlighted in this study, in order to effectively reduce these infections, a multi-sectoral effort is needed. Preventive measures should include good hygienic practices, good animal husbandry practices, heightened provision of educational health programs, health services in all governorates including rural areas. Furthermore, it is also essential to find radical solutions to the recent water crises in Yemen. PMID:21789210

Alyousefi, Naelah A.; Mahdy, Mohammed A. K.; Mahmud, Rohela; Lim, Yvonne A. L.

2011-01-01

165

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

SciTech Connect

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 indicate that the replicate assemblies represent a new phylum-level lineage referred to here as '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 CO dehydrogenase complex likely used for energy conservation. Moreover, this novel population contains genes involved in 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 mats of YNP, and will provide insight regarding the evolution of Archaea in early Earth environments that may have important analogues active in YNP today.

Kozubal, Mark; Romine, Margaret F.; Jennings, Ryan; Jay, Z.; Tringe, Susannah G.; Rusch, Douglas B.; Beam, Jake; McCue, Lee Ann; Inskeep, William P.

2013-03-01

166

Pyramidobacter piscolens gen. nov., sp. nov., a member of the phylum 'Synergistetes' isolated from the human oral cavity  

PubMed Central

Four strains of anaerobic, Gram-negative bacilli isolated from the human oral cavity were subjected to a comprehensive range of phenotypic and genotypic tests and were found to comprise a homogeneous group distinct from any species with validly published names. 16S rRNA and 23S rRNA gene sequence analyses and DNA–DNA reassociation data revealed that the strains constituted a novel group within the phylum ‘Synergistetes’ and were most closely related to Jonquetella anthropi. Two libraries of randomly cloned DNA were prepared from strain W5455T and were sequenced to provide a genome survey as a resource for metagenomic studies. A new genus and novel species, Pyramidobacter piscolens gen. nov., sp. nov., is proposed to accommodate these strains. The genus Pyramidobacter comprises strains that are anaerobic, non-motile, asaccharolytic bacilli that produce acetic and isovaleric acids and minor to trace amounts of propionic, isobutyric, succinic and phenylacetic acids as end products of metabolism. P. piscolens gen. nov., sp. nov. produced hydrogen sulphide but was otherwise largely biochemically unreactive. Growth was stimulated by the addition of glycine to broth media. The G+C content of the DNA of the type strain was 59?mol%. The type strain of Pyramidobacter piscolens sp. nov. is W5455T (=DSM 21147T=CCUG 55836T). PMID:19406777

Downes, Julia; Vartoukian, Sonia R.; Dewhirst, Floyd E.; Izard, Jacques; Chen, Tsute; Yu, Wen-Han; Sutcliffe, Iain C.; Wade, William G.

2009-01-01

167

Characterization of a new marine nitrite oxidizing bacterium, Nitrospina watsonii sp. nov., a member of the newly proposed phylum "Nitrospinae".  

PubMed

Nitrite oxidizing bacteria are an integral part of the nitrogen cycle in marine waters, but the knowledge about their diversity is limited. Recently, a high abundance of Nitrospina-like 16S rRNA gene sequences has been detected in oceanic habitats with low oxygen content by molecular methods. Here, we describe a new strain of Nitrospina, which was sampled in 100m depth from the Black Sea. It coexisted with a not-yet cultivated chemoorganotrophic gammaproteobacterium and could be purified by classical isolation methods including Percoll density gradient centrifugation. The new Nitrospina-like bacterium grew lithoautotrophically at 28°C in diluted seawater supplemented with inorganic salts and nitrite. Gram-negative rods were characterized morphologically, physiologically and partly biochemically. The 16S rRNA gene of the new strain of Nitrospina is 97.9% similar to the described species N. gracilis and DNA/DNA hybridization experiments revealed a relatedness of 30.0%. The data from both Nitrospina species and environmental clones were used for an extensive 16S rRNA based phylogenetic study applying high quality filtering. Treeing analyses confirm the newly defined phylum status for "Nitrospinae" [18]. The results of phylogenetic and genotypic analyses support the proposal of a novel species Nitrospina watsonii sp. nov. (type strain 347(T), LMG 27401(T), NCIMB 14887(T)). PMID:24581679

Spieck, Eva; Keuter, Sabine; Wenzel, Thilo; Bock, Eberhard; Ludwig, Wolfgang

2014-05-01

168

Seasonal dominance of CL500-11 bacterioplankton (phylum Chloroflexi) in the oxygenated hypolimnion of Lake Biwa, Japan.  

PubMed

Uncultured bacteria affiliated with the CL500-11 cluster (phylum Chloroflexi) were first reported from the oxygenated hypolimnion of Crater Lake (USA) as a predominant bacterioplankton, although this dominance has not been reported in other environments. In this study, we showed that CL500-11 is also dominant in the oxygenated hypolimnion of Lake Biwa (Japan) and followed its spatiotemporal succession using fluorescent in situ hybridization. CL500-11 cells were almost absent [< 1% of 4',6-diamidino-2-phenylindole (DAPI)-stained cells] at the beginning of the stratification period, dominated (> 10% of DAPI-stained cells; maximum = 16.5%) in the hypolimnion during the stratification period, and decreased to below the detection limit with the collapse of the thermocline. This pattern was observed over two annual cycles. A longitudinal assessment also showed that CL500-11 was the dominant bacterium in the hypolimnion over the whole lake, but was generally undetectable in the stratified epilimnion. These data suggest that CL500-11 is acclimated to the oxygenated hypolimnion and is a potentially important component of the pelagic biogeochemical cycling of the lake. A comparative analysis of 16S rRNA gene sequences revealed that almost all CL500-11 sequences previously deposited in the database were detected from hypolimnion or holomictic water in deep oxic freshwater lakes, suggesting that the bacteria may form one of the common lineages residing in an aerobic hypolimnetic niche. PMID:22809435

Okazaki, Yusuke; Hodoki, Yoshikuni; Nakano, Shin-ichi

2013-01-01

169

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

PubMed Central

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

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

170

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

PubMed

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

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

2013-03-01

171

Chthoniobacter flavus gen. nov., sp. nov., the first pure-culture representative of subdivision two, spartobacteria classis nov., of the phylum verrucomicrobia  

Microsoft Academic Search

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

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

2004-01-01

172

Screening of antiangiogenic potential of twenty two marine invertebrate extracts of phylum Mollusca from South East Coast of India  

PubMed Central

Objective To evaluate the antiangiogenic potential of twenty two marine invertebrate species of Phylum Mollusca from south east coast of India. Methods Live specimens of molluscan species were collected and their methanolic extracts were evaluated for preliminary antiangiogenic activity using the in ovo chick chorio-allantoic membrane assay. The extracts were further evaluated for in vivo antiangiogenic activity using chemical cautery induced corneal neovascularization assay in rats and oxygen induced retinopathy assay in rat pups. Results In the chick chorio-allantoic membrane assay, four methanolic extracts of marine molluscan species viz. Meretrix meretrix, Meretrix casta, Telescopium telescopium and Bursa crumena methanolic extracts exhibited noticeable antiangiogenic activity at the tested concentration of 200 µg whereby they significantly inhibited the VEGF induced proliferation of new blood vessels. Among these four extracts, the methanolic extract of Meretrix casta exhibited relatively higher degree of antiangiogenic activity with an inhibitiory percentage (64.63%) of the VEGF induced neovascularization followed by the methanolic extracts of Telescopium telescopium (62.02%), Bursa crumena (60.48%) and Meretrix meretrix (47.01%). These four methanolic extracts were further evaluated for in vivo antiangiogenic activity whereby the methanolic extract of Telescopium telescopium exhibited most noticeable inhibition (42.58%) of the corneal neovascularization in rats in comparison to the sham treated group, and also exhibited most noticeable inhibition (31.31%) of the oxygen induced retinal neovascularization in rat pups in comparison to the hyperoxia group that was observed for considerable retinal neovascularization. Conclusions The significant antiangiogenic activity evinced by the extract of Telescopium telescopium merits further investigation for ocular neovascular diseases. PMID:25183067

Gupta, Pankaj; Arumugam, Muthuvel; Azad, Raj Vardhan; Saxena, Rohit; Ghose, Supriyo; Biswas, Nihar Ranjan; Velpandian, Thirumurthy

2014-01-01

173

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

PubMed

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

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

2011-01-01

174

Community genomic analyses constrain the distribution of metabolic traits across the Chloroflexi phylum and indicate roles in sediment carbon cycling  

PubMed Central

Background Sediments are massive reservoirs of carbon compounds and host a large fraction of microbial life. Microorganisms within terrestrial aquifer sediments control buried organic carbon turnover, degrade organic contaminants, and impact drinking water quality. Recent 16S rRNA gene profiling indicates that members of the bacterial phylum Chloroflexi are common in sediment. Only the role of the class Dehalococcoidia, which degrade halogenated solvents, is well understood. Genomic sampling is available for only six of the approximate 30 Chloroflexi classes, so little is known about the phylogenetic distribution of reductive dehalogenation or about the broader metabolic characteristics of Chloroflexi in sediment. Results We used metagenomics to directly evaluate the metabolic potential and diversity of Chloroflexi in aquifer sediments. We sampled genomic sequence from 86 Chloroflexi representing 15 distinct lineages, including members of eight classes previously characterized only by 16S rRNA sequences. Unlike in the Dehalococcoidia, genes for organohalide respiration are rare within the Chloroflexi genomes sampled here. Near-complete genomes were reconstructed for three Chloroflexi. One, a member of an unsequenced lineage in the Anaerolinea, is an aerobe with the potential for respiring diverse carbon compounds. The others represent two genomically unsampled classes sibling to the Dehalococcoidia, and are anaerobes likely involved in sugar and plant-derived-compound degradation to acetate. Both fix CO2 via the Wood-Ljungdahl pathway, a pathway not previously documented in Chloroflexi. The genomes each encode unique traits apparently acquired from Archaea, including mechanisms of motility and ATP synthesis. Conclusions Chloroflexi in the aquifer sediments are abundant and highly diverse. Genomic analyses provide new evolutionary boundaries for obligate organohalide respiration. We expand the potential roles of Chloroflexi in sediment carbon cycling beyond organohalide respiration to include respiration of sugars, fermentation, CO2 fixation, and acetogenesis with ATP formation by substrate-level phosphorylation. PMID:24450983

2013-01-01

175

Comparing the tolerance limits of selected bacterial and protozoan species to nickel in wastewater systems.  

PubMed

Heavy-metal resistant microorganisms play a significant role in the treatment of industrial wastewater. The detoxifying ability of these resistant microorganisms can be manipulated for bioremediation of heavy metals in wastewater systems. This study aimed at comparing the tolerance limit of selected wastewater protozoan species (Aspidisca sp., Trachelophyllum sp. and Peranema sp.) against Ni(2+) with that of selected bacterial species (Bacillus licheniformis-ATCC12759, Brevibacillus laterosporus-ATCC64 and Pseudomonas putida-ATCC31483) commonly found in wastewater systems. The isolates were exposed to various concentrations of Ni(2+) in mixed liquor and their tolerance to Ni(2+) assessed at different temperatures (25°C, 30°C, 35°C and 40°C) and pHs (4, 6, 7, 8 and 10). The physicochemical parameters such as chemical oxygen demand (COD) and dissolved oxygen (DO) of the media and the growth rates of the isolates were measured using standard methods. In terms of their minimum inhibitory concentrations (MIC), the results revealed that the isolates could tolerate Ni(2+) at concentrations ranging between 32 and 52ppm for protozoa and between 52 and 84ppm for bacteria. B. licheniformis-ATCC12759 was the most tolerant bacterial species (MIC: 84ppm-Ni(2+)) while Peranema sp. was the most tolerant protozoan species (MIC: 52ppm-Ni(2+)). At 10 and/or 20ppm-Ni(2+) the growth of B. licheniformis-ATCC12759 (6.30 days(-1) for 10 and 5.73 days(-1) for 20ppm-Ni(2+)), P. putida-ATCC31483 (6.02 days(-1) for 10 and 5.31 days(-1) for 20ppm-Ni(2+)) and Peranema sp. (2.15 days(-1) for 10ppm-Ni(2+)) was stimulated after one day of incubation. Statistical evidence showed significant differences (p=0.0065) between the MIC of the six isolates and positive correlations between COD and the growth rates of isolates (r=0.8999/0.8810 for bacteria/protozoa). The tolerance limit of all isolates was significantly dependent on the pH and the temperature. The study suggests that these isolates can be used for the bioremediation of nickel in industrial wastewater systems. PMID:22014510

Kamika, I; Momba, M N B

2011-12-01

176

Toxoplasma gondii infection in humans in China  

PubMed Central

Toxoplasmosis is a zoonotic infection of humans and animals, caused by the opportunistic protozoan Toxoplasma gondii, a parasite belonging to the phylum Apicomplexa. Infection in pregnant women may lead to abortion, stillbirth or other serious consequences in newborns. Infection in immunocompromised patients can be fatal if not treated. On average, one third of people are chronically infected worldwide. Although very limited information from China has been published in the English journals, T. gondii infection is actually a significant human health problem in China. In the present article, we reviewed the clinical features, transmission, prevalence of T. gondii infection in humans in China, and summarized genetic characterizations of reported T. gondii isolates. Educating the public about the risks associated with unhealthy food and life style habits, tracking serological examinations to special populations, and measures to strengthen food and occupational safety are discussed. PMID:21864327

2011-01-01

177

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

PubMed Central

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

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

1990-01-01

178

Phylum Cnidaria Introduction  

E-print Network

with radially distributed sense organs Neurons serve sensory and motor systems. Epithelial layer of a cnidarian cnidaria (sea anemones and jellyfish) may have two nerve nets. Slow conducting network Fine fibers end cells beneath epithelium Bigger fibers, faster conduction of impulse Enables major responses

Cochran-Stafira, D. Liane

179

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

PubMed

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

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

2014-07-01

180

Autophagy during Proliferation and Encystation in the Protozoan Parasite Entamoeba invadens?  

PubMed Central

Autophagy is one of the three systems responsible for the degradation of cytosolic proteins and organelles. Autophagy has been implicated in the stress response to starvation, antigen cross-presentation, the defense against invading bacteria and viruses, differentiation, and development. Saccharomyces cerevisiae Atg8 and its mammalian ortholog, LC3, play an essential role in autophagy. The intestinal protozoan parasite Entamoeba histolytica and a related reptilian species, Entamoeba invadens, possess the Atg8 conjugation system, consisting of Atg8, Atg4, Atg3, and Atg7, but lack the Atg5-to-Atg12 conjugation system. Immunofluorescence imaging revealed that polymorphic Atg8-associated structures emerged in the logarithmic growth phase and decreased in the stationary phase and also increased in the early phase of encystation in E. invadens. Immunoblot analysis showed that the increase in phosphatidylethanolamine-conjugated membrane-associated Atg8 was also accompanied by the emergence of Atg8-associated structures during the proliferation and differentiation mentioned above. Specific inhibitors of class I and III phosphatidylinositol 3-kinases simultaneously inhibited both the growth of trophozoites and autophagy and also both encystation and autophagy in E. invadens. These results suggest that the core machinery for autophagy is conserved and plays an important role during proliferation and differentiation in Entamoeba. PMID:17923513

Picazarri, Karina; Nakada-Tsukui, Kumiko; Nozaki, Tomoyoshi

2008-01-01

181

Protozoan ALKBH8 Oxygenases Display both DNA Repair and tRNA Modification Activities  

PubMed Central

The ALKBH family of Fe(II) and 2-oxoglutarate dependent oxygenases comprises enzymes that display sequence homology to AlkB from E. coli, a DNA repair enzyme that uses an oxidative mechanism to dealkylate methyl and etheno adducts on the nucleobases. Humans have nine different ALKBH proteins, ALKBH1–8 and FTO. Mammalian and plant ALKBH8 are tRNA hydroxylases targeting 5-methoxycarbonylmethyl-modified uridine (mcm5U) at the wobble position of tRNAGly(UCC). In contrast, the genomes of some bacteria encode a protein with strong sequence homology to ALKBH8, and robust DNA repair activity was previously demonstrated for one such protein. To further explore this apparent functional duality of the ALKBH8 proteins, we have here enzymatically characterized a panel of such proteins, originating from bacteria, protozoa and mimivirus. All the enzymes showed DNA repair activity in vitro, but, interestingly, two protozoan ALKBH8s also catalyzed wobble uridine modification of tRNA, thus displaying a dual in vitro activity. Also, we found the modification status of tRNAGly(UCC) to be unaltered in an ALKBH8 deficient mutant of Agrobacterium tumefaciens, indicating that bacterial ALKBH8s have a function different from that of their eukaryotic counterparts. The present study provides new insights on the function and evolution of the ALKBH8 family of proteins. PMID:24914785

Zdzalik, Daria; Vagb?, Cathrine B.; Kirpekar, Finn; Davydova, Erna; Puscian, Alicja; Maciejewska, Agnieszka M.; Krokan, Hans E.; Klungland, Arne; Tudek, Barbara; van den Born, Erwin; Falnes, Pal ?.

2014-01-01

182

[Prevalence of protozoans helminths among cats purchased for experimental use in the Kanto Area].  

PubMed

Prevalence of protozoan and helminth parasites in adult cats for experimental use obtained from Kanto area, Japan during the period of 1973-74 (91 cats) and 1980-81 (80 cats) was investigated by means of autopsy, fecal examination and serological tests. No protozoa were found in blood smear specimens. The rate of positive Toxoplasma antibody tests was 65.4% (hemagglutination test) in 1973-74 and 26.3% (latex agglutination test) in 1980-81. Oocysts of coccidia found in feces were Isospora felis and I. rivolta. In the intestine of 63.7% (1980-81) and 69.2% (1973-74) of the cats, one or more species of helminth parasites were found. The helminth parasites found in the intestine were Toxocara cati, Ancylostoma tubaeforme, Taenia taeniaeformis, Dipylidium caninum, Spirometra erinacei and Pharyngostomum cordatum. Physaloptera sp., Dirofilaria immitis, Clonorchis sinensis and Capillaria plica were found in the stomach, heart, bile duct and urinary bladder, respectively. Differences between the results in 1973-74 and that in 1980-81 were discussed. PMID:6653679

Fujinami, F; Tanaka, H; Ohshima, S

1983-07-01

183

A rhodopsin immunoanalog in the related photosensitive protozoans Blepharisma japonicum and Stentor coeruleus.  

PubMed

Immunoblotting of isolated cell membrane fractions from ciliates Blepharisma japonicum and Stentor coeruleus with a polyclonal antibody raised against rhodopsin revealed one strong protein band of about 36 kDa, thought to correspond to protozoan rhodopsin. Inspection of both ciliates labeled with the same antibody using a confocal microscope confirmed the immunoblotting result and demonstrated the presence of these rhodopsin-like molecules localized within the cell membrane area. Immunoblot analysis of the ciliate membrane fractions resolved by two-dimensional gel electrophoresis identified two distinct 36 kDa spots at pIs of 4.5 and 7.0 for Blepharisma, and three spots at pIs of 4.4, 5.0 and 6.0 for Stentor, indicating a possible mixture of phosphorylated rhodopsin species in these cells. The obtained results suggest that both Blepharisma and the related ciliate Stentor contain within the cell membrane the rhodopsin-like proteins, which may be involved as receptor molecules in the sensory transduction pathway mediating motile photoresponses in these protists as in other species of lower eukaryota. PMID:18754050

Fabczak, Hanna; Sobierajska, Katarzyna; Fabczak, Stanis?aw

2008-09-01

184

Phototaxis in the ciliated protozoan Ophryoglena flava: dose-effect curves and action spectrum determination.  

PubMed

The sensitivity of positive phototactic orientation of cells of the ciliated protozoan Ophryoglena flava has been measured for white light, broad-band blue and red light, and narrow-band monochromatic light, using a laboratory-developed computer aided system. The white-light fluence rate-response curve shows that there is no negative phototaxis in the fluence rate range investigated (0-15 W/m2) and no adaptation phenomena; it is very well fitted by a hyperbolic function; the fluence rate curves under broad band blue and red light (full width at half maximum, FWHM= 100 nm) can be fitted by the same model. The saturation level is, within experimental errors, the same for the three curves, indicating that there are no chromaticity effects and that if there is more than one photoreceptor pigment, they act independently of each other. The fluence rate-response curves determined under narrow band monochromatic light (FWHM = 10 nm) can also be fitted by the same model and show, within experimental errors, the same saturation level. An action spectrum for positive phototaxis at 10-nm intervals has been calculated from fluence rate-response curves: it shows three maxima, at 420, 540 and 590 nm. This action spectrum is significantly different from the ones for photomotile responses in Blepharisma japonicum, Stentor coeruleus and Chlamydodon mnemosyne, whereas it resembles the ones of Paramecium bursaria and Fabrea salina. PMID:11100836

Cadetti, L; Marroni, F; Marangoni, R; Kuhlmann, H W; Gioffré, D; Colombetti, G

2000-08-01

185

Identification and characterization of the arsenite methyltransferase from a protozoan, Tetrahymena pyriformis.  

PubMed

Arsenic (As) methylation in aquatic microbes plays a major role in the biogeochemistry of As. Protozoa, especially the free-living freshwater species, are important players in aquatic ecological health. In this study, an arsenite (As(III)) methyltransferase, TpyArsM, was identified and characterized in a free-living protozoan, Tetrahymena pyriformis. In order to confirm its function, TpyarsM gene was knocked-out in Tetrahymena and was also heterologously expressed in hypersensitive E. coli; these events resulted in expected decreases in As tolerance and methylation ability, respectively. In-vitro tests revealed that purified TpyArsM protein methylated inorganic As to mono- and di- methylarsenate, and also had the novel property of producing trimethylarsenite (TMA(III)) and dimethylarsine (Me2AsH) gases. This new methyltransferase gene, identified in a species near the base of the food web, has enriched our knowledge of As methyltransferases and has great potential for bioremediation of As-contaminated environments. PMID:24561426

Ye, Jun; Chang, Yue; Yan, Yu; Xiong, Jie; Xue, Xi-Mei; Yuan, Dongxia; Sun, Guo-Xin; Zhu, Yong-Guan; Miao, Wei

2014-04-01

186

The first suicides: a legacy inherited by parasitic protozoans from prokaryote ancestors  

PubMed Central

It is more than 25 years since the first report that a protozoan parasite could die by a process resulting in a morphological phenotype akin to apoptosis. Since then these phenotypes have been observed in many unicellular parasites, including trypanosomatids and apicomplexans, and experimental evidence concerning the molecular pathways that are involved is growing. These observations support the view that this form of programmed cell death is an ancient one that predates the evolution of multicellularity. Here we review various hypotheses that attempt to explain the origin of apoptosis, and look for support for these hypotheses amongst the parasitic protists as, with the exception of yeast, most of the work on death mechanisms in unicellular organisms has focussed on them. We examine the role that addiction modules may have played in the original eukaryote cell and the part played by mitochondria in the execution of present day cells, looking for examples from Leishmania spp. Trypanosoma spp. and Plasmodium spp. In addition, the expanding knowledge of proteases, nucleases and other molecules acting in protist execution pathways has enabled comparisons to be made with extant Archaea and bacteria and with biochemical pathways that evolved in metazoans. These comparisons lend support to the original sin hypothesis but also suggest that present-day death pathways may have had multifaceted beginnings. PMID:23597031

2013-01-01

187

Global Distribution, Public Health and Clinical Impact of the Protozoan Pathogen Cryptosporidium  

PubMed Central

Cryptosporidium spp. are coccidians, oocysts-forming apicomplexan protozoa, which complete their life cycle both in humans and animals, through zoonotic and anthroponotic transmission, causing cryptosporidiosis. The global burden of this disease is still underascertained, due to a conundrum transmission modality, only partially unveiled, and on a plethora of detection systems still inadequate or only partially applied for worldwide surveillance. In children, cryptosporidiosis encumber is even less recorded and often misidentified due to physiological reasons such as early-age unpaired immunological response. Furthermore, malnutrition in underdeveloped countries or clinical underestimation of protozoan etiology in developed countries contribute to the underestimation of the worldwide burden. Principal key indicators of the parasite distribution were associated to environmental (e.g., geographic and temporal clusters, etc.) and host determinants of the infection (e.g., age, immunological status, travels, community behaviours). The distribution was geographically mapped to provide an updated picture of the global parasite ecosystems. The present paper aims to provide, by a critical analysis of existing literature, a link between observational epidemiological records and new insights on public health, and diagnostic and clinical impact of cryptosporidiosis. PMID:20706669

Putignani, Lorenza; Menichella, Donato

2010-01-01

188

The effects of different silage additives on rumen protozoan number and volatile fatty acid concentration in sheep fed corn silage  

Microsoft Academic Search

The main objective of this study was to determine the effects of different silage additives on protozoan population, genera and total volatile fatty acid (VFA) concentrations and percentage of VFAs in corn silage. Four ruminally fistulated Morkaraman×K?v?rc?k lambs were used in a 4×4 Latin square design with 14-day adaptation and 1-day sampling periods. The animals were offered 20% cottonseed meal

N Dönmez; M. A Karsl?; A Ç?nar; T Aksu; E Baytok

2003-01-01

189

Incidence and Persistence of Zoonotic Bacterial and Protozoan Pathogens in a Beef Cattle Feedlot Runoff Control–Vegetative Treatment System  

Microsoft Academic Search

Determining the survival of zoonotic pathogens in livestock manure and runoff is critical for understanding the environmental and public health risks associated with these wastes. Th e occurrence and persistence of the bacterial pathogens Escherichia coli O157:H7 and Campylobacter spp. in a passive beef cattle feedlot runoff control-vegetative treatment system were examined over a 26-mo period. Incidence of the protozoans

Elaine D. Berry; Bryan L. Woodbury; John A. Nienaber; Roger A. Eigenberg; Jeanette A. Thurston; James E. Wells

2007-01-01

190

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

Microsoft Academic Search

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

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

1998-01-01

191

[Protozoans in superficial waters and faecal samples of individuals of rural populations of the Montes municipality, Sucre state, Venezuela].  

PubMed

In Sucre state, the Manzanares river is threatened by domestic, agricultural and industrial activities, becoming an environmental risk factor for its inhabitants. In this sense, the presence of protozoans in superficial waters of tributaries of the Manzanares river (Orinoco river, Quebrada Seca, San Juan river), Montes municipality, Sucre state, as well as the analysis of faecal samples from inhabitants of towns bordering these tributaries were evaluated. We collected faecal and water samples from may 2006 through april 2007. The superficial water samples were processed after centrifugation by the direct examination and floculation, using lugol, modified Kinyoun and trichromic colorations. Fecal samples where analyzed by direct examination with physiological saline solution and the modified Ritchie concentration method and using the other colorations techniques above mentioned. The most frequently observed protozoans in superficial waters in the three tributaries were: Amoebas, Blastocystis sp, Endolimax sp., Chilomastix sp. and Giardia sp. Whereas in faecal samples, Blastocystis hominis, Endolimax nana and Entaomeba coli had the greatest frequencies in the three communities. The inhabitants of Orinoco La Peña turned out to be most susceptible to these parasitic infections (77.60%), followed by San Juan River (46.63%) and Quebrada Seca (39.49%). The presence of pathogenic and nonpathogenic protozoans in superficial waters demonstrates the faecal contamination of the tributaries, representing a constant focus of infection for their inhabitants, inferred by the observation of the same species in both types of samples. PMID:21365874

Mora, Leonor; Martínez, Indira; Figuera, Lourdes; Segura, Merlyn; Del Valle, Guilarte

2010-12-01

192

Spatiotemporal characteristics and mechanisms of intracellular Ca(2+) increases at fertilization in eggs of jellyfish (Phylum Cnidaria, Class Hydrozoa).  

PubMed

We have clarified, for the first time, the spatiotemporal patterns of intracellular Ca(2+) increases at fertilization and the Ca(2+)-mobilizing mechanisms in eggs of hydrozoan jellyfish, which belong to the evolutionarily old diploblastic phylum, Cnidaria. An initial Ca(2+) increase just after fertilization took the form of a Ca(2+) wave starting from one cortical region of the egg and propagating to its antipode in all of four hydrozoan species tested: Cytaeis uchidae, Cladonema pacificum, Clytia sp., and Gonionema vertens. The initiation site of the Ca(2+) wave was restricted to the animal pole, which is known to be the only area of sperm-egg fusion in hydrozoan eggs, and the wave propagating velocity was estimated to be 4.2-5.9 mum/s. After a Ca(2+) peak had been attained by the initial Ca(2+) wave, the elevated Ca(2+) gradually declined and returned nearly to the resting value at 7-10 min following fertilization. Injection of inositol 1,4,5-trisphosphate (IP(3)), an agonist of IP(3) receptors (IP(3)R), was highly effective in inducing a Ca(2+) increase in unfertilized eggs; IP(3) at a final intracellular concentration of 12-60 nM produced a fully propagating Ca(2+) wave equivalent to that observed at fertilization. In contrast, a higher concentration of cyclic ADP-ribose (cADPR), an agonist of ryanodine receptors (RyR), only generated a localized Ca(2+) increase that did not propagate in the egg. In addition, caffeine, another stimulator of RyR, was completely without effect. Sperm-induced Ca(2+) increases in Gonionema eggs were severely affected by preinjection of heparin, an inhibitor of Ca(2+) release from IP(3)R. These results strongly suggest that there is a well-developed IP(3)R-, but not RyR-mediated Ca(2+) release mechanism in hydrozoan eggs and that the former system primarily functions at fertilization. Our present data also demonstrate that the spatial characteristics and mechanisms of Ca(2+) increases at fertilization in hydrozoan eggs resemble those reported in higher triploblastic animals. PMID:15733659

Deguchi, Ryusaku; Kondoh, Eri; Itoh, Junko

2005-03-15

193

Morphology and histopathology of Calyptospora sp. (Apicomplexa: Calyptosporidae) in speckled peacock bass, Cichla temensis Humboldt, 1821 (Perciformes: Cichlidae), from the Marajó-Açu River, Marajó Island, Brazil.  

PubMed

Several species of coccidia are protozoan parasites that cause infection in a wide variety of animal groups. Calyptospora is an important genus of protozoan, which infests both freshwater and marine fish. The hepatopancreases of 150 speckled peacock bass captured on Marajó Island, Brazil were studied macro- and microscopically. Oocysts were found in 84 (56%) of the specimens in both the examination of the fresh material by compression and the analysis of histological sections stained with hematoxylin-eosin. Small, circular, homogeneous forms in negative contrast had a mean diameter of 21.2 ?m, frequently with pyriform sporocysts, with a mean length of 9.2 ?m and width of 3.1 ?m, and a thin-walled capsule, were observed in both the hepatic and the pancreatic parenchyma, but were completely devoid of any inflammatory reaction. Calyptospora infections are documented for the first time in the Marajó-Açu River. PMID:22200958

Santiago, Hérika; Corrêa, José Luís; Tortelly, Rogerio; Menezes, Rodrigo Caldas; Matos, Patrícia; Matos, Edilson

2012-06-01

194

Transcriptome Analysis of the Model Protozoan, Tetrahymena thermophila, Using Deep RNA Sequencing  

PubMed Central

Background The ciliated protozoan Tetrahymena thermophila is a well-studied single-celled eukaryote model organism for cellular and molecular biology. However, the lack of extensive T. thermophila cDNA libraries or a large expressed sequence tag (EST) database limited the quality of the original genome annotation. Methodology/Principal Findings This RNA-seq study describes the first deep sequencing analysis of the T. thermophila transcriptome during the three major stages of the life cycle: growth, starvation and conjugation. Uniquely mapped reads covered more than 96% of the 24,725 predicted gene models in the somatic genome. More than 1,000 new transcribed regions were identified. The great dynamic range of RNA-seq allowed detection of a nearly six order-of-magnitude range of measurable gene expression orchestrated by this cell. RNA-seq also allowed the first prediction of transcript untranslated regions (UTRs) and an updated (larger) size estimate of the T. thermophila transcriptome: 57 Mb, or about 55% of the somatic genome. Our study identified nearly 1,500 alternative splicing (AS) events distributed over 5.2% of T. thermophila genes. This percentage represents a two order-of-magnitude increase over previous EST-based estimates in Tetrahymena. Evidence of stage-specific regulation of alternative splicing was also obtained. Finally, our study allowed us to completely confirm about 26.8% of the genes originally predicted by the gene finder, to correct coding sequence boundaries and intron-exon junctions for about a third, and to reassign microarray probes and correct earlier microarray data. Conclusions/Significance RNA-seq data significantly improve the genome annotation and provide a fully comprehensive view of the global transcriptome of T. thermophila. To our knowledge, 5.2% of T. thermophila genes with AS is the highest percentage of genes showing AS reported in a unicellular eukaryote. Tetrahymena thus becomes an excellent unicellular model eukaryote in which to investigate mechanisms of alternative splicing. PMID:22347391

Xiong, Jie; Lu, Xingyi; Zhou, Zhemin; Chang, Yue; Yuan, Dongxia; Tian, Miao; Zhou, Zhigang; Wang, Lei; Fu, Chengjie; Orias, Eduardo; Miao, Wei

2012-01-01

195

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

PubMed

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

Hawash, Yousry

2014-06-01

196

The natural resistance-associated macrophage protein from the protozoan parasite Perkinsus marinus mediates iron uptake.  

PubMed

Microbial pathogens succeed in acquiring essential metals such as iron and manganese despite their limited availability because of the host's immune response. The eukaryotic natural resistance-associated macrophage proteins mediate uptake of divalent metals and, during infection, may compete directly for metal acquisition with the pathogens' transporters. In this study, we characterize the Nramp gene family of Perkinsus marinus, an intracellular parasite of the eastern oyster, and through yeast complementation, we demonstrate for the first time for a protozoan parasite that Nramp imports environmental Fe. Three PmNramp isogenes differ in their exon-intron structures and encode transcripts that display a trans splicing leader at the 5' end. The protein sequences share conserved properties predicted for the Nramp/Solute carrier 11 (Slc11) family, such as 12-transmembrane segment (TMS) topology (N- and C-termini cytoplasmic) and preferential conservation of four TMS predicted to form a pseudosymmetric proton/metal symport pathway. Yeast fet3fet4 mutant complementation assays showed iron transport activity for PmNramp1 and a fusion chimera of the PmNramp3 hydrophobic core and PmNramp1 N- and C-termini. PmNramp1 site-directed mutagenesis demonstrated that Slc11 invariant and predicted pseudosymmetric motifs (TMS1 Asp-Pro-Gly and TMS6 Met-Pro-His) are key for transport function. PmNramp1 TMS1 mutants D76E, G78A, and D76E/G78A prevented membrane protein expression, while TMS6 M250A, H252Y, and M250A/H252Y specifically abrogated Fe uptake; the TMS6 H252Y mutation also correlates with divergence from Nramp specificity for divalent metals. PMID:21661746

Lin, Zhuoer; Fernández-Robledo, José-Antonio; Cellier, Mathieu F M; Vasta, Gerardo R

2011-07-26

197

Transcriptional regulation of two stage-specifically expressed genes in the protozoan parasite Toxoplasma gondii  

PubMed Central

The protozoan parasite Toxoplasma gondii differentially expresses two distinct enolase isoenzymes known as ENO1 and ENO2, respectively. To understand differential gene expression during tachyzoite to bradyzoite conversion, we have characterized the two T.gondii enolase promoters. No homology could be found between these sequences and no TATA or CCAAT boxes were evident. The differential activation of the ENO1 and ENO2 promoters during tachyzoite to bradyzoite differentiation was investigated by deletion analysis of 5?-flanking regions fused to the chloramphenicol acetyltransferase reporter followed by transient transfection. Our data indicate that in proliferating tachyzoites, the repression of ENO1 involves a negative distal regulatory region (nucleotides ?1245 to ?625) in the promoter whereas a proximal regulatory region in the ENO2 promoter directs expression at a low level. In contrast, the promoter activity of ENO1 is highly induced following the conversion of tachyzoites into resting bradyzoites. The ENO2 promoter analysis in bradyzoites showed that there are two upstream repression sites (nucleotides ?1929 to ?1067 and ?456 to ?222). Furthermore, electrophoresis mobility shift assays demonstrated the presence of DNA-binding proteins in tachyzoite and bradyzoite nuclear lysates that bound to stress response elements (STRE), heat shock-like elements (HSE) and other cis-regulatory elements in the upstream regulatory regions of ENO1 and ENO2. Mutation of the consensus AGGGG sequence, completely abolished protein binding to an oligonucleotide containing this element. This study defines the first characterization of cis-regulatory elements and putative transcription factors involved in gene regulation of the important pathogen T.gondii. PMID:15784612

Kibe, Michael K.; Coppin, Alexandra; Dendouga, Najoua; Oria, Gabrielle; Meurice, Edwige; Mortuaire, Marlène; Madec, Edwige; Tomavo, Stanislas

2005-01-01

198

Functional Characterization of Peroxiredoxins from the Human Protozoan Parasite Giardia intestinalis  

PubMed Central

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

Testa, Fabrizio; Pucillo, Leopoldo Paolo; Teixeira, Miguel; Sarti, Paolo; Saraiva, Ligia M.; Giuffre, Alessandro

2014-01-01

199

Protozoans as indicators of sequential batch processes for phenol treatment; an autoecological approach.  

PubMed

The objective of this study was the investigation of the potential use of protistan species as quality indicators of the activated sludge performance in sequential batch processes receiving toxic compounds. Two laboratory scale sequential batch reactors (SBR) were used, a conventional one and a system with plastic biofilm carriers (SBBR), treating wastewater containing phenol at concentrations ranging from 1 up to 40 mg/L. Physicochemical analyses of the samples included the determination of MLSS, effluent suspended solids, BOD5, nitrogen-ammonia, nitrogen-nitrate and phenol. The activated sludge protistan community was identified and enumerated in each reactor. Statistical analyses included Canonical Correspondence Analysis and Indicator Species Analysis of the collected experimental data. Canonical Correspondence Analysis showed inversely proportional relationships between the protozoa and the physicochemical parameters of the effluent as well as protozoan species competition. Indicator species analysis revealed the presence and the prevalence of different species under various phenol influent concentrations. No indicator species were observed for the period of operation under 5 mg/L influent phenol in both reactors, while no indicator species were observed for 20 mg/L influent phenol in the SBR reactor. Carchesium and Epistylis sp. showed the higher values for 1 mg/L phenol in the SBR, while Holophrya sp. showed lower indicator values for the same period in the SBBR. Although several species showed a good correlation to the treatment efficiency of the reactors, Blepharisma sp., could be used as the primary indicator species in both reactors for the operation period under 40 mg/L phenol, as deduced by statistical analysis. PMID:24070776

Papadimitriou, C A; Petridis, D; Zouboulis, A I; Samaras, P; Yiangou, M; Sakellaropoulos, G P

2013-12-01

200

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

PubMed Central

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

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

2012-01-01

201

Protozoan Predation Is Differentially Affected by Motility of Enteric Pathogens in Water vs. Sediments.  

PubMed

Survival of enteric bacteria in aquatic habitats varies depending upon species, strain, and environmental pressures, but the mechanisms governing their fate are poorly understood. Although predation by protozoa is a known, top-down control mechanism on bacterial populations, its influence on the survival of fecal-derived pathogens has not been systematically studied. We hypothesized that motility, a variable trait among pathogens, can influence predation rates and bacterial survival. We compared the survival of two motile pathogens of fecal origin by culturing Escherichia coli O157 and Salmonella enterica Typhimurium. Each species had a motile and non-motile counterpart and was cultured in outdoor microcosms with protozoan predators (Tetrahymena pyriformis) present or absent. Motility had a significant, positive effect on S. enterica levels in water and sediment in the presence or absence of predators. In contrast, motility had a significant negative effect on E. coli O157 levels in sediment, but did not affect water column levels. The presence/absence of protozoa consistently accounted for a greater proportion of the variability in bacterial levels (>95 %) than in bacterial motility (<4 %) in the water column. In sediments, however, motility was more important than predation for both bacteria. Calculations of total CFU/microcosm showed decreasing bacterial concentrations over time under all conditions except for S. enterica in the absence of predation, which increased ?0.5-1.0 log over 5 days. These findings underscore the complexity of predicting the survival of enteric microorganisms in aquatic habitats, which has implications for the accuracy of risk assessment and modeling of water quality. PMID:24952019

Wanjugi, Pauline; Harwood, Valerie J

2014-11-01

202

Interaction network of the 14-3-3 protein in the ancient protozoan parasite Giardia duodenalis.  

PubMed

14-3-3s are phosphoserine/phosphotreonine binding proteins that play pivotal roles as regulators of multiple cellular processes in eukaryotes. The flagellated protozoan parasite Giardia duodenalis, the causing agent of giardiasis, is a valuable simplified eukaryotic model. A single 14-3-3 isoform (g14-3-3) is expressed in Giardia, and it is directly involved in the differentiation of the parasite into cyst. To define the overall functions of g14-3-3, the protein interactome has been investigated. A transgenic G. duodenalis strain was engineered to express a FLAG-tagged g14-3-3 under its own promoter. Affinity chromatography coupled with tandem mass spectrometry analysis have been used to purify and identify FLAG-g14-3-3-associated proteins from trophozoites and encysting parasites. A total of 314 putative g14-3-3 interaction partners were identified, including proteins involved in several pathways. Some interactions seemed to be peculiar of one specific stage, while others were shared among the different stages. Furthermore, the interaction of g14-3-3 with the giardial homologue of the CDC7 protein kinase (gCDC7) was characterized, leading to the identification of a multiprotein complex containing not only g14-3-3 and gCDC7 but also a newly identified and highly divergent homologue of DBF4, the putative regulatory subunit of gCDC7. The relevance of g14-3-3 interactions in G. duodenalis biology was discussed. PMID:22452640

Lalle, Marco; Camerini, Serena; Cecchetti, Serena; Sayadi, Ahmed; Crescenzi, Marco; Pozio, Edoardo

2012-05-01

203

Polymorphic family of injected pseudokinases is paramount in Toxoplasma virulence  

E-print Network

Toxoplasma gondii, an obligate intracellular parasite of the phylum Apicomplexa, has the unusual ability to infect virtually any warm-blooded animal. It is an extraordinarily successful parasite, infecting an estimated 30% ...

Reese, Michael L.

204

Revision of the genus Xiphocephalus and description of Xiphocephalus ellisi n. sp. (Apicomplexa: Eugregarinida: Stylocephalidae) from Eleodes opacus (Coleoptera: Tenebrionidae) in the western Nebraska Sandhills.  

PubMed

Xiphocephalus is revised, clarifying diagnosis of the epimerite complex, gametocyst, and oocyst. Xiphocephalus ellisi n. sp. (Apicomplexa: Eugregarinida) is described from Eleodes opacus (Coleoptera: Tenebrionidae) collected from Keith County in the Sandhills of western Nebraska. Measurements are means in micrometers. Developing trophozoites solitary; epimerite a complex of terminal epimerite and intercalating diamerite: epimerite elongate, ensiform, with transverse basal tumidus, length 2-3 times width of basal tumidus; width approximately half that of basal tumidus; tumidus toroidal, concavoconcave in anterioposterior axis: diamerite roughly cylindrical, no longitudinal fold apparent, length approximately twice width. Association late, frontal, isogamontic. Protomerite depressed ovoid, length 84.1, width 114.9, anterior distance to widest point 50.8. Protomerite-deutomerite septum clearly marked and constricted, width 99.3. Deutomerite narrowly obovoid, length 1,094.0, maximum width 197.0, anterior distance to widest point 137.8, equatorial width 163.3. Total length 1,204.4. Nucleus ellipsoid, length 64.9, width 42.2; typically with 2-3 polysomal endosomes. Gametocysts roughly spherical, length 376.1, width 348.2, wall paperlike, papillated, dehiscing by simple rupture, releasing oocysts in coiled chains, epispore packet absent, gametocyst residuum present. Oocysts brown to black, broadly deltoid, gibbous in lateral aspect, slightly keeled in dorsal aspect, length 9.7, height 8.5; with terminal protuberances and a single, central, spherical residuum. PMID:10207369

Clopton, R E

1999-02-01

205

A new species of Caryospora Léger, 1904 (Apicomplexa: Eimeriidae) from the endangered Round Island boa Casarea dussumieri (Schlegel) (Serpentes: Bolyeridae) of Round Island, Mauritius: an endangered parasite?  

PubMed

A new species of Caryospora Léger, 1904 (Apicomplexa: Eimeriidae), C. durelli n. sp., is described from the endangered Round Island boa Casarea dussumieri (Schlegel) (Serpentes: Bolyeridae) from Round Island, Mauritius. Six of 11 hosts were infected. Oöcysts are spherical to subspherical, 19.2 × 18.2 (17.5-21 × 16-21) ?m, n = 20, and have a shape index (mean length/mean width) of 1.05 (1.02-1.09). The bi-layered wall is composed of an outer layer of c.0.6 ?m thick and an inner layer of c.0.4 ?m thick. A micropyle, oöcyst residuum and polar granule are absent. Sporocysts are ellipsoidal, 14.7 × 11.0 (13-16 × 9.5-11.5) ?m, n = 20, and have a shape index of 1.33. Both Stieda and substieda bodies are present. The sporocyst residuum measures c.12 × 4.5 ?m, is surrounded by sporozoites and composed of numerous granules. Refractile bodies are present but not clearly visible. This is the first coccidian parasite reported from the family Bolyeridae and the first species of Caryospora durrelli [corrected] reported from the Mascarenes. Conservation issues concerning parasites of endangered host species are discussed. PMID:21279561

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

2011-02-01

206

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

PubMed

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

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

207

Development of Single-Nucleotide Polymorphism- Based Phylum-Specific PCR Amplification Technique: Application to the Community Analysis Using Ciliates as a Reference Organism  

PubMed Central

Despite recent advance in mass sequencing technologies such as pyrosequencing, assessment of culture-independent microbial eukaryote community structures using universal primers remains very difficult due to the tremendous richness and complexity of organisms in these communities. Use of a specific PCR marker targeting a particular group would provide enhanced sensitivity and more in-depth evaluation of microbial eukaryote communities compared to what can be achieved with universal primers. We discovered that many phylum- or group-specific single-nucleotide polymorphisms (SNPs) exist in small subunit ribosomal RNA (SSU rRNA) genes from diverse eukaryote groups. By applying this discovery to a known simple allele-discriminating (SAP) PCR method, we developed a technique that enables the identification of organisms belonging to a specific higher taxonomic group (or phylum) among diverse types of eukaryotes. We performed an assay using two complementary methods, pyrosequencing and clone library screening. In doing this, specificities for the group (ciliates) targeted in this study in bulked environmental samples were 94.6% for the clone library and 99.2% for pyrosequencing, respectively. In particular, our novel technique showed high selectivity for rare species, a feature that may be more important than the ability to identify quantitatively predominant species in community structure analyses. Additionally, our data revealed that a target-specific library (or ciliate-specific one for the present study) can better explain the ecological features of a sampling locality than a universal library. PMID:22965748

Jung, Jae-Ho; Kim, Sanghee; Ryu, Seongho; Kim, Min-Seok; Baek, Ye-Seul; Kim, Se-Joo; Choi, Joong- Ki; Park, Joong-Ki; Min, Gi-Sik

2012-01-01

208

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

PubMed

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 triploblastic Bilateria. Cnidarians are generally regarded as diploblastic animals, possessing endoderm and ectoderm, but lacking mesoderm. To investigate the origin of triploblasty, we studied the developmental expression of seven genes from Nematostella whose bilaterian homologs are implicated in mesodermal specification and the differentiation of mesodermal cell types (twist, snailA, snailB, forkhead, mef2, a GATA transcription factor and a LIM transcription factor). Except for mef2, the expression of these genes is largely restricted to the endodermal layer, the gastrodermis. mef2 is restricted to the ectoderm. The temporal and spatial expression of these 'mesoderm' genes suggests that they may play a role in germ layer specification. Furthermore, the predominantly endodermal expression of these genes reinforces the hypothesis that the mesoderm and endoderm of triploblastic animals could be derived from the endoderm of a diploblastic ancestor. Alternatively, we consider the possibility that the diploblastic condition of cnidarians is a secondary simplification, derived from an ancestral condition of triploblasty. PMID:15128674

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

2004-05-01

209

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

PubMed Central

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

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

2014-01-01

210

Analysis of the bovine rumen microbiome reveals a diversity of Sus-like polysaccharide utilization loci from the bacterial phylum Bacteroidetes.  

PubMed

Several unique Sus-like polysaccharide utilization loci (PULs) were identified from bacteria resident in bovine rumen microbiomes through functional screening of a fosmid library. The loci were phylogenetically assigned to the genus Prevotella within the phylum Bacteroidetes. These findings were augmented by a bioinformatic re-evaluation of ruminal Prevotella genomes, revealing additional loci not previously reported in the literature. Analysis of Bacteroidales-affiliated genomes reconstructed from a bovine rumen metagenome in a previous study further expanded the diversity of Sus-like PULs resident in this microbiome. Our findings suggest that Sus-like systems represent an important mechanism for degradation of a range of plant-derived glycans in ruminants. PMID:24448980

Rosewarne, Carly P; Pope, Phillip B; Cheung, Jane L; Morrison, Mark

2014-03-01

211

Species of coccidia (Apicomplexa: Eimeriidae) in shrews from Alaska, U.S.A., and northeastern Siberia, Russia, with description of two new species.  

PubMed

Fecal samples (n = 636) from 10 species of shrews collected in Alaska (n = 540) and northeastern Siberia (n = 96) were examined for the presence of coccidia (Apicomplexa: Eimeriidae). Five distinct oocyst morphotypes were observed. Three types were consistent with oocysts of previously recognized coccidia species from other shrew hosts. These were Eimeria inyoni, E. vagrantis, and Isospora brevicauda, originally described from the inyo shrew (Sorex tenellus), dusky shrew (S. monticolus), and northern short-tailed shrew (Blarina brevicauda), respectively. We found 5 new host records for E. inyoni, 3 for E. vagrantis, and 3 for I. brevicauda. The 2 additional oocyst morphotypes, both from the tundra shrew (Sorex tundrensis), are putative new species. Sporulated oocysts of Eimeria beringiacea n. sp. are subspheroidal, 17.7 x 15.6 microm (14-24 x 13-20 microm) with a length (L)/width (W) ratio of 1.1 (1.0-1.4); these lack a micropyle (M), an oocyst residuum (OR), and a polar granule (PG). Sporocysts are ellipsoidal, 10.3 x 6.1 microm (7-14 x 4-8 microm), with a L/W ratio of 1.7 (1.3-2.3) and have a Stieda body (SB), Substieda body (SSB), and sporocyst residuum (SR). Oocysts of Eimeria tundraensis n. sp. are spheroidal to subspheroidal, 24.8 x 23.5 microm (23-26 x 22-25 microm), with a L/W ratio of 1.1 (1.0-1.2); these lack a M and OR, but a single PG is present. Sporocysts are elongate ellipsoidal, 15.4 x 8.3 microm (13-17 x 7-9 microm), with a L/W ratio of 1.9 (1.4-2.1) and have a SB, SSB, and SR. PMID:18576829

Lynch, A J; Duszynski, D W

2008-08-01

212

Molecular assessment of hepatozoon (Apicomplexa: adeleorina) infections in wild canids and rodents from north Africa, with implications for transmission dynamics across taxonomic groups.  

PubMed

Parasites play a major role in ecosystems, and understanding of host-parasite interactions is important for predicting parasite transmission dynamics and epidemiology. However, there is still a lack of knowledge about the distribution, diversity, and impact of parasites in wildlife, especially from remote areas. Hepatozoon is a genus of apicomplexan parasites that is transmitted by ingestion of infected arthropod vectors. However, alternative modes of transmission have been identified such as trophic transmission. Using the 18S rRNA gene as a marker, we provide an assessment of Hepatozoon prevalence in six wild canid and two rodent species collected between 2003 and 2012 from remote areas in North Africa. By combining this with other predator-prey systems in a phylogenetic framework, we investigate Hepatozoon transmission dynamics in distinct host taxa. Prevalence was high overall among host species (African jerboa Jaculus jaculus [17/47, 36%], greater Egyptian jerboa Jaculus orientalis [5/7, 71%], side-striped jackal Canis adustus [1/2, 50%], golden jackal Canis aureus [6/32, 18%], pale fox Vulpes pallida [14/28, 50%], Rüppell's fox Vulpes rueppellii [6/11, 55%], red fox Vulpes vulpes [8/16, 50%], and fennec fox Vulpes zerda [7/11, 42%]). Phylogenetic analysis showed further evidence of occasional transmission of Hepatozoon lineages from prey to canid predators, which seems to occur less frequently than in other predator-prey systems such as between snakes and lizards. Due to the complex nature of the Hepatozoon lifecycle (heteroxenous and vector-borne), future studies on these wild host species need to clarify the dynamics of alternative modes of Hepatozoon transmission and identify reservoir and definitive hosts in natural populations. We also detected putative Babesia spp. (Apicomplexa: Piroplasmida) infections in two canid species from this region, V. pallida (1/28) and V. zerda (1/11). PMID:25050803

Maia, João P; Alvares, Francisco; Boraty?ski, Zbyszek; Brito, José C; Leite, João V; Harris, D James

2014-10-01

213

Protozoan and myxozoan infections in wild gilthead seabream (Sparus aurata L.) from North Lake of Tunis, Tunisia.  

PubMed

A total of 150 gilthead seabream Sparus aurata L., from North Lake of Tunis, Tunisia, were studied for protozoan and myxozoan parasites. The parasitological survey revealed the presence of ectoparasites (Amyloodinium ocellatum Brown, 1931, Trichodina lepsii Lom, 1962 on the gills) and endoparasites (Ceratomyxa sparusaurati Sitjà-Bobadilla, Palenzuela et Alvarez-Pellitero, 1995 infecting the gallbladder, and Eimeria sparis Sitjà-Bobadilla, Palenzuela et Alvarez-Pellitero, 1996 parasitizing the intestine). This is the first record of Amyloodinium ocellatum, Trichodina lepsii, Ceratomyxa sparusaurati, and Eimeria sparis in S. aurata from Tunisian waters. Data on prevalence and intensity of infection are provided. A comparison of the present species with previously described species in cultured gilthead seabream from other Mediterranean countries is also presented. In this study Trichodina lepsii is identified for the first time in Sparus aurata. A taxonomic description of this species based on silver nitrate method is provided. PMID:22807047

Bahri, Sihem

2012-06-01

214

Herbicides to curb human parasitic infections: in vitro and in vivo effects of trifluralin on the trypanosomatid protozoans.  

PubMed Central

Leishmaniasis is a major tropical disease for which current chemotherapies, pentavalent antimonials, are inadequate and cause severe side effects. It has been reported that trifluralin, a microtubule-disrupting herbicide, is inhibitory to Leishmania amazonensis. In this study, the in vitro effect of trifluralin on different species of trypanosomatid protozoans was determined. In addition to L. amazonensis, trifluralin is effective against Leishmania major and Leishmania tropica, which cause cutaneous infections, Leishmania donovani, which causes visceral disease, Leishmania panamensis, which may cause mucocutaneous infection, and Trypanosoma brucei, an important human and veterinary pathogen. Moreover, most encouragingly, trifluralin is effective in vivo as a topical ointment against L. major and Leishmania mexicana murine cutaneous leishmaniasis. Thus, trifluralin is a promising lead drug for several related, prevalent tropical diseases: leishmaniasis, trypanosomiasis of animals, and, possibly, African trypanosomiasis in humans. Images Fig. 4 PMID:8516314

Chan, M M; Grogl, M; Chen, C C; Bienen, E J; Fong, D

1993-01-01

215

A Non-Long Terminal Repeat Retrotransposon Family Is Restricted to the Germ Line Micronucleus of the Ciliated Protozoan Tetrahymena thermophila  

Microsoft Academic Search

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 iden- tified several members of a family of non-long terminal repeat (LTR) retrotransposons (retroposons) in T. thermophila, the first characterized in the

Jeffrey S. Fillingham; Trine A. Thing; Nama Vythilingum; Alex Keuroghlian; Deanna Bruno; G. Brian Golding; Ronald E. Pearlman

2004-01-01

216

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

#12;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- specific marker Michael F. Cohen1,2* and Mark Mazzola1 1 Tree Fruit Research Laboratory USDA-Agricultural Research Service 1104 N

Cohen, Michael F.

217

The protozoan inositol phosphorylceramide synthase: a novel drug target that defines a new class of sphingolipid synthase.  

PubMed

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 utilize phytoceramide in the synthesis of inositol phosphorylceramide (IPC) catalyzed by IPC synthase. Because of 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 data bases of these species. By utilizing 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 that defines a new class of protozoan sphingolipid synthase. The identification and characterization 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

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

2006-09-22

218

Application of magnetically induced hyperthermia in the model protozoan Crithidia fasciculata as a potential therapy against parasitic infections  

PubMed Central

Background Magnetic hyperthermia is currently a clinical therapy approved in the European Union for treatment of tumor cells, and uses magnetic nanoparticles (MNPs) under time-varying magnetic fields (TVMFs). The same basic principle seems promising against trypanosomatids causing Chagas disease and sleeping sickness, given that the therapeutic drugs available have severe side effects and that there are drug-resistant strains. However, no applications of this strategy against protozoan-induced diseases have been reported so far. In the present study, Crithidia fasciculata, a widely used model for therapeutic strategies against pathogenic trypanosomatids, was targeted with Fe3O4 MNPs in order to provoke cell death remotely using TVMFs. Methods Iron oxide MNPs with average diameters of approximately 30 nm were synthesized by precipitation of FeSO4 in basic medium. The MNPs were added to C. fasciculata choanomastigotes in the exponential phase and incubated overnight, removing excess MNPs using a DEAE-cellulose resin column. The amount of MNPs uploaded per cell was determined by magnetic measurement. The cells bearing MNPs were submitted to TVMFs using a homemade AC field applicator (f = 249 kHz, H = 13 kA/m), and the temperature variation during the experiments was measured. Scanning electron microscopy was used to assess morphological changes after the TVMF experiments. Cell viability was analyzed using an MTT colorimetric assay and flow cytometry. Results MNPs were incorporated into the cells, with no noticeable cytotoxicity. When a TVMF was applied to cells bearing MNPs, massive cell death was induced via a nonapoptotic mechanism. No effects were observed by applying TVMF to control cells not loaded with MNPs. No macroscopic rise in temperature was observed in the extracellular medium during the experiments. Conclusion As a proof of principle, these data indicate that intracellular hyperthermia is a suitable technology to induce death of protozoan parasites bearing MNPs. These findings expand the possibilities for new therapeutic strategies combating parasitic infection. PMID:23071396

Grazu, V; Silber, AM; Moros, M; Asin, L; Torres, TE; Marquina, C; Ibarra, MR; Goya, GF

2012-01-01

219

Litorilinea aerophila gen. nov., sp. nov., an aerobic member of the class Caldilineae, phylum Chloroflexi, isolated from an intertidal hot spring.  

PubMed

A thermophilic, aerobic, Gram-stain-negative, filamentous bacterium, strain PRI-4131(T), was isolated from an intertidal hot spring in Isafjardardjup, NW Iceland. The strain grew chemo-organotrophically on various carbohydrates. The temperature range for growth was 40-65 °C (optimum 55 °C), the pH range was pH 6.5-9.0 (optimum pH 7.0) and the NaCl range was 0-3?% (w/v) (optimum 0.5?%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PRI-4131(T) represented a distinct lineage within the class Caldilineae of the phylum http://dx.doi.org/10.1601/nm.550Chloroflexi. The highest levels of sequence similarity, about 91?%, were with Caldilinea aerophila STL-6-O1(T) and Caldilinea tarbellica D1-25-10-4(T). Fermentative growth was not observed for strain PRI-4131(T), which, in addition to other characteristics, distinguished it from the two Caldilinea species. Owing to both phylogenetic and phenotypic differences from the described members of the class Caldilineae, we propose to accommodate strain PRI-4131(T) in a novel species in a new genus, Litorilinea aerophila gen. nov., sp. nov. The type strain of Litorilinea aerophila is PRI-4131(T) (?=?DSM 25763(T) ?=?ATCC BAA-2444(T)). PMID:22771681

Kale, Varsha; Björnsdóttir, Snædís H; Friðjónsson, Ólafur H; Pétursdóttir, Sólveig K; Ómarsdóttir, Sesselja; Hreggviðsson, Guðmundur Óli

2013-03-01

220

Organization and Nucleotide Sequence of the Cluster of Five Histone Genes in the Polichaete Worm Chaetopterus variopedatus: First Record of a H1 Histone Gene in the Phylum Annelida  

Microsoft Academic Search

.   Histone genes were identified and their nucleotide sequences were determined in the polychaete marine worm Chaetopterus variopedatus. The genes are organized in about 390 clusters of 7.3 kbp. Each cluster contains one copy of the five histone genes. The H1\\u000a histone gene present in the clusters is the first ever isolated in the phylum Annelida. The cluster has the

Rosanna del Gaudio; Nicoletta Potenza; Patrizia Stefanoni; Maria L. Chiusano; Giuseppe Geraci

1998-01-01

221

The search for the missing link: a relic plastid in Perkinsus?  

PubMed

Perkinsus marinus (Phylum Perkinsozoa) is a protozoan parasite that has devastated natural and farmed oyster populations in the USA, significantly affecting the shellfish industry and the estuarine environment. The other two genera in the phylum, Parvilucifera and Rastrimonas, are parasites of microeukaryotes. The Perkinsozoa occupies a key position at the base of the dinoflagellate branch, close to its divergence from the Apicomplexa, a clade that includes parasitic protista, many harbouring a relic plastid. Thus, as a taxon that has also evolved toward parasitism, the Perkinsozoa has attracted the attention of biologists interested in the evolution of this organelle, both in its ultrastructure and the conservation, loss or transfer of its genes. A review of the recent literature reveals mounting evidence in support of the presence of a relic plastid in P. marinus, including the presence of multimembrane structures, characteristic metabolic pathways and proteins with a bipartite N-terminal extension. Further, these findings raise intriguing questions regarding the potential functions and unique adaptation of the putative plastid and/or plastid genes in the Perkinsozoa. In this review we analyse the above-mentioned evidence and evaluate the potential future directions and expected benefits of addressing such questions. Given the rapidly expanding molecular/genetic resources and methodological toolbox for Perkinsus spp., these organisms should complement the currently established models for investigating plastid evolution within the Chromalveolata. PMID:21889509

Fernández Robledo, José A; Caler, Elisabet; Matsuzaki, Motomichi; Keeling, Patrick J; Shanmugam, Dhanasekaran; Roos, David S; Vasta, Gerardo R

2011-10-01

222

Culture-dependent and independent analyses of the microbial communities inhabiting the giant duckweed (Spirodela polyrrhiza) rhizoplane and isolation of a variety of rarely cultivated organisms within the phylum Verrucomicrobia.  

PubMed

The microbial communities of the rhizoplane, the surface part of roots, in aquatic plants are not understood at all. In this study, we analyzed microbial communities in the rhizoplane of a floating aquatic plant, giant duckweed (Spirodela polyrrhiza), based on cultivation-dependent and independent analyses. The cultivation-based analysis using agar and gellan gum plates revealed that the rhizoplane isolates were affiliated with four bacterial lineages; the Alphaproteobacteria, Betaproteobacteria, Bacteroidetes and Verrucomicrobia. Interestingly, microbes belonging to the phylum Verrucomicrobia accounted for 24% of all the isolates, suggesting that the rhizoplane of S. polyrrhiza forms a specific habitat for the organisms within this phylum. Culture-independent 16S rRNA gene cloning showed that the clonal sequences were affiliated with eight bacterial classes and phyla: the classes Alphaproteobacteria (14% total clones), Betaproteobacteria (45%), Gammaproteobacteria (2%) and Deltaproteobacteria (2%), and the phyla Bacteroidetes (11%), Verrucomicrobia (2%), Planctomycetes (2%) and Cyanobacteria (22%). Comparative analysis of the microbial communities in the rhizoplane between culture-dependent and independent methods revealed that 33% of the taxonomic groups of bacterial species detected in the molecular analysis were cultivable. Our findings suggest that the microbes in the rhizoplane of giant duckweed are comprised of a diverse array of readily cultured organisms including a variety of strains within the Verrucomicrobia, a well-known phylum that contains a number of yet-to-be cultivated organisms. PMID:21576886

Matsuzawa, Hiroaki; Tanaka, Yasuhiro; Tamaki, Hideyuki; Kamagata, Yoichi; Mori, Kazuhiro

2010-01-01

223

The water-born protein pheromones of the polar protozoan ciliate, Euplotes nobilii: Coding genes and molecular structures  

NASA Astrophysics Data System (ADS)

The protozoan ciliate Euplotes nobilii found in Antarctic and Arctic coastal waters relies on secretion of water-soluble cell type-specific signal proteins (pheromones) to regulate its vegetative growth and sexual mating. For three of these psychrophilic pheromones we previously determined the three-dimensional structures by nuclear magnetic resonance (NMR) spectroscopy with protein solutions purified from the natural sources, which led to evidence that their adaptation to cold is primarily achieved by increased flexibility through an extension of regions free of regular secondary structures, and by increased exposure of negative charges on the protein surface. Then we cloned the coding genes of these E. nobilii pheromones from the transcriptionally active cell somatic nucleus (macronucleus) and characterized the full-length sequences. These sequences all contain an open reading frame of 252-285 nucleotides, which is specific for a cytoplasmic pheromone precursor that requires two proteolytic cleavages to remove a signal peptide and a pro segment before release of the mature protein into the extracellular environment. The 5? and 3? non-coding regions are two- to three-fold longer than the coding region and appear to be tightly conserved, probably in relation to the inclusion of intron sequences destined to be alternatively removed to play key regulatory roles in the mechanism of the pheromone gene expression.

Vallesi, Adriana; Alimenti, Claudio; Di Giuseppe, Graziano; Dini, Fernando; Pedrini, Bill; Wüthrich, Kurt; Luporini, Pierangelo

2010-08-01

224

Styrax japonica supplementation diet enhances the innate immune response in Epinephelus bruneus against bacterial and protozoan infections.  

PubMed

Kelp grouper, Epinephelus bruneus, fed for 30 days with 0% (control), 0.1%, 1.0%, and 2.0% of Styrax japonica supplementation diets, led to reductions in mortality after being challenged with a bacterium (Vibrio harveyi) and a ciliate protozoan (Uronema marinum). The enriched diets significantly increased the survival rate as compared to the controls. The phagocytic and respiratory activities were significantly increased in kelp groupers given 1.0% and 2.0% enriched diets. The complement activity, lysozyme activity, serum bactericidal activity, and total protein level significantly increased with any enriched diet against the pathogens; however antiprotease activity and myeloperoxidase levels significantly increased only with 1.0% and 2.0% enriched diets while the ?2-macroglobulin level was significantly enhanced with 1.0% enriched diet. The study suggests that incorporation of S. japonica at 1.0% and 2.0% level in the diet significantly enhances the immune responses in the kelp grouper E. bruneus against V. harveyi and U. marinum. PMID:21824474

Harikrishnan, Ramasamy; Kim, Ju-Sang; Kim, Man-Chul; Balasundaram, Chellam; Heo, Moon-Soo

2011-11-01

225

Anion inhibition studies of the ?-carbonic anhydrase from the protozoan pathogen Trypanosoma cruzi, the causative agent of Chagas disease.  

PubMed

The protozoan pathogen Trypanosoma cruzi, the causative agent of Chagas disease, encodes an ?-class carbonic anhydrase (CA, EC 4.2.1.1), TcCA, which was recently shown to be crucial for its life cycle. Thiols, a class of strong TcCA inhibitors, were also shown to block the growth of the pathogen in vitro. Here we report the inhibition of TcCA by inorganic and complex anions and other molecules interacting with zinc proteins, such as sulfamide, sulfamic acid, phenylboronic/arsonic acids. TcCA was inhibited in the low micromolar range by iodide, cyanate, thiocyanate, hydrogensulfide and trithiocarbonate (KIs in the range of 44-93 ?M), but the best inhibitor was diethyldithiocarbamate (KI=5 ?M). Sulfamide showed an inhibition constant of 120 ?M, but sulfamic acid was much less effective (KI of 10.6 mM). The discovery of diethyldithiocarbamate as a low micromolar TcCA inhibitor may be useful to detect leads for developing anti-Trypanosoma agents with a diverse mechanism of action compared to clinically used drugs (benznidazole, nifurtimox) for which significant resistance emerged. PMID:23790722

Pan, Peiwen; Vermelho, Alane Beatriz; Scozzafava, Andrea; Parkkila, Seppo; Capasso, Clemente; Supuran, Claudiu T

2013-08-01

226

The effect of tunicamycin on the glucose uptake, growth, and cellular adhesion in the protozoan parasite Crithidia fasciculata.  

PubMed

Crithidia fasciculata represents a very interesting model organism to study biochemical, cellular, and genetic processes unique to members of the family of the Trypanosomatidae. Thus, C. fasciculata parasitizes several species of insects and has been widely used to test new therapeutic strategies against parasitic infections. By using tunicamycin, a potent inhibitor of glycosylation in asparaginyl residues of glycoproteins (N-glycosylation), we demonstrate that N-glycosylation in C. fasciculata cells is involved in modulating glucose uptake, dramatically impacting growth, and cell adhesion. C. fasciculata treated with tunicamycin was severely affected in their ability to replicate and to adhere to polystyrene substrates and losing their ability to aggregate into small and large groups. Moreover, under tunicamycin treatment, the parasites were considerably shorter and rounder and displayed alterations in cytoplasmic vesicles formation. Furthermore, glucose uptake was significantly impaired in a tunicamycin dose-dependent manner; however, no cytotoxic effect was observed. Interestingly, this effect was reversible. Thus, when tunicamycin was removed from the culture media, the parasites recovered its growth rate, cell adhesion properties, and glucose uptake. Collectively, these results suggest that changes in the tunicamycin-dependent glycosylation levels can influence glucose uptake, cell growth, and adhesion in the protozoan parasite C. fasciculata. PMID:24894907

Rojas, Robert; Segovia, Christopher; Trombert, Annette Nicole; Santander, Javier; Manque, Patricio

2014-10-01

227

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

PubMed Central

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

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

228

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

SciTech Connect

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.

Sturtevant, J.E.

1985-01-01

229

Hsp60 is targeted to a cryptic mitochondrion-derived organelle ("crypton") in the microaerophilic protozoan parasite Entamoeba histolytica.  

PubMed

Entamoeba histolytica is a microaerophilic protozoan parasite in which neither mitochondria nor mitochondrion-derived organelles have been previously observed. Recently, a segment of an E. histolytica gene was identified that encoded a protein similar to the mitochondrial 60-kDa heat shock protein (Hsp60 or chaperonin 60), which refolds nuclear-encoded proteins after passage through organellar membranes. The possible function and localization of the amebic Hsp60 were explored here. Like Hsp60 of mitochondria, amebic Hsp60 RNA and protein were both strongly induced by incubating parasites at 42 degreesC. 5' and 3' rapid amplifications of cDNA ends were used to obtain the entire E. histolytica hsp60 coding region, which predicted a 536-amino-acid Hsp60. The E. histolytica hsp60 gene protected from heat shock Escherichia coli groEL mutants, demonstrating the chaperonin function of the amebic Hsp60. The E. histolytica Hsp60, which lacked characteristic carboxy-terminal Gly-Met repeats, had a 21-amino-acid amino-terminal, organelle-targeting presequence that was cleaved in vivo. This presequence was necessary to target Hsp60 to one (and occasionally two or three) short, cylindrical organelle(s). In contrast, amebic alcohol dehydrogenase 1 and ferredoxin, which are bacteria-like enzymes, were diffusely distributed throughout the cytosol. We suggest that the Hsp60-associated, mitochondrion-derived organelle identified here be named "crypton," as its structure was previously hidden and its function is still cryptic. PMID:10022906

Mai, Z; Ghosh, S; Frisardi, M; Rosenthal, B; Rogers, R; Samuelson, J

1999-03-01

230

Hsp60 Is Targeted to a Cryptic Mitochondrion-Derived Organelle ("Crypton") in the Microaerophilic Protozoan Parasite Entamoeba histolytica  

PubMed Central

Entamoeba histolytica is a microaerophilic protozoan parasite in which neither mitochondria nor mitochondrion-derived organelles have been previously observed. Recently, a segment of an E. histolytica gene was identified that encoded a protein similar to the mitochondrial 60-kDa heat shock protein (Hsp60 or chaperonin 60), which refolds nuclear-encoded proteins after passage through organellar membranes. The possible function and localization of the amebic Hsp60 were explored here. Like Hsp60 of mitochondria, amebic Hsp60 RNA and protein were both strongly induced by incubating parasites at 42°C. 5? and 3? rapid amplifications of cDNA ends were used to obtain the entire E. histolytica hsp60 coding region, which predicted a 536-amino-acid Hsp60. The E. histolytica hsp60 gene protected from heat shock Escherichia coli groEL mutants, demonstrating the chaperonin function of the amebic Hsp60. The E. histolytica Hsp60, which lacked characteristic carboxy-terminal Gly-Met repeats, had a 21-amino-acid amino-terminal, organelle-targeting presequence that was cleaved in vivo. This presequence was necessary to target Hsp60 to one (and occasionally two or three) short, cylindrical organelle(s). In contrast, amebic alcohol dehydrogenase 1 and ferredoxin, which are bacteria-like enzymes, were diffusely distributed throughout the cytosol. We suggest that the Hsp60-associated, mitochondrion-derived organelle identified here be named “crypton,” as its structure was previously hidden and its function is still cryptic. PMID:10022906

Mai, Zhiming; Ghosh, Sudip; Frisardi, Marta; Rosenthal, Ben; Rogers, Rick; Samuelson, John

1999-01-01

231

Introduction of Caveolae Structural Proteins into the Protozoan Toxoplasma Results in the Formation of Heterologous Caveolae but Not Caveolar Endocytosis  

PubMed Central

Present on the plasma membrane of most metazoans, caveolae are specialized microdomains implicated in several endocytic and trafficking mechanisms. Caveolins and the more recently discovered cavins are the major protein components of caveolae. Previous studies reported that caveolar invaginations can be induced de novo on the surface of caveolae-negative mammalian cells upon heterologous expression of caveolin-1. However, it remains undocumented whether other components in the transfected cells participate in caveolae formation. To address this issue, we have exploited the protozoan Toxoplasma as a heterologous expression system to provide insights into the minimal requirements for caveogenesis and caveolar endocytosis. Upon expression of caveolin-1, Toxoplasma accumulates prototypical exocytic caveolae ‘precursors’ in the cytoplasm. Toxoplasma expressing caveolin-1 alone, or in conjunction with cavin-1, neither develops surface-located caveolae nor internalizes caveolar ligands. These data suggest that the formation of functional caveolae at the plasma membrane in Toxoplasma and, by inference in all non-mammalian cells, requires effectors other than caveolin-1 and cavin-1. Interestingly, Toxoplasma co-expressing caveolin-1 and cavin-1 displays an impressive spiraled network of membranes containing the two proteins, in the cytoplasm. This suggests a synergistic activity of caveolin-1 and cavin-1 in the morphogenesis and remodeling of membranes, as illustrated for Toxoplasma. PMID:23272165

Lige, Bao; Sonda, Sabrina; Joiner, Keith A.; Coppens, Isabelle

2012-01-01

232

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

PubMed

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

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

233

Picomonas judraskeda Gen. Et Sp. Nov.: The First Identified Member of the Picozoa Phylum Nov., a Widespread Group of Picoeukaryotes, Formerly Known as 'Picobiliphytes'  

PubMed Central

In 2007, a novel, putatively photosynthetic picoeukaryotic lineage, the ‘picobiliphytes’, with no known close eukaryotic relatives, was reported from 18S environmental clone library sequences and fluorescence in situ hybridization. Although single cell genomics later showed these organisms to be heterotrophic rather than photosynthetic, until now this apparently widespread group of pico-(or nano-)eukaryotes has remained uncultured and the organisms could not be formally recognized. Here, we describe Picomonas judraskeda gen. et sp. nov., from marine coastal surface waters, which has a ‘picobiliphyte’ 18S rDNA signature. Using vital mitochondrial staining and cell sorting by flow cytometry, a single cell-derived culture was established. The cells are biflagellate, 2.5–3.8×2–2.5 µm in size, lack plastids and display a novel stereotypic cycle of cell motility (described as the “jump, drag, and skedaddle”-cycle). They consist of two hemispherical parts separated by a deep cleft, an anterior part that contains all major cell organelles including the flagellar apparatus, and a posterior part housing vacuoles/vesicles and the feeding apparatus, both parts separated by a large vacuolar cisterna. From serial section analyses of cells, fixed at putative stages of the feeding cycle, it is concluded that cells are not bacterivorous, but feed on small marine colloids of less than 150 nm diameter by fluid-phase, bulk flow endocytosis. Based on the novel features of cell motility, ultrastructure and feeding, and their isolated phylogenetic position, we establish a new phylum, Picozoa, for Picomonas judraskeda, representing an apparently widespread and ecologically important group of heterotrophic picoeukaryotes, formerly known as ‘picobiliphytes’. PMID:23555709

Seenivasan, Ramkumar; Sausen, Nicole; Medlin, Linda K.; Melkonian, Michael

2013-01-01

234

Microbial Community Analysis in the Roots of Aquatic Plants and Isolation of Novel Microbes Including an Organism of the Candidate Phylum OP10  

PubMed Central

A number of molecular ecological studies have revealed complex and unique microbial communities in various terrestrial plant roots; however, little is known about the microbial communities of aquatic plant roots in spite of their potential use for water quality improvement in aquatic environments (e.g. floating treatment wetland system). Here, we report the microbial communities inhabiting the roots of emerged plants, reed (Phragmites australis) and Japanese loosestrife (Lythrum anceps), collected from a floating treatment wetland in a pond by both culture-independent and culture-dependent approaches. Culture-independent analysis based on 16S rRNA gene sequences revealed that the microbial compositions between the two aquatic plant roots were clearly different (e.g. the predominant microbe was Betaproteobacteria for reed and Alphaproteobacteria for Japanese loosestrife). In comparisons of microbial communities between the plant roots and pond water taken from near the plants, the microbial diversity in the plant roots (e.g. 4.40–4.26 Shannon-Weiner index) were higher than that of pond water (e.g. 3.15 Shannon-Weiner index). Furthermore, the plant roots harbored 2.5–3.5 times more phylogenetically novel clone phylotypes than pond water. The culture-dependent approach also revealed differences in the microbial composition and diversity among the two plant roots and pond water. More importantly, compared to pond water, we succeeded in isolating approximately two times more novel isolate phylotypes, including a bacterium of candidate phylum OP10 (recently named Armatimonadetes) from the plant roots. These findings suggest that aquatic plants roots are significant sources for a variety of novel organisms. PMID:22791047

Tanaka, Yasuhiro; Tamaki, Hideyuki; Matsuzawa, Hiroaki; Nigaya, Masahiro; Mori, Kazuhiro; Kamagata, Yoichi

2012-01-01

235

Nitrososphaera viennensis gen. nov., sp. nov., an aerobic and mesophilic, ammonia-oxidizing archaeon from soil and a member of the archaeal phylum Thaumarchaeota.  

PubMed

A mesophilic, neutrophilic and aerobic, ammonia-oxidizing archaeon, strain EN76(T), was isolated from garden soil in Vienna (Austria). Cells were irregular cocci with a diameter of 0.6-0.9 µm and possessed archaella and archaeal pili as cell appendages. Electron microscopy also indicated clearly discernible areas of high and low electron density, as well as tubule-like structures. Strain EN76(T) had an S-layer with p3 symmetry, so far only reported for members of the Sulfolobales. Crenarchaeol was the major core lipid. The organism gained energy by oxidizing ammonia to nitrite aerobically, thereby fixing CO2, but growth depended on the addition of small amounts of organic acids. The optimal growth temperature was 42 °C and the optimal pH was 7.5, with ammonium and pyruvate concentrations of 2.6 and 1 mM, respectively. The genome of strain EN76(T) had a DNA G+C content of 52.7 mol%. Phylogenetic analyses of 16S rRNA genes showed that strain EN76(T) is affiliated with the recently proposed phylum Thaumarchaeota, sharing 85% 16S rRNA gene sequence identity with the closest cultivated relative 'Candidatus Nitrosopumilus maritimus' SCM1, a marine ammonia-oxidizing archaeon, and a maximum of 81% 16S rRNA gene sequence identity with members of the phyla Crenarchaeota and Euryarchaeota and any of the other recently proposed phyla (e.g. 'Korarchaeota' and 'Aigarchaeota'). We propose the name Nitrososphaera viennensis gen. nov., sp. nov. to accommodate strain EN76(T). The type strain of Nitrososphaera viennensis is strain EN76(T) (?=?DSM 26422(T)?=?JMC 19564(T)). Additionally, we propose the family Nitrososphaeraceae fam. nov., the order Nitrososphaerales ord. nov. and the class Nitrososphaeria classis nov. PMID:24907263

Stieglmeier, Michaela; Klingl, Andreas; Alves, Ricardo J E; Rittmann, Simon K-M R; Melcher, Michael; Leisch, Nikolaus; Schleper, Christa

2014-08-01

236

Terrimicrobium sacchariphilum gen. nov., sp. nov., an anaerobic bacterium of the class 'Spartobacteria' in the phylum Verrucomicrobia, isolated from a rice paddy field.  

PubMed

A strictly anaerobic, mesophilic, carbohydrate-fermenting bacterium, designated NM-5T, was isolated from a rice paddy field. Cells of strain NM-5(T) were Gram-stain-negative, non-motile, non-spore-forming, short rods (0.5-0.7 µm×0.6-1.2 µm). The strain grew optimally at 37 °C (growth range 20-40 °C) and pH 7.0 (pH 5.5-8.0). The strain could grow fermentatively on arabinose, xylose, fructose, galactose, glucose, ribose, mannose, cellobiose, lactose, maltose and sucrose. The main end-products of glucose fermentation were acetate and propionate. Organic acids, alcohols and amino acids were not utilized for growth. Yeast extract was not required but stimulated the growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite, and Fe (III) nitrilotriacetate were not used as terminal electron acceptors. The DNA G+C content was 46.3 mol%. The major cellular fatty acids were iso-C14:0, C18:0 and C16:0. 16S rRNA gene sequence analysis revealed that strain NM-5T belongs to the class 'Spartobacteria', subdivision 2 of the bacterial phylum Verrucomicrobia. Phylogenetically, the closest species was 'Chthoniobacter flavus' (89.6% similarity in 16S rRNA gene sequence). A novel genus and species, Terrimicrobium sacchariphilum gen. nov., sp. nov., is proposed. The type strain of the type species is NM-5T (=JCM 17479T=CGMCC 1.5168T). PMID:24535138

Qiu, Yan-Ling; Kuang, Xiao-zhu; Shi, Xiao-shuang; Yuan, Xian-zheng; Guo, Rong-bo

2014-05-01

237

Oligosphaera ethanolica gen. nov., sp. nov., an anaerobic, carbohydrate-fermenting bacterium isolated from methanogenic sludge, and description of Oligosphaeria classis nov. in the phylum Lentisphaerae.  

PubMed

A mesophilic, obligately anaerobic, carbohydrate-fermenting bacterium, designated 8KG-4(T), was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from salted vegetable production processes. Cells of strain 8KG-4(T) were non-motile, spherical and 0.7-1.5 µm in diameter (mean, 1.0 µm). Spore formation was not observed under any culture conditions tested. The strain grew optimally at 37 °C (range for growth 25-40 °C) and pH 7.0 (range, pH 6.5-7.5), and could grow fermentatively on glucose, ribose, xylose, galactose and sucrose. The main end products of glucose fermentation were acetate, ethanol and hydrogen. Organic acids, alcohols and amino acids were not utilized for growth. Yeast extract was not required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe(III) nitrilotriacetate were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.1 mol%. 16S rRNA gene sequence analysis revealed that the isolate represented a previously uncultured lineage at the subphylum level within the phylum Lentisphaerae known as 'WWE2 subgroup I'. The major cellular fatty acids were anteiso-C(15?:?0), iso-C(16?:?0), C(16?:?0) and anteiso-C(17?:?0). Respiratory quinones were not detected. The most abundant polar lipid of strain 8KG-4(T) was phosphatidylethanolamine. A novel genus and species, Oligosphaera ethanolica gen. nov., sp. nov., is proposed to accommodate strain 8KG-4(T) (?=?JCM 17152(T)?=?DSM 24202(T) ?=?CGMCC 1.5160(T)). In addition, we formally propose Oligosphaeria classis nov. and the subordinate taxa Oligosphaerales order nov. and Oligosphaeraceae fam. nov. PMID:22523166

Qiu, Yan-Ling; Muramatsu, Mizuho; Hanada, Satoshi; Kamagata, Yoichi; Guo, Rong-Bo; Sekiguchi, Yuji

2013-02-01

238

The Ascomycota tree of life: a phylum-wide phylogeny clarifies the origin and evolution of fundamental reproductive and ecological traits.  

PubMed

We present a 6-gene, 420-species maximum-likelihood phylogeny of Ascomycota, the largest phylum of Fungi. This analysis is the most taxonomically complete to date with species sampled from all 15 currently circumscribed classes. A number of superclass-level nodes that have previously evaded resolution and were unnamed in classifications of the Fungi are resolved for the first time. Based on the 6-gene phylogeny we conducted a phylogenetic informativeness analysis of all 6 genes and a series of ancestral character state reconstructions that focused on morphology of sporocarps, ascus dehiscence, and evolution of nutritional modes and ecologies. A gene-by-gene assessment of phylogenetic informativeness yielded higher levels of informativeness for protein genes (RPB1, RPB2, and TEF1) as compared with the ribosomal genes, which have been the standard bearer in fungal systematics. Our reconstruction of sporocarp characters is consistent with 2 origins for multicellular sexual reproductive structures in Ascomycota, once in the common ancestor of Pezizomycotina and once in the common ancestor of Neolectomycetes. This first report of dual origins of ascomycete sporocarps highlights the complicated nature of assessing homology of morphological traits across Fungi. Furthermore, ancestral reconstruction supports an open sporocarp with an exposed hymenium (apothecium) as the primitive morphology for Pezizomycotina with multiple derivations of the partially (perithecia) or completely enclosed (cleistothecia) sporocarps. Ascus dehiscence is most informative at the class level within Pezizomycotina with most superclass nodes reconstructed equivocally. Character-state reconstructions support a terrestrial, saprobic ecology as ancestral. In contrast to previous studies, these analyses support multiple origins of lichenization events with the loss of lichenization as less frequent and limited to terminal, closely related species. PMID:20525580

Schoch, Conrad L; Sung, Gi-Ho; López-Giráldez, Francesc; Townsend, Jeffrey P; Miadlikowska, Jolanta; Hofstetter, Valérie; Robbertse, Barbara; Matheny, P Brandon; Kauff, Frank; Wang, Zheng; Gueidan, Cécile; Andrie, Rachael M; Trippe, Kristin; Ciufetti, Linda M; Wynns, Anja; Fraker, Emily; Hodkinson, Brendan P; Bonito, Gregory; Groenewald, Johannes Z; Arzanlou, Mahdi; de Hoog, G Sybren; Crous, Pedro W; Hewitt, David; Pfister, Donald H; Peterson, Kristin; Gryzenhout, Marieka; Wingfield, Michael J; Aptroot, André; Suh, Sung-Oui; Blackwell, Meredith; Hillis, David M; Griffith, Gareth W; Castlebury, Lisa A; Rossman, Amy Y; Lumbsch, H Thorsten; Lücking, Robert; Büdel, Burkhard; Rauhut, Alexandra; Diederich, Paul; Ertz, Damien; Geiser, David M; Hosaka, Kentaro; Inderbitzin, Patrik; Kohlmeyer, Jan; Volkmann-Kohlmeyer, Brigitte; Mostert, Lizel; O'Donnell, Kerry; Sipman, Harrie; Rogers, Jack D; Shoemaker, Robert A; Sugiyama, Junta; Summerbell, Richard C; Untereiner, Wendy; Johnston, Peter R; Stenroos, Soili; Zuccaro, Alga; Dyer, Paul S; Crittenden, Peter D; Cole, Mariette S; Hansen, Karen; Trappe, James M; Yahr, Rebecca; Lutzoni, François; Spatafora, Joseph W

2009-04-01

239

Phylum: Tardigrada (water bears, tardigrades)  

NSDL National Science Digital Library

This web page describes water bears, minute animals that can remain dormant in a dry state for over 100 years. The page addresses what they are, where they are found, their general biology, cryptobiosis, their ability to resist environmental extremes, implications and further research regarding their cryptobiosis, where they fit in with other animals, and their existence in South Africa. It also describes how someone could collect and see them. The page is part of Biodiversity Explorer, a web site hosted by Iziko Museums of Cape Town that features the diversity of life in South Africa.

Middleton, Roger; Town, Iziko M.

240

IgG antibody responses in mice coinfected with Toxocara canis and other helminths or protozoan parasites.  

PubMed

The immune response expressed by IgG antibodies in BALB/c mice experimentally infected with Toxocara canis, was studied with the aim of verifying the possible in vivo cross-reactivity between antigens of T. canis and other parasites (Ascaris suum, Taenia crassiceps, Schistosoma mansoni, Strongyloides venezuelensis and Toxoplasma gondii). Experiments included three groups of mice: one infected only by T. canis, another with one of the other species of parasites and a third concomitantly infected with T. canis and the other species in question. Animals were bled by orbital plexus at 23, 38 and 70 days post infection (p.i.). Sera were analyzed for anti-Toxocara antibodies by ELISA and Immunoblotting, using excretion-secretion antigens (ES), obtained from culture of third-stage larvae of T. canis. For all experiments a control group comprised by ten non-infected mice was used. Only in the case of A. suum infection, in these experimental conditions, the occurrence of cross-reactivity with T. canis was observed. However, in the case of co-infection of T. canis - S. mansoni, T. canis - S. venezuelensis and T. canis - T. crassiceps the production of anti-Toxocara antibodies was found at levels significantly lower than those found in mice infected with T. canis only. Co-infection with S. mansoni or S. venezuelensis showed lower mortality rates compared to what occurred in the animals with single infections. Results obtained in mice infected with T. canis and T. gondii showed significant differences between the mean levels of the optical densities of animals infected with T. canis and concomitantly infected with the protozoan only in the 23rd day p.i. PMID:22634886

Lescano, Susana A Zevallos; Nakhle, Maria Cristina; Ribeiro, Manoel Carlos S A; Chieffi, Pedro Paulo

2012-01-01

241

Rapid Escape of the dot/icm Mutants of Legionella pneumophila into the Cytosol of Mammalian and Protozoan Cells? †  

PubMed Central

The Legionella pneumophila-containing phagosome evades endocytic fusion and intercepts endoplasmic reticulum (ER)-to-Golgi vesicle traffic, which is believed to be mediated by the Dot/Icm type IV secretion system. Although phagosomes harboring dot/icm mutants are thought to mature through the endosomal-lysosomal pathway, colocalization studies with lysosomal markers have reported contradictory results. In addition, phagosomes harboring the dot/icm mutants do not interact with endocytosed materials, which is inconsistent with maturation of the phagosomes in the endosomal-lysosomal pathway. Using multiple strategies, we show that the dot/icm mutants defective in the Dot/Icm structural apparatus are unable to maintain the integrity of their phagosomes and escape into the cytoplasm within minutes of entry into various mammalian and protozoan cells in a process independent of the type II secretion system. In contrast, mutants defective in cytoplasmic chaperones of Dot/Icm effectors and rpoS, letA/S, and letE regulatory mutants are all localized within intact phagosomes. Importantly, non-dot/icm L. pneumophila mutants whose phagosomes acquire late endosomal-lysosomal markers are all located within intact phagosomes. Using high-resolution electron microscopy, we show that phagosomes harboring the dot/icm transporter mutants do not fuse to lysosomes but are free in the cytoplasm. Inhibition of ER-to-Golgi vesicle traffic by brefeldin A does not affect the integrity of the phagosomes harboring the parental strain of L. pneumophila. We conclude that the Dot/Icm transporter is involved in maintaining the integrity of the L. pneumophila phagosome, independent of interception of ER-to-Golgi vesicle traffic, which is a novel function of type IV secretion systems. PMID:17438033

Molmeret, Maelle; Santic', Marina; Asare, Rexford; Carabeo, Reynold A.; Kwaik, Yousef Abu

2007-01-01

242

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

PubMed

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

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

2013-02-01

243

Detection and localization of a putative cyclic-GMP-activated channel protein in the protozoan ciliate Stentor coeruleus.  

PubMed

Immunoblotting and immunocytochemical assays were employed to identify and localize a channel protein activated by cyclic GMP (cGMP) in the protozoan ciliate Stentor coeruleus. Analysis of whole-cell homogenate with antibodies raised against the alpha-subunit of the cGMP-activated channel protein from bovine rod outer segments and against cGMP revealed four major protein bands with molecular masses of 40 kDa, 63 kDa, and over 120 kDa, which bound cGMP. However, only a cGMP-binding protein of 63 kDa, corresponding to the alpha-subunit of the cGMP-activated ion channel protein from bovine rod outer segments, was found in the ciliate cortex fraction. The functional cGMP-activated channel protein was also shown to be present in the cortex fraction of S. coeruleus by patch-clamp measurements of artificial liposomes. Incorporation of the cortex fraction into liposomes resulted in the appearance of ion channel activity related to cGMP. The reconstituted protein channels were strongly inhibited by l-cis-diltiazem, a known potent blocker of many types of cyclic-nucleotide-activated channels. The results presented here are the first demonstration of the existence and localization of a putative cGMP-activated channel protein in the ciliate S. coeruleus. Cyclic-nucleotide-activated channel proteins are nonspecific cation channels which mediate the receptor potentials in photoreceptor cells and in cells of the olfactory epithelium. On the basis of these data, we suggest that the 63 kDa protein identified in Stentor coeruleus is also a cGMP-activated ion channel and that it may be involved as an effector in the photosensory transduction pathway leading to the motile photophobic response in this ciliate protist. PMID:16736256

Walerczyk, M; Fabczak, H; Fabczak, S

2006-05-01

244

Seasonal dynamics of phytoplankton and planktonic protozoan communities in a northern temperate humic lake: diversity in a dinoflagellate dominated system.  

PubMed

Species diversity and richness, and seasonal population dynamics of phytoplankton, planktonic protozoa, and bacterioplankton sampled from the epilimnion of Crystal Bog in 2000, were examined in order to test the hypothesis that these groups' diversity and abundance patterns might be linked. Crystal Bog, a humic lake in Vilas County, Wisconsin, is part of the North Temperate Lakes Long-Term Ecological Research Site. Phytoplankton and planktonic protozoa were identified and enumerated in a settling chamber with an inverted microscope. Bacterial cells were enumerated with the use of fluorescence 4', 6'-diamidino-2-phenylindole (DAPI)-staining procedures, and automated ribosomal intergenic spacer analysis (ARISA) was used to assess bacterioplankton diversity. Bacterial cell counts showed little seasonal variation and averaged 2.6 x 10(6) cells/mL over the ice-free season. Phytoplankton and planktonic protozoan numbers varied by up to two orders of magnitude and were most numerous in late spring and summer. Dinoflagellates largely dominated Crystal Bog throughout the ice-free period, specifically Peridiniopsis quadridens in the spring, Peridinium limbatum in summer, and Gymnodinium fuscum and P. quadridens in fall. Brief blooms of Cryptomonas, Dinobryon, and Synura occurred between periods of dinoflagellate domination. The dominant dinoflagellate, Peridinium limbatum, was calculated to have a growth rate of 0.065 day(-1) and a doubling time of 10.7 days. Heterotrophic nanoflagellates (HNFs) were a consistent component of the planktonic protozoa; seasonal patterns were determined for three genera of HNFs (Monosiga, Bicosoeca, and Desmarella moniliformis). Three genera of ciliates (Coleps, Strobilidium, and Strombidium) comprised the greater part of the planktonic protozoa in Crystal Bog. The number of species of planktonic protozoa was too low to calculate a diversity index. Shannon-Weaver diversity indices for phytoplankton and bacterioplankton in the epilimnion followed very similar seasonal patterns in this lake, supporting the hypothesis that in freshwaters, diversity patterns of these groups are linked. PMID:15696386

Graham, J M; Kent, A D; Lauster, G H; Yannarell, A C; Graham, L E; Triplett, E W

2004-11-01

245

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

PubMed

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 × 10(4) cells/well), linearity (R (2) = 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

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

2013-12-01

246

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

PubMed Central

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

Shridhar, Surekha; Hassan, Kolaleh; Sullivan, David J.; Vasta, Gerardo R.; Fernandez Robledo, Jose A.

2013-01-01

247

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

PubMed Central

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

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

2012-01-01

248

Lactivibrio alcoholicus gen. nov., sp. nov., an anaerobic, mesophilic, lactate-, alcohol-, carbohydrate- and amino-acid-degrading bacterium in the phylum Synergistetes.  

PubMed

A mesophilic, obligately anaerobic, lactate-, alcohol-, carbohydrate- and amino-acid- degrading bacterium, designated strain 7WAY-8-7(T), was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from isomerized sugar production processes. Cells of strain 7WAY-8-7(T) were motile, curved rods (0.7-1.0×5.0-8.0 µm). Spore formation was not observed. The strain grew optimally at 37 °C (range for growth was 25-40 °C) and pH 7.0 (pH 6.0-7.5), and could grow fermentatively on yeast extract, glucose, ribose, xylose, malate, tryptone, pyruvate, fumarate, Casamino acids, serine and cysteine. The main end-products of glucose fermentation were acetate and hydrogen. In co-culture with the hydrogenotrophic methanogen Methanospirillum hungatei DSM 864(T), strain 7WAY-8-7(T) could utilize lactate, glycerol, ethanol, 1-propanol, 1-butanol, L-glutamate, alanine, leucine, isoleucine, valine, histidine, asparagine, glutamine, arginine, lysine, threonine, 2-oxoglutarate, aspartate and methionine. A Stickland reaction was not observed with some pairs of amino acids. Yeast extract was required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe (III) were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.4 mol%. 16S rRNA gene sequence analysis revealed that the isolate belongs to the uncultured environmental clone clade (called 'PD-UASB-13' in the Greengenes database) in the bacterial phylum Synergistetes, showing less than 90% sequence similarity with closely related described species such as Aminivibrio pyruvatiphilus and Aminobacterium colombiense (89.7% and 88.7%, respectively). The major cellular fatty acids were iso-C(13?:?0), iso-C(15?:?0), anteiso-C(15?:?0), C(18?:?1), C(19?:?1), C(20?:?1) and C(21?:?1). A novel genus and species, Lactivibrio alcoholicus gen. nov., sp. nov. is proposed to accommodate strain 7WAY-8-7(T) (?=?JCM 17151(T)?=?DSM 24196(T)?=?CGMCC 1.5159(T)). PMID:24676730

Qiu, Yan-Ling; Hanada, Satoshi; Kamagata, Yoichi; Guo, Rong-Bo; Sekiguchi, Yuji

2014-06-01

249

Extrachromosomal DNA in the Apicomplexa.  

PubMed Central

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

Wilson, R J; Williamson, D H

1997-01-01

250

Altered Protozoan and Bacterial Communities and Survival of Escherichia coli O157:H7 in Monensin-Treated Wastewater from a Dairy Lagoon  

PubMed Central

Surviving predation is a fitness trait of Escherichia coli O157:H7 (EcO157) that provides ample time for the pathogen to be transported from reservoirs (e.g. dairies and feedlots) to farm produce grown in proximity. Ionophore dietary supplements that inhibit rumen protozoa may provide such a selective advantage for EcO157 to proliferate in lagoons as the pathogen is released along with the undigested supplement as manure washings. This study evaluated the fate of an outbreak strain of EcO157, protozoan and bacterial communities in wastewater treated with monensin. Although total protozoa and native bacteria were unaffected by monensin, the time for 90% decrease in EcO157 increased from 0.8 to 5.1 days. 18S and 16S rRNA gene sequencing of wastewater samples revealed that monensin eliminated almost all colpodean and oligohymenophorean ciliates, probably facilitating the extended survival of EcO157. Total protozoan numbers remained high in treated wastewater as monensin enriched 94% of protozoan sequences undetected with untreated wastewater. Monensin stimulated 30-fold increases in Cyrtohymena citrina, a spirotrichean ciliate, and also biflagellate bicosoecids and cercozoans. Sequences of gram-negative Proteobacteria increased from 1% to 46% with monensin, but gram-positive Firmicutes decreased from 93% to 46%. It is noteworthy that EcO157 numbers increased significantly (P<0.01) in Sonneborn medium containing monensin, probably due to monensin-inhibited growth of Vorticella microstoma (P<0.05), a ciliate isolated from wastewater. We conclude that dietary monensin inhibits ciliate protozoa that feed on EcO157. Feed supplements or other methods that enrich these protozoa in cattle manure could be a novel strategy to control the environmental dissemination of EcO157 from dairies to produce production environments. PMID:23349969

Ravva, Subbarao V.; Sarreal, Chester Z.; Mandrell, Robert E.

2013-01-01

251

Metabolism of inositol phosphates in the protozoan Paramecium. Characterization of a novel inositol-hexakisphosphate-dephosphorylating enzyme.  

PubMed

Basal and stimulated levels of inositol phosphates were determined in the protozoan Paramecium labelled with myo-[3H]inositol. Under resting conditions, intracellular InsP6 (phytic acid), InsP5 and InsP4 concentrations were 140, 10 and 2 microM, respectively. InsP5 was comprised of 56% Ins(1,2,3,4,5)P5 and/or Ins(1,2,3,5,6)P5, 40% Ins(1,2,4,5,6)P5 and/or Ins(2,3,4,5,6)P5 and small amounts of Ins(1,3,4,5,6)P5 and Ins(1,2,3,4,6)P5. InsP4 was mainly Ins(1, 4, 5, 6)P4 and/or Ins(3, 4, 5, 6)P4. Other inositol phosphates were not detected at a detection limit of 50-85 nM. Using various depolarizing and hyperpolarizing stimuli, no significant changes in level of inositol phosphates were observed in vivo, indicating that in the ciliate a contribution of inositol phosphates to signal-transduction mechanisms is unlikely. In homogenates prepared from myo-[3H]inositol-labelled cells, a marked relative increase in InsP3 and InsP4 over the concentrations in vivo was observed. These inositol phosphates were identified as degradation products of endogenous InsP6. A novel separation methodology for inositol phosphates was established to allow unequivocal assignment of phosphate locations of all dephosphorylated InsP6-derived products. The dephosphorylation was catalyzed by a phytase-like enzyme with a molecular mass of 240 kDa, most likely of a hexameric structure. The enzyme had a pH optimum of 7.0 and did not require divalent cations for activity. Substrate concentrations above 300 microM were inhibitory. Dephosphorylation of InsP6 by the Paramecium enzyme differs from that of phytases from plants in that it proceeds via a sequential release of phosphate groups from positions 6, 5, 4 and 3 of the myo-inositol ring or/and positions 4, 5, 6 and 1. PMID:1628659

Freund, W D; Mayr, G W; Tietz, C; Schultz, J E

1992-07-01

252

High-resolution genotyping and mapping of recombination and gene conversion in the protozoan Theileria parva using whole genome sequencing  

PubMed Central

Background Theileria parva is a tick-borne protozoan parasite, which causes East Coast Fever, a disease of cattle in sub-Saharan Africa. Like Plasmodium falciparum, the parasite undergoes a transient diploid life-cycle stage in the gut of the arthropod vector, which involves an obligate sexual cycle. As assessed using low-resolution VNTR markers, the crossover (CO) rate in T. parva is relatively high and has been reported to vary across different regions of the genome; non-crossovers (NCOs) and CO-associated gene conversions have not yet been characterised due to the lack of informative markers. To examine all recombination events at high marker resolution, we sequenced the haploid genomes of two parental strains, and two recombinant clones derived from ticks fed on cattle that had been simultaneously co-infected with two different parasite isolates. Results By comparing the genome sequences, we were able to genotype over 64 thousand SNP markers with an average spacing of 127 bp in the two progeny clones. Previously unrecognized COs in sub-telomeric regions were detected. About 50% of CO breakpoints were accompanied by gene conversion events. Such a high fraction of COs accompanied by gene conversions demonstrated the contributions of meiotic recombination to the diversity and evolutionary success of T. parva, as the process not only redistributed existing genetic variations, but also altered allelic frequencies. Compared to COs, NCOs were more frequently observed and more uniformly distributed across the genome. In both progeny clones, genomic regions with more SNP markers had a reduced frequency of COs or NCOs, suggesting that the sequence divergence between the parental strains was high enough to adversely affect recombination frequencies. Intra-species polymorphism analysis identified 81 loci as likely to be under selection in the sequenced genomes. Conclusions Using whole genome sequencing of two recombinant clones and their parents, we generated maps of COs, NCOs, and CO-associated gene conversion events for T. parva. The data comprises one of the highest-resolution genome-wide analyses of the multiple outcomes of meiotic recombination for this pathogen. The study also demonstrates the usefulness of high throughput sequencing typing for detailed analysis of recombination in organisms in which conventional genetic analysis is technically difficult. PMID:22998600

2012-01-01

253

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

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

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

254

Effect of aeration on pollutants removal, biofilm activity and protozoan abundance in conventional and hybrid horizontal subsurface-flow constructed wetlands.  

PubMed

The large area demand of constructed wetlands (CWs) is documented as a weak point that can be potentially reduced by applying active aeration. The aim of this study was, therefore, to understand the effects of aeration on the treatment performance, the biofilm activity, the protozoan population size and potential CW footprint reduction of different horizontal flow (HF) CW configurations. Two experimental periods were considered: a first period with low organic loading rate (OLR) and a second period with high OLR. Three HF CW configurations were compared: a conventional (control), an aerated and a hybrid CW (aerated followed by a non-aerated CW). The results obtained reinforced the competence of aerated CW for organic matter removal (81-89% of chemical oxygen demand) while for nitrogen elimination the control (19-24%) and hybrid (8-41%) systems performed better than the aerated system (-6% to 33%). Biofilm activity and protozoa abundance were distinctly higher at the inlet zones when compared with the outlet zones of all CWs, as well as in the aerated systems when compared with the non-aerated CWs. The protozoan abundance increased with an increase in the OLR and ciliates were found to be the dominant group. Overall, the active aeration highlighted the efficiency and stability of the CWs for organic matter removal and thus can be used as a promising tool to enhance microbial activity and grazing by protozoa; eventually reducing solid accumulation in the bed media. These beneficial effects contribute to reduce the CWs' area requirements. PMID:24956803

Zapater-Pereyra, M; Gashugi, E; Rousseau, D P L; Alam, M R; Bayansan, T; Lens, P N L

2014-08-01

255

Comparison between Quantitative Buffy Coat (QBC) and Giemsa-stained Thin Film (GTF) technique for blood protozoan infections in wild rats.  

PubMed

The quantitative buffy coat (QBC) technique and conventional Giemsa thin blood smear was compared to determine the sensitivity and specificity of the technique in detecting blood parasitic infection of the rodent populations from four urban cities in Peninsular Malaysia. A total of 432 blood samples from four rat species (Rattus norvegicus, Rattus rattus diardii, Rattus exulans and Rattus argentiventer) were screened using both techniques and successfully detected two blood protozoan species (Trypanosoma lewisi and Plasmodium sp.) with Trypanosoma lewisi predominantly infecting the population. Results showed that Giemsa-stained thin film (GTF) was the better detection method on blood parasitemia (46.7%) compared to Quantitative Buffy Coat method (38.9%) with overall detection technique sensitivity and specificity at 83.2% and 74.8% respectively. The sensitivity in detection of Trypanosoma lewisi was 84.4% with value slightly lower for Plasmodium sp. infections at 76.6%. Statistical analysis proved that GTF technique was significantly more sensitive in the detection of blood protozoan infections in the rodent population compared to QBC (p<0.05). PMID:25382468

Sahimin, N; Alias, S N; Woh, P Y; Edah, M A; Mohd Zain, S N

2014-09-01

256

Prevalence of a protozoan parasite Cristigera sp. (Ciliophora:Ciliatea) from edible oysters (Mollusca:Bivalvia) of Sundarbans, West Bengal, India.  

PubMed

The coastal region of West Bengal is bestowed with a wide range of natural forest and aquatic resources. The estuarine complex is a culmination of the interaction of land, sea and freshwater. It offers diverse specialised habitats such as mangroves, non vegetated mudflats, inter tidal zones and reclaimed areas. Such areas are home to a number of terrestrial, freshwater and marine communities. Edible oyster resources in these regions are Crassostrea gryphoides and Saccostrea cucullata, which are the keystone species found in the intertidal zone and can tolerate huge variation of salinity. These are used as food by local people and marketed to earn cash. The population of this species has been declined due to parasitic infection and pollution. There are many protozoan parasites which infect these oysters causing diseases. During survey period, a protozoan parasite of the genus Cristigera have been observed only from the edible oyster Crassostrea gryphoides collected from Kaikhali and Frasergunj among three selected sites namely Kaikhali, Frasergunj and Digha of West Bengal mainly during monsoon and post-monsoon season. Considering such rare and specific prevalence of Cristigera sp, it may be considered as potential bio-indicator. PMID:25035589

Biswas, Tanima; Bandyopadhyay, Probir Kumar

2014-09-01

257

The structural organization of the pathogenic protozoan Tritrichomonas foetus as seen in replicas of quick frozen, freeze-fractured and deep etched cells.  

PubMed

The quick-freezing and freeze-etching technique was used to analyse the cytoskeleton of Tritrichomonas foetus, a pathogenic protozoan of the urogenital tract of cattle. The cytoplasm presented a network of filamentous structures interacting with each other, with the surface of the hydrogenosomes and the nuclear membrane. Two nm wide filamentous structures were found in the luminal space of the Golgi complex, connecting the two faces of each cisterna. The microtubules of the pelta-axostyle system were connected by bridges 30-40 nm long and 10 nm wide, regularly spaced with an interval of 25 nm. The costa is a structure formed by a complex array of filaments and globous structures. It seems to be connected to the recurrent flagellum through a complex network formed by 15 and 10 nm wide filaments which emerge from the peripheral region of the costa and penetrate into the surface projections of the protozoan body to which the recurrent flagellum is attached. Other filaments were seen connecting the surface of these projections with the surface of the flagellum. PMID:8401293

Benchimol, M; Kachar, B; de Souza, W

1993-01-01

258

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

PubMed

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

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

2006-01-01

259

An inside job: hacking into Janus kinase/signal transducer and activator of transcription signaling cascades by the intracellular protozoan Toxoplasma gondii.  

PubMed

The intracellular protozoan Toxoplasma gondii is well known for its skill at invading and living within host cells. New discoveries are now also revealing the astounding ability of the parasite to inject effector proteins into the cytoplasm to seize control of the host cell. This review summarizes recent advances in our understanding of one such secretory protein called ROP16. This molecule is released from rhoptries into the host cell during invasion. The ROP16 molecule acts as a kinase, directly activating both signal transducer and activator of transcription 3 (STAT3) and STAT6 signaling pathways. In macrophages, an important and preferential target cell of parasite infection, the injection of ROP16 has multiple consequences, including downregulation of proinflammatory cytokine signaling and macrophage deviation to an alternatively activated phenotype. PMID:22104110

Denkers, Eric Y; Bzik, David J; Fox, Barbara A; Butcher, Barbara A

2012-02-01

260

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

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.

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

261

Composite genome map and recombination parameters derived from three archetypal lineages of Toxoplasma gondii  

PubMed Central

Toxoplasma gondii is a highly successful protozoan parasite in the phylum Apicomplexa, which contains numerous animal and human pathogens. T.gondii is amenable to cellular, biochemical, molecular and genetic studies, making it a model for the biology of this important group of parasites. To facilitate forward genetic analysis, we have developed a high-resolution genetic linkage map for T.gondii. The genetic map was used to assemble the scaffolds from a 10X shotgun whole genome sequence, thus defining 14 chromosomes with markers spaced at ?300 kb intervals across the genome. Fourteen chromosomes were identified comprising a total genetic size of ?592 cM and an average map unit of ?104 kb/cM. Analysis of the genetic parameters in T.gondii revealed a high frequency of closely adjacent, apparent double crossover events that may represent gene conversions. In addition, we detected large regions of genetic homogeneity among the archetypal clonal lineages, reflecting the relatively few genetic outbreeding events that have occurred since their recent origin. Despite these unusual features, linkage analysis proved to be effective in mapping the loci determining several drug resistances. The resulting genome map provides a framework for analysis of complex traits such as virulence and transmission, and for comparative population genetic studies. PMID:15911631

Khan, Asis; Taylor, Sonya; Su, Chunlei; Mackey, Aaron J.; Boyle, Jon; Cole, Robert; Glover, Darius; Tang, Keliang; Paulsen, Ian T.; Berriman, Matt; Boothroyd, John C.; Pfefferkorn, Elmer R.; Dubey, J. P.; Ajioka, James W.; Roos, David S.; Wootton, John C.; Sibley, L. David

2005-01-01

262

Prevalence of Sarcocystis spp. and Hammondia spp. microcysts in esophagus tissue of sheep and cattle, emphasized on their morphological differences.  

PubMed

Sarcocystis and Hammondia are two obligatory protozoan parasites. These genera belong to cyst-forming coccidia group of the phylum Apicomplexa. They both need two different hosts to complete their life cycles. Felids and canids can act as definitive hosts, while herbivores, such as sheep and cattle, are the most important intermediate hosts. Reports verify that no important disease has been caused by Hammondia spp.; on the other hand, Sarcocystis spp. can cause some severe infectious disease in livestock industry such as abortion. Economic losses are another concern due to carcass condemnation during meat inspection in abattoirs and decrease in the quality and quantity of milk and wool production. Due to the Sarcocystis and Hammondia tissue cysts being similar, the distinction between these different genera is so important. In this study, the prevalence of Sarcocystis and Hammondia in the esophagus tissue of sheep and cattle slaughtered in one of the industrial abattoir in Iran was reported and an easy and rapid method for accurate diagnosing of Sarcocystis and Hammondia bradyzoites was explained. PMID:25082016

Rassouli, Maryam; Ahmadpanahi, Javad; Alvandi, Ayda

2014-10-01

263

Cytokine and chemokine responses to helminth and protozoan parasites and to fungus and mite allergens in neonates, children, adults, and the elderly  

PubMed Central

Background In rural sub-Saharan Africa, endemic populations are often infected concurrently with several intestinal and intravascular helminth and protozoan parasites. A specific, balanced and, to an extent, protective immunity will develop over time in response to repeated parasite encounters, with immune responses initially being poorly adapted and non-protective. The cellular production of pro-inflammatory and regulatory cytokines and chemokines in response to helminth, protozoan antigens and ubiquitous allergens were studied in neonates, children, adults and the elderly. Results In children schistosomiasis prevailed (33%) while hookworm and Entamoeba histolytica/E. dispar was found in up to half of adults and the elderly. Mansonella perstans filariasis was only present in adults (24%) and the elderly (25%). Two or more parasite infections were diagnosed in 41% of children, while such polyparasitism was present in 34% and 38% of adults and the elderly. Cytokine and chemokine production was distinctively inducible by parasite antigens; pro-inflammatory Th2-type cytokine IL-19 was activated by Entamoeba and Ascaris antigens, being low in neonates and children while IL-19 production enhanced “stepwise” in adults and elderly. In contrast, highest production of MIP-1delta/CCL15 was present in neonates and children and inducible by Entamoeba-specific antigens only. Adults and the elderly had enhanced regulatory IL-27 cytokine responses, with Th2-type chemokines (MCP-4/CCL13, Eotaxin-2/CCL24) and cytokines (IL-33) being notably inducible by helminth- and Entamoeba-specific antigens and fungus-derived allergens. The lower cellular responsiveness in neonates and children highlighted the development of a parasite-specific cellular response profile in response to repeated episodes of exposure and re-infection. Conclusions Following repeated exposure to parasites, and as a consequence of host inability to prevent or eliminate intestinal helminth or protozoa infections, a repertoire of immune responses will evolve with lessened pro-inflammatory and pronounced regulatory cytokines and chemokines; this is required for partial parasite control as well as for preventing inadequate and excessive host tissue and organ damage. PMID:23855879

2013-01-01

264

Characterization of a cDNA encoding a cysteine-rich cell surface protein located in the flagellar pocket of the protozoan Trypanosoma brucei.  

PubMed Central

We have characterized a cDNA encoding a cysteine-rich, acidic integral membrane protein (CRAM) of the parasitic protozoa Trypanosoma brucei and Trypanosoma equiperdum. Unlike other membrane proteins of T. brucei, which are distributed throughout the cell surface, CRAM is concentrated in the flagellar pocket, an invagination of the cell surface of the trypanosome where endocytosis has been documented. Accordingly, CRAM also locates to vesicles located underneath the pocket, providing evidence of its internalization. CRAM has a predicted molecular mass of 130 kilodaltons and has a signal peptide, a transmembrane domain, and a 41-amino-acid cytoplasmic extension. A characteristic feature of CRAM is a large extracellular domain with a roughly 66-fold acidic, cysteine-rich 12-amino-acid repeat. CRAM is conserved among different protozoan species, including Trypanosoma cruzi, and CRAM has structural similarities with eucaryotic cell surface receptors. The most striking homology of CRAM is to the human low-density-lipoprotein receptor. We propose that CRAM functions as a cell surface receptor of different trypanosome species. Images PMID:1697030

Lee, M G; Bihain, B E; Russell, D G; Deckelbaum, R J; Van der Ploeg, L H

1990-01-01

265

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

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

Peckham, R. K.; Brill, R.; Foster, D. S.; Bowen, A. L.; Leigh, J. A.; Coffey, T. J.; Flynn, R. J.

2014-01-01

266

Current Therapeutics, Their Problems, and Sulfur-Containing-Amino-Acid Metabolism as a Novel Target against Infections by "Amitochondriate" Protozoan Parasites  

PubMed Central

The “amitochondriate” protozoan parasites of humans Entamoeba histolytica, Giardia intestinalis, and Trichomonas vaginalis share many biochemical features, e.g., energy and amino acid metabolism, a spectrum of drugs for their treatment, and the occurrence of drug resistance. These parasites possess metabolic pathways that are divergent from those of their mammalian hosts and are often considered to be good targets for drug development. Sulfur-containing-amino-acid metabolism represents one such divergent metabolic pathway, namely, the cysteine biosynthetic pathway and methionine ?-lyase-mediated catabolism of sulfur-containing amino acids, which are present in T. vaginalis and E. histolytica but absent in G. intestinalis. These pathways are potentially exploitable for development of drugs against amoebiasis and trichomoniasis. For instance, l-trifluoromethionine, which is catalyzed by methionine ?-lyase and produces a toxic product, is effective against T. vaginalis and E. histolytica parasites in vitro and in vivo and may represent a good lead compound. In this review, we summarize the biology of these microaerophilic parasites, their clinical manifestation and epidemiology of disease, chemotherapeutics, the modes of action of representative drugs, and problems related to these drugs, including drug resistance. We further discuss our approach to exploit unique sulfur-containing-amino-acid metabolism, focusing on development of drugs against E. histolytica. PMID:17223627

Ali, Vahab; Nozaki, Tomoyoshi

2007-01-01

267

In Vitro Antiproliferative Effects and Mechanism of Action of the New Triazole Derivative UR-9825 against the Protozoan Parasite Trypanosoma (Schizotrypanum) cruzi  

PubMed Central

We describe the in vitro antiproliferative effects of the new triazole derivative UR-9825 against the protozoan parasite Trypanosoma (Schizotrypanum) cruzi, the causative agent of Chagas' disease in Latin America. The compound was found to be extremely active against the cultured (epimastigote) form of the parasite, equivalent to that present in the reduviid vector, with a MIC of 30 nM, a concentration 33-fold lower than that required with the reference compound ketoconazole. At that MIC, growth arrest coincided with depletion of the parasite's 4,14-desmethyl endogenous sterols (ergosterol, 24-ethylcholesta-5,7,22-trien-3b-ol, and precursors) and their replacement by methylated sterols (lanosterol, 24-methylenedihydrolanosterol, and obtusifoliol), as revealed by high-resolution gas chromatography coupled with mass spectrometry. This indicated that the primary mechanism of action of UR-9825 was inhibition of the parasite's sterol C14? demethylase, as seen with other azole derivatives. The phospholipid composition of growth-arrested epimastigotes was also altered, when compared to controls, with a significant increase in the content of phosphatidylethanolamine and phosphatidylserine and a concomitant reduction of the content of phosphatidylcholine. The clinically relevant intracellular amastigote form, grown in cultured Vero cells at 37°C, was even more sensitive to UR-9825, with a MIC of 10 nM, comparable to that for ketoconazole. The results showed that UR-9825 is among the most potent azole derivatives tested against this parasite and support in vivo studies with this compound. PMID:10952601

Urbina, Julio A.; Lira, Renee; Visbal, Gonzalo; Bartroli, Javier

2000-01-01

268

Whole proteome analysis of the protozoan parasite Trypanosoma brucei using stable isotope labeling by amino acids in cell culture and mass spectrometry.  

PubMed

The single-celled protozoan Trypanosoma brucei spp. is the causative agent of human African trypanosomiasis and nagana in cattle. Quantitative proteomics for the first time has allowed for the characterization of the proteome from several different life stages of the parasite (Butter et al., Mol Cell Proteomics 12:172-179, 2013; Gunasekera et al., BMC Genomics 13:556, 2012; Urbaniak et al., PloS One 7(5):e36619, 2012). To achieve this, stable isotope labeling by amino acids in cell culture (SILAC) (Ong et al., Mol Cell Proteomics 1:376-386, 2002) was adapted to T. brucei spp. cultures. T. brucei cells grown in standard media with dialyzed fetal calf serum containing heavy isotope-labeled amino acids (arginine and lysine) show efficient incorporation of the labeled amino acids into the whole cell proteome (8-12 divisions) and no detectable amino acid conversions. The method can be applied to both of the major life stages of the parasite and in combination with RNAi or gene knockout approaches. PMID:25059603

Cirovic, Olivera; Ochsenreiter, Torsten

2014-01-01

269

A Systematic Screen to Discover and Analyze Apicoplast Proteins Identifies a Conserved and Essential Protein Import Factor  

Microsoft Academic Search

Parasites of the phylum Apicomplexa cause diseases that impact global health and economy. These unicellular eukaryotes possess a relict plastid, the apicoplast, which is an essential organelle and a validated drug target. However, much of its biology remains poorly understood, in particular its elaborate compartmentalization: four membranes defining four different spaces. Only a small number of organellar proteins have been

Lilach Sheiner; Jessica L. Demerly; Nicole Poulsen; Wandy L. Beatty; Olivier Lucas; Michael S. Behnke; Michael W. White; Boris Striepen

2011-01-01

270

Zoonotic babesiosis: Overview of the disease and novel aspects of pathogen identity  

Microsoft Academic Search

Babesiosis is a zoonosis caused by tick-transmitted intraerythrocytic protozoa of the Phylum Apicomplexa. The disease mostly occurs in the USA, but cases have also been reported in several European countries, in Egypt, India, Japan, Korea, Taiwan, and South Africa. The main pathological event is lysis of erythrocytes resulting in haemolytic anaemia, which in severe cases may lead to organ failure

Jeremy Gray; Annetta Zintl; Anke Hildebrandt; Klaus-Peter Hunfeld; Louis Weiss

2010-01-01

271

BiochemicalSocietyAnnualSymposiumNo.77 Malaria, Plasmodium falciparum and its  

E-print Network

BiochemicalSocietyAnnualSymposiumNo.77 Malaria, Plasmodium falciparum and its apicoplast Ming, Australia Abstract Malaria, which is caused by species of the parasite genus Plasmodium, remains a major was discovered in malaria and related parasites from the phylum Apicomplexa and has radically changed our view

McFadden, Geoff

272

Isolation and characterization of Thermanaerothrix daxensis gen. nov., sp. nov., a thermophilic anaerobic bacterium pertaining to the phylum "Chloroflexi", isolated from a deep hot aquifer in the Aquitaine Basin.  

PubMed

A new strictly anaerobic thermophilic multicellular filamentous bacterium (0.2-0.3?m×>100?m), designated GNS-1(T), was isolated from a deep hot aquifer in France. It was non-motile, and stained Gram-negative. Optimal growth was observed at 65°C, pH 7.0, and 2gL(-1) of NaCl. Strain GNS-1(T) was chemoorganotrophic fermenting ribose, glucose, galactose, arabinose, fructose, mannose, maltose, sucrose, xylose, raffinose, pyruvate, and xylan. Yeast extract was required for growth. The end products of glucose fermentation were lactate, acetate, CO(2), and H(2). The G+C content of the DNA was 57.6mol%. Its closest phylogenetic relative was Bellilinea caldifistulae with 92.5% similarity. Based on phylogenetic, genotypic and phenotypic characteristics, strain GNS-1(T) (DSM 23592(T), JCM 16980(T)) is proposed to be assigned to a novel species of a novel genus within the class Anaerolineae (subphylum I), phylum "Chloroflexi", Thermanaerothrix daxensis gen. nov., sp. nov. The GenBank accession number is HM596746. PMID:21621938

Grégoire, Patrick; Fardeau, Marie-Laure; Joseph, Manon; Guasco, Sophie; Hamaide, Francette; Biasutti, Sandra; Michotey, Valérie; Bonin, Patricia; Ollivier, Bernard

2011-11-01

273

Mass Spectrometric Analysis of l-Cysteine Metabolism: Physiological Role and Fate of l-Cysteine in the Enteric Protozoan Parasite Entamoeba histolytica  

PubMed Central

ABSTRACT l-Cysteine is essential for virtually all living organisms, from bacteria to higher eukaryotes. Besides having a role in the synthesis of virtually all proteins and of taurine, cysteamine, glutathione, and other redox-regulating proteins, l-cysteine has important functions under anaerobic/microaerophilic conditions. In anaerobic or microaerophilic protozoan parasites, such as Entamoeba histolytica, l-cysteine has been implicated in growth, attachment, survival, and protection from oxidative stress. However, a specific role of this amino acid or related metabolic intermediates is not well understood. In this study, using stable-isotope-labeled l-cysteine and capillary electrophoresis-time of flight mass spectrometry, we investigated the metabolism of l-cysteine in E. histolytica. [U-13C3, 15N]l-cysteine was rapidly metabolized into three unknown metabolites, besides l-cystine and l-alanine. These metabolites were identified as thiazolidine-4-carboxylic acid (T4C), 2-methyl thiazolidine-4-carboxylic acid (MT4C), and 2-ethyl-thiazolidine-4-carboxylic acid (ET4C), the condensation products of l-cysteine with aldehydes. We demonstrated that these 2-(R)-thiazolidine-4-carboxylic acids serve for storage of l-cysteine. Liberation of l-cysteine occurred when T4C was incubated with amebic lysates, suggesting enzymatic degradation of these l-cysteine derivatives. Furthermore, T4C and MT4C significantly enhanced trophozoite growth and reduced intracellular reactive oxygen species (ROS) levels when it was added to cultures, suggesting that 2-(R)-thiazolidine-4-carboxylic acids are involved in the defense against oxidative stress. PMID:25370494

Jeelani, Ghulam; Sato, Dan; Soga, Tomoyoshi; Watanabe, Haruo

2014-01-01

274

Metabolome Analysis Revealed Increase in S-Methylcysteine and Phosphatidylisopropanolamine Synthesis upon l-Cysteine Deprivation in the Anaerobic Protozoan Parasite Entamoeba histolytica*  

PubMed Central

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

Husain, Afzal; Sato, Dan; Jeelani, Ghulam; Mi-ichi, Fumika; Ali, Vahab; Suematsu, Makoto; Soga, Tomoyoshi; Nozaki, Tomoyoshi

2010-01-01

275

Puniceicoccus vermicola gen. nov., sp. nov., a novel marine bacterium, and description of Puniceicoccaceae fam. nov., Puniceicoccales ord. nov., Opitutaceae fam. nov., Opitutales ord. nov. and Opitutae classis nov. in the phylum 'Verrucomicrobia'.  

PubMed

A Gram-negative, chemoheterotrophic, facultatively anaerobic coccus, designated IMCC1545(T), was isolated from the digestive tract of a marine clamworm, Periserrula leucophryna, inhabiting a tidal flat of the Yellow Sea. Cells of strain IMCC1545(T) are non-motile, dividing by binary fission. The predominant fatty acids are anteiso-C(15 : 0) and C(18 : 0). The respiratory quinone is menaquinone-7 and the DNA G+C content is 52.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences using three treeing algorithms revealed that the strain formed a novel genus-level lineage within the phylum 'Verrucomicrobia'. The most closely related named organisms to strain IMCC1545(T) are 'Fucophilus fucoidanolyticus' SI-1234 (86.5 % 16S rRNA gene sequence similarity), Alterococcus agarolyticus ADT3(T) (81.8 %) and Opitutus terrae PB90-1(T) (80.3 %), which belong to subdivision 4 of the 'Verrucomicrobia'. Subdivision 4 of the 'Verrucomicrobia' (here named Opitutae classis nov.) was divided into two clades, a clade containing strain IMCC1545(T) and a clade containing Opitutus terrae. 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 Puniceicoccus vermicola gen. nov., sp. nov. (the type strain of Puniceicoccus vermicola is IMCC1545(T)=KCCM 42343(T)=NBRC 101964(T)) within Puniceicoccaceae fam. nov and Puniceicoccales ord. nov in the class Opitutae. The family Opitutaceae fam. nov. and order Opitutales ord. nov. are also formally proposed. PMID:17329779

Choo, Yoe-Jin; Lee, Kiyoung; Song, Jaeho; Cho, Jang-Cheon

2007-03-01

276

Apoptotic markers in protozoan parasites  

Microsoft Academic Search

The execution of the apoptotic death program in metazoans is characterized by a sequence of morphological and biochemical changes that include cell shrinkage, presentation of phosphatidylserine at the cell surface, mitochondrial alterations, chromatin condensation, nuclear fragmentation, membrane blebbing and the formation of apoptotic bodies. Methodologies for measuring apoptosis are based on these markers. Except for membrane blebbing and formation of

Antonio Jiménez-Ruiz; Juan Fernando Alzate; Ewan Thomas MacLeod; Carsten Günter Kurt Lüder; Nicolas Fasel; Hilary Hurd

2010-01-01

277

INTRODUCTION The phylum Platyhelminthes (flatworms) consists of  

E-print Network

sexual and asexual strategies for their reproduction (Brusca and Brusca, 1990; Hyman, 1951). Yet completely from small body fragments has been known for over two centuries (Morgan, 1898; Randolph, 1897, asexual form of the planarian Schmidtea mediterranea (Turbellaria, Tricladida), along with the isolation

Alvarado, Alejandro Sánchez

278

Living with the enemy or uninvited guests: functional genomics approaches to investigating host resistance or tolerance traits to a protozoan parasite, Theileria annulata, in cattle.  

PubMed

Many breeds of cattle with long histories of living in areas of endemic disease have evolved mechanisms that enable them to co-exist with specific pathogens. Understanding the genes that control tolerance and resistance could provide new strategies to improve the health and welfare of livestock. Around one sixth of the world cattle population is estimated to be at risk from one of the most debilitating tick-borne diseases of cattle, caused by the protozoan parasite, Theileria annulata. The parasite mainly infects cells of the myeloid lineage which are also the main producers of inflammatory cytokines. If an infectious or inflammatory insult is sufficiently great, inflammatory cytokines produced by macrophages enter the circulation and induce an acute phase proteins (APP) response. The Bos taurus Holstein breed produces higher and more prolonged levels of inflammatory cytokine induced APP than the Bos indicus Sahiwal breed in response to experimental infection with T. annulata. The Sahiwal exhibits significantly less pathology and survives infection, unlike the Holstein breed. Therefore, we hypothesised that the causal genes were likely to be expressed in macrophages and control the production of inflammatory cytokines. A functional genomics approach revealed that the transcriptome profile of the B. taurus macrophages was more associated with an inflammatory programme than the B. indicus macrophages. In particular the most differentially expressed gene was a member of the signal regulatory protein (SIRP) family. These are mainly expressed on myeloid cell surfaces and control inflammatory responses. Other differentially expressed genes included bovine major histocompatibility complex (MHC) (BoLA) class II genes, particularly BoLA DQ, and transforming growth factor (TGF)B2. We are now exploring whether sequence and functional differences in the bovine SIRP family may underlie the resistance or tolerance to T. annulata between the breeds. Potentially, our research may also have more general implications for the control of inflammatory processes against other pathogens. Genes controlling the balance between pathology and protection may determine how livestock can survive in the face of infectious onslaught. Next generation sequencing and RNAi methodologies for livestock species will bring new opportunities to link diversity at the genome level to functional differences in health traits in livestock species. PMID:22482839

Glass, Elizabeth J; Crutchley, Sarah; Jensen, Kirsty

2012-07-15

279

Activities of the Triazole Derivative SCH 56592 (Posaconazole) against Drug-Resistant Strains of the Protozoan Parasite Trypanosoma (Schizotrypanum) cruzi in Immunocompetent and Immunosuppressed Murine Hosts  

PubMed Central

We have studied the in vivo activity of the new experimental triazole derivative SCH 56592 (posaconazole) against a variety of strains of the protozoan parasite Trypanosoma (Schizotrypanum) cruzi, the causative agent of Chagas' disease, in both immunocompetent and immunosuppressed murine hosts. The T. cruzi strains used in the study were previously characterized as susceptible (CL), partially resistant (Y), or highly resistant (Colombiana, SC-28, and VL-10) to the drugs currently in clinical use, nifurtimox and benznidazole. Furthermore, all strains are completely resistant to conventional antifungal azoles, such as ketoconazole. In the first study, acute infections with the CL, Y, and Colombiana strains in both normal and cyclophosphamide-immunosuppressed mice were treated orally, starting 4 days postinfection (p.i.), for 20 consecutive daily doses. The results indicated that in immunocompetent animals SCH 56592 at 20 mg/kg of body weight/day provided protection (80 to 90%) against death caused by all strains, a level comparable or superior to that provided by the optimal dose of benznidazole (100 mg/kg/day). Evaluation of parasitological cure revealed that SCH 56592 was able to cure 90 to 100% of the surviving animals infected with the CL and Y strains and 50% of those which received the benznidazole- and nifurtimox-resistant Colombiana strain. Immunosuppression markedly reduced the mean survival time of untreated mice infected with any of the strains, but this was not observed for the groups which received SCH 56592 at 20 mg/kg/day or benznidazole at 100 mg/kg/day. However, the overall cure rates were higher for animals treated with SCH 56592 than among those treated with benznidazole. The results were confirmed in a second study, using the same model but a longer (43-dose) treatment period. Finally, a model for the chronic disease in which oral treatment was started 120 days p.i. and consisted of 20 daily consecutive doses was investigated. The results showed that SCH 56592 at 20 mg/kg/day was able to induce a statistically significant increase in survival of animals infected with all strains, while benznidazole at 100 mg/kg/day was able to increase survival only in animals infected with the Colombiana strain. Moreover, the triazole was able to induce parasitological cures in 50 to 60% of surviving animals, irrespective of the infecting strain, while no cures were obtained with benznidazole. Taken together, the results demonstrate that SCH 56592 has in vivo trypanocidal activity, even against T. cruzi strains naturally resistant to nitrofurans, nitroimidazoles, and conventional antifungal azoles, and that this activity is retained to a large extent in immunosuppressed hosts. PMID:10602737

Molina, Judith; Martins-Filho, Olindo; Brener, Zigman; Romanha, Alvaro J.; Loebenberg, David; Urbina, Julio A.

2000-01-01

280

Haemoproteus (Apicomplexa: Haemoproteidae) of tortoises and turtles.  

PubMed Central

It is the general opinion that the haemoproteid blood parasites of chelonians belong to the genus Haemoproteus. Different specific names have long been assigned to this parasite in birds, but some past authorities have accepted only a single species, H. metchnikovi, for all those haemoproteids recorded in a wide range of chelonian genera throughout the world. In the present study, a comparison of one such organism in the tortoise Geochelone denticulata with another in the river turtle Peltocephalus dumerilianus, from Amazonian Brazil, has revealed clear morphological differences. These distinguish the parasites from each other, H. metchnikovi and the other named species of chelonian Haemoproteus for which adequate descriptions are available. We have assigned to them the names Haemoproteus geochelonis n.sp. and Haemoproteus peltocephali n.sp. PMID:9675908

Lainson, R; Naiff, R D

1998-01-01

281

Divergent polyamine metabolism in the Apicomplexa.  

PubMed

The lead enzymes of polyamine biosynthesis, i.e. ornithine decarboxylase (ODC) and arginine decarboxylase (ADC), were not detected in Toxoplasma gondii [the limit of detection for ODC and ADC was 5 pmol min(-1) (mg protein)(-1)], indicating that T. gondii lacks a forward-directed polyamine biosynthetic pathway, and is therefore a polyamine auxotroph. The biochemical results were supported by results obtained from data-mining the T. gondii genome. However, it was possible to demonstrate the presence of a highly active backconversion pathway that formed spermidine from spermine, and putrescine from spermidine, via the combined action of spermidine/spermine N(1)-acetyltransferase (SSAT) or spermidine N(1)-acetyltransferase (SAT) and polyamine oxidase (PAO). With spermine as the substrate, T. gondii SSAT had a specific activity of 1.84 nmol min(-1) (mg protein)(-1), and an apparent K(m) for spermine of 180 mM; with spermidine as the substrate, the SAT had a specific activity of 3.95 nmol min(-1) (mg protein)(-1), and a K(m) for spermidine of 240 mM. T. gondii PAO had a specific activity of 10.6 nmol min(-1) (mg protein)(-1), and a K(m) for acetylspermine of 36 mM. Furthermore, the results demonstrated that T. gondii SSAT was 50 % inhibited by 30 mM di(ethyl)norspermine. The parasite actively transported arginine and ornithine, which were converted via the arginine dihydrolase pathway to citrulline and carbamoyl phosphate, resulting in the formation of ATP via carbamate kinase. The lack of polyamine biosynthesis by T. gondii is contrasted with polyamine metabolism by other apicomplexans. PMID:17379721

Cook, Tuesday; Roos, David; Morada, Mary; Zhu, Guan; Keithly, Janet S; Feagin, Jean E; Wu, Gang; Yarlett, Nigel

2007-04-01

282

Molecular signatures for the phylum (class) Thermotogae and a proposal for its division into three orders (Thermotogales, Kosmotogales ord. nov. and Petrotogales ord. nov.) containing four families (Thermotogaceae, Fervidobacteriaceae fam. nov., Kosmotogaceae fam. nov. and Petrotogaceae fam. nov.) and a new genus Pseudothermotoga gen. nov. with five new combinations.  

PubMed

All species from the phylum Thermotogae, class Thermotogae, are currently part of a single family, Thermotogaceae. Using genomic data from 17 Thermotogae species, detailed phylogenetic and comparative genomic analyses were carried out to understand their evolutionary relationships and identify molecular markers that are indicative of species relationships within the phylum. In the 16S rRNA gene tree and phylogenetic trees based upon two different large sets of proteins, members of the phylum Thermotogae formed a number of well-resolved clades. Character compatibility analysis on the protein sequence data also recovered a single largest clique that exhibited similar topology to the protein trees and where all nodes were supported by multiple compatible characters. Comparative genomic analyses have identified 85 molecular markers, in the form of conserved signature indels (CSIs), which are specific for different observed clades of Thermotogae at multiple phylogenetic depths. Eleven of these CSIs were specific for the phylum Thermotogae whereas nine others supported a clade comprising of the genera Thermotoga, Thermosipho and Fervidobacterium. Ten other CSIs provided evidence that the genera Thermosipho and Fervidobacterium shared a common ancestor exclusive of the other Thermotogae and four and eight CSIs in other proteins were specific for the genera Thermosipho and Fervidobacterium, respectively. Two other deep branching clades, one consisting of the genera Kosmotoga and Mesotoga and the other comprising of the genera Petrotoga and Marinitoga, were also supported by multiple CSIs. Based upon the consistent branching of the Thermotogae species using different phylogenetic approaches, and numerous identified CSIs supporting the distinctness of different clades, it is proposed that the class Thermotogae should be divided into three orders (Thermotogales, Kosmotogales ord. nov. and Petrotogales ord. nov.) containing four families (Thermotogaceae, Fervidobacteriaceae fam. nov., Kosmotogaceae fam. nov. and Petrotogaceae fam. nov.). Additionally, the results of our phylogenetic/compatibility studies along with the species distribution patterns of 22 identified CSIs, provide compelling evidence that the current genus Thermotoga is comprised of two evolutionary distinct groups and that it should be divided into two genera. It is proposed that the emended genus Thermotoga should retain only the species Thermotoga maritima, Tt. neapolitana, Tt. petrophila, Tt. naphthophila, Thermotoga sp. EMP, Thermotoga sp. A7A and Thermotoga sp. RQ2 while the other Thermotoga species (viz. Tt. lettingae, Tt. thermarum, Tt. elfii, Tt. subterranean and Tt. hypogea) be transferred to a new genus, Pseudothermotoga gen. nov. PMID:24166034

Bhandari, Vaibhav; Gupta, Radhey S

2014-01-01

283

Mice with a selective impairment of IFN-? signaling in macrophage lineage cells demonstrate the critical role of IFN-? activated macrophages for the control of protozoan parasitic infections in vivo1, 2  

PubMed Central

IFN-? has long been recognized as a cytokine with potent and varied effects in the immune response. While its effects on specific cell types have been well studied in vitro, its in vivo effects are less clearly understood because of its diverse actions on many different cell types. While control of multiple protozoan parasites is thought to depend critically on the direct action of IFN-? on macrophages, this premise has never been directly proven in vivo. In order to more directly examine the effects of IFN-? on cells of the macrophage lineage in vivo, we generated mice called the ‘Macrophages Insensitive to Interferon Gamma’ (MIIG) mice, which express a dominant negative mutant IFN-? receptor in CD68+ cells: monocytes, macrophages, dendritic cells, and mast cells. Macrophage lineage cells and mast cells from these mice are unable to respond to IFN-? while other cells are able to produce and respond to this cytokine normally. When challenged in vitro, macrophages from MIIG mice were unable produce NO or kill Trypanosoma cruzi or Leishmania major after priming with IFN-?. Furthermore, MIIG mice demonstrated impaired parasite control and heightened mortality after T. cruzi, L. major, and Toxoplasma gondii infection, despite an appropriate IFN-? response. In contrast, MIIG mice displayed normal control of lymphocytic choriomeningitis virus, despite persistent insensitivity of macrophages to IFN-?. Thus, the MIIG mouse formally demonstrates for the first time in vivo, the specific importance of direct, IFN-? mediated activation of macrophages for controlling infection with multiple protozoan parasites. “This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript. This version of the manuscript has not yet been copyedited or subjected to editorial proofreading by The JI; hence, it may differ from the final version published in The JI (online and in print). AAI (The JI) is not liable for errors or omissions in this author-produced version of the manuscript or in any version derived from it by the U.S. National Institutes of Health or any other third party. The final, citable version of record can be found at www.jimmunol.org.” PMID:20018611

Lykens, Jennifer E.; Terrell, Catherine E.; Zoller, Erin E.; Divanovic, Senad; Trompette, Aurelien; Karp, Christopher L.; Aliberti, Julio; Flick, Matthew J.; Jordan, Michael B.

2010-01-01

284

Lectin Binding Saccharides on a Parasitic Protozoan  

Microsoft Academic Search

Leishmania donovani promastigotes were specifically agglutinated by concanavalin A and phytohemagglutinin P. Somatic-somatic, flagellar-somatic, and flagellar-flagellar type agglutination was observed with the lectins. Enzyme-treated promastigotes gave reduced lectin agglutination reactions. The results suggest that complex saccharide moieties are randomly distributed on the surface of this organism.

Dennis M. Dwyer

1974-01-01

285

Use of protozoan communities for pollution monitoring.  

PubMed

A gradient of chronic organic pollution was identified in a small river in south-east England. The parasite fauna of the ubiquitous three-spined stickleback (Gasterosteus aculeatus L.) was studied at the extremes of the pollution gradient and trichodinid ciliates identified as a potential bioindicator. A simple technique was developed for the quantification of whole body-burdens of trichodinids on small fish. Three species of trichodinids were identified: Trichodina domerguei, T. tenuidens and Trichodinella epizootica at combined infestation intensities of < 14 to 137522/fish. Preliminary results are reported which may link the increased intensity of trichodinid infestation with increased concentration of sewage treatment works effluent. PMID:9802068

Yeomans, W E; Chubb, J C; Sweeting, R A

1997-09-01

286

Deuterostome phylogeny reveals monophyletic chordates and the new phylum Xenoturbellida  

Microsoft Academic Search

Deuterostomes comprise vertebrates, the related invertebrate chordates (tunicates and cephalochordates) and three other invertebrate taxa: hemichordates, echinoderms and Xenoturbella. The relationships between invertebrate and vertebrate deuterostomes are clearly important for understanding our own distant origins. Recent phylogenetic studies of chordate classes and a sea urchin have indicated that urochordates might be the closest invertebrate sister group of vertebrates, rather than

Sarah J. Bourlat; Thorhildur Juliusdottir; Christopher J. Lowe; Robert Freeman; Jochanan Aronowicz; Mark Kirschner; Eric S. Lander; Michael Thorndyke; Hiroaki Nakano; Andrea B. Kohn; Andreas Heyland; Leonid L. Moroz; Richard R. Copley; Maximilian J. Telford

2006-01-01

287

Phylum Arthropoda 1. Insecta, "Palaeoptera", pp. 184-186  

E-print Network

apomorphic of the Dicondylia Fig. 7.3 Insecta Key to major Hexapod groups Dicondylia - Zygentoma) First insects: Terrestrial or Aquatic? p.208 Tracheal system had to develop in air Key to major Hexapod

Wagner, Diane

288

Status and applications of echinoid (phylum echinodermata) toxicity test methods  

SciTech Connect

The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). The status and relative sensitivity of various test methods are described. The most frequently used test methods consist of short-term exposures of sea urchin sperm or embryos; these tests can be easily conducted at all times of the year by using species with complementary spawning cycles or laboratory conditioned populations of a single species. Data from reference toxicant and effluent toxicity tests are summarized. Information on the precision and sensitivity of echinoid test methods are limited and preclude rigorous comparisons with other test methods. The available data indicate that the sensitivity and precision of these methods are comparable to short-term chronic methods for other marine invertebrates and fish. Recent application of the sperm test in toxicity identification evaluations (TIEs) and studies of effluent toxicity decay and sediment toxicity illustrate the versatility of this rapid (10 to 60 min exposure) test method. Embryo tests typically use a 48 to 96 h exposure period and measure the occurrence of embryo malformations. Most recent applications of the embryo test have been for the assessment of sediment elutriate toxicity. Adult echinoderms are not frequently used to assess effluent or receiving water toxicity. Recent studies have had success in using the adult life stage of urchins and sand dollars to assess the effects of contaminated sediment on growth, behavior, and bioaccumulation.

Bay, S.; Burgess, R.; Nacci, D.

1993-01-01

289

Ribbon worm relationships: a phylogeny of the phylum Nemertea.  

PubMed Central

We present the most extensive phylogenetic analysis to date, to our knowledge, of higher-level nemertean relationships, based on sequence data from four different genes (the nuclear genes for nuclear large subunit rRNA (28S rRNA) and histone H3 (H3), and the mitochondrial genes for mitochondrial large subunit rRNA (16S rRNA) and cytochrome c oxidase subunit I (COI)). Well-supported clades are, in general, compatible with earlier, more limited, analyses, and current classification is largely in agreement with our results, although there are some notable exceptions. Bdellonemertea (represented by Malacobdella) is found to be a part of Monostilifera, and Polystilifera is the monophyletic sister group to Monostilifera. Cratenemertidae is the sister group to the remaining monostiliferans (including Malacobdella), a group to which we apply the new name Distromatonemertea. Heteronemertea is monophyletic and forms a clade with Hubrechtella; for this clade we introduce the name Pilidiophora. Finally, Pilidiophora and Hoplonemertea (with Malacobdella) form a monophyletic group, and we introduce the name Neonemertea to refer to this group. Palaeonemertea is found to be non-monophyletic and basal among nemerteans. PMID:12639321

Thollesson, Mikael; Norenburg, Jon L

2003-01-01

290

A QUICK REVIEW OF SCHISTOSOMES They are flatworms (Phylum  

E-print Network

vehicles, Lake Victoria, Kisumu, Kenya Giving your younger brother a bath - Ukerewe Island, Lake Victoria? Near Rio de Janeiro, Brazil Near Belo Horizonte,Brazil A stream in Kenya Lake Victoria, Tanzania #12

Loker, Eric "Sam"

291

Cryptosporidium erinacei n. sp. (Apicomplexa: Cryptosporidiidae) in hedgehogs.  

PubMed

The morphological, biological, and molecular characteristics of Cryptosporidium hedgehog genotype are described, and the species name Cryptosporidium erinacei n. sp. is proposed to reflect its specificity for hedgehogs under natural and experimental conditions. Oocysts of C. erinacei are morphologically indistinguishable from Cryptosporidium parvum, measuring 4.5-5.8 ?m (mean=4.9 ?m) × 4.0-4.8 ?m (mean=4.4 ?m) with a length to width ratio of 1.13 (1.02-1.35) (n=100). Oocysts of C. erinacei obtained from a naturally infected European hedgehog (Erinaceus europaeus) were infectious for naïve 8-week-old four-toed hedgehogs (Atelerix albiventris); the prepatent period was 4-5 days post infection (DPI) and the patent period was longer than 20 days. C. erinacei was not infectious for 8-week-old SCID and BALB/c mice (Mus musculus), Mongolian gerbils (Meriones unguiculatus), or golden hamsters (Mesocricetus auratus). Phylogenetic analyses based on small subunit rRNA, 60 kDa glycoprotein, actin, Cryptosporidium oocyst wall protein, thrombospondin-related adhesive protein of Cryptosporidium-1, and heat shock protein 70 gene sequences revealed that C. erinacei is genetically distinct from previously described Cryptosporidium species. PMID:24529828

Kvá?, Martin; Hofmannová, Lada; Hlásková, Lenka; Kv?to?ová, Dana; Vítovec, Ji?í; McEvoy, John; Sak, Bohumil

2014-03-17

292

Haemogregarina bigemina (Protozoa: Apicomplexa: Adeleorina) - past, present and future  

Microsoft Academic Search

This paper reviews past, current and likely future research on the fish haemogregarine, Haemogregarina bigemina Laveran et Mesnil, 1901. Recorded from 96 species of fishes, across 70 genera and 34 families, this broad distribution for H. bigemina is questioned. In its type hosts and other fishes, the parasite undergoes intraerythrocytic binary fission, finally forming mature paired gamonts. An intraleukocytic phase

Angela J. Davies; Nico J. Smit; Polly M. Hayes; Alan M. Seddon; David Wertheim

293

HOST SPECIFICITY OF CALYPTOSPORA FUNDULI (APICOMPLEXA: CALYPOTOSPORIDAE) IN ATHERINOFORM FISHES  

EPA Science Inventory

Calyptospora funduli has a broad host specificity, infecting at least 7 natural and 10 additional experimental definitive hosts, all atheriniform fishes within 5 families, but most in the genus Fundulus. arriers, apparently innate ones, prevent any development of C. funduli in pe...

294

Developmental biology of Cystoisospora (Apicomplexa: Sarcocystidae) monozoic tissue cysts.  

PubMed

Tissue cyst stages are an intriguing aspect of the developmental cycle and transmission of species of Sarcocystidae. Tissue-cyst stages of Toxoplasma, Hammondia, Neospora, Besnoitia, and Sarcocystis contain many infectious stages (bradyzoites). The tissue cyst stage of Cystoisospora (syn. Isospora) possesses only 1 infectious stage (zoite), and is therefore referred to as a monozoic tissue cyst (MZTC). No tissue cyst stages are presently known for members of Nephroisospora. The present report examines the developmental biology of MZTC stages of Cystoisospora Frenkel, 1977 . These parasites cause intestinal coccidiosis in cats, dogs, pigs, and humans. The MZTC stages of C. belli are believed to be associated with reoccurrence of clinical disease in humans. PMID:24841928

Lindsay, David S; Houk, Alice E; Mitchell, Sheila M; Dubey, J P

2014-08-01

295

Building the Perfect Parasite: Cell Division in Apicomplexa  

PubMed Central

Apicomplexans are pathogens responsible for malaria, toxoplasmosis, and crytposporidiosis in humans, and a wide range of livestock diseases. These unicellular eukaryotes are stealthy invaders, sheltering from the immune response in the cells of their hosts, while at the same time tapping into these cells as source of nutrients. The complexity and beauty of the structures formed during their intracellular development have made apicomplexans the darling of electron microscopists. Dramatic technological progress over the last decade has transformed apicomplexans into respectable genetic model organisms. Extensive genomic resources are now available for many apicomplexan species. At the same time, parasite transfection has enabled researchers to test the function of specific genes through reverse and forward genetic approaches with increasing sophistication. Transfection also introduced the use of fluorescent reporters, opening the field to dynamic real time microscopic observation. Parasite cell biologists have used these tools to take a fresh look at a classic problem: how do apicomplexans build the perfect invasion machine, the zoite, and how is this process fine-tuned to fit the specific niche of each pathogen in this ancient and very diverse group? This work has unearthed a treasure trove of novel structures and mechanisms that are the focus of this review. PMID:17604449

Striepen, Boris; Jordan, Carly N; Reiff, Sarah; van Dooren, Giel G

2007-01-01

296

The Life Cycle and Fitness of Gregarine (Apicomplexa)Parasites  

E-print Network

disease vectors, and impact of climate change, there has been increasing in- terest in such systems and animal that has been studied seriously has been shown to be parasitized by at least one, and often several, non-related species of protists, fungi, plants, or animals (Roberts and Janovy, 2009). Host

Logan, David

297

Lysine acetyltransferase GCN5b interacts with AP2 factors and is required for Toxoplasma gondii proliferation.  

PubMed

Histone acetylation has been linked to developmental changes in gene expression and is a validated drug target of apicomplexan parasites, but little is known about the roles of individual histone modifying enzymes and how they are recruited to target genes. The protozoan parasite Toxoplasma gondii (phylum Apicomplexa) is unusual among invertebrates in possessing two GCN5-family lysine acetyltransferases (KATs). While GCN5a is required for gene expression in response to alkaline stress, this KAT is dispensable for parasite proliferation in normal culture conditions. In contrast, GCN5b cannot be disrupted, suggesting it is essential for Toxoplasma viability. To further explore the function of GCN5b, we generated clonal parasites expressing an inducible HA-tagged dominant-negative form of GCN5b containing a point mutation that ablates enzymatic activity (E703G). Stabilization of this dominant-negative GCN5b was mediated through ligand-binding to a destabilization domain (dd) fused to the protein. Induced accumulation of the ddHAGCN5b(E703G) protein led to a rapid arrest in parasite replication. Growth arrest was accompanied by a decrease in histone H3 acetylation at specific lysine residues as well as reduced expression of GCN5b target genes in GCN5b(E703G) parasites, which were identified using chromatin immunoprecipitation coupled with microarray hybridization (ChIP-chip). Proteomics studies revealed that GCN5b interacts with AP2-domain proteins, apicomplexan plant-like transcription factors, as well as a "core complex" that includes the co-activator ADA2-A, TFIID subunits, LEO1 polymerase-associated factor (Paf1) subunit, and RRM proteins. The dominant-negative phenotype of ddHAGCN5b(E703G) parasites, considered with the proteomics and ChIP-chip data, indicate that GCN5b plays a central role in transcriptional and chromatin remodeling complexes. We conclude that GCN5b has a non-redundant and indispensable role in regulating gene expression required during the Toxoplasma lytic cycle. PMID:24391497

Wang, Jiachen; Dixon, Stacy E; Ting, Li-Min; Liu, Ting-Kai; Jeffers, Victoria; Croken, Matthew M; Calloway, Myrasol; Cannella, Dominique; Hakimi, Mohamed Ali; Kim, Kami; Sullivan, William J

2014-01-01

298

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

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

Leung, Jacqueline M.; Tran, Fanny; Pathak, Ravindra B.; Poupart, Severine; Heaslip, Aoife T.; Ballif, Bryan A.; Westwood, Nicholas J.; Ward, Gary E.

2014-01-01

299

Cryptosporidium parvum appears to lack a plastid genome.  

PubMed

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

Zhu, G; Marchewka, M J; Keithly, J S

2000-02-01

300

Investigation into the transplacental transmission of Encephalitozoon cuniculi in rabbits  

Microsoft Academic Search

Summary An investigation into the transmission of Encephalito- zoon cuniculi was undertaken in both naturally- and experimentally-infected rabbits. Only 2 nurslings were found with rising antibody titres at 8-10 weeks of age, when infection could have been caused by environmental contamination. Encephalitozoon cuniculi is a protozoan of the Phylum Microsporidia (Sprague, 1977) and was first discovered by Levaditi, Nicolau &

Dawn G. Owen; J. Gannon

1980-01-01

301

The Alveolate Perkinsus marinus: Biological Insights from EST Gene Discovery  

Microsoft Academic Search

BACKGROUND: Perkinsus marinus, a protozoan parasite of the eastern oyster Crassostrea virginica, has devastated natural and farmed oyster populations along the Atlantic and Gulf coasts of the United States. It is classified as a member of the Perkinsozoa, a recently established phylum considered close to the ancestor of ciliates, dinoflagellates, and apicomplexans, and a key taxon for understanding unique adaptations

Sandeep J. Joseph; José A. Fernández-Robledo; Malcolm J. Gardner; Najib M El-Sayed; Chih-Horng Kuo; Eric J Schott; Haiming Wang; Jessica C Kissinger; Gerardo R Vasta

2010-01-01

302

The phylogenetic position of Rhopalura ophiocomae (Orthonectida) based on 18S ribosomal DNA sequence analysis.  

PubMed

The Orthonectida is a small, poorly known phylum of parasites of marine invertebrates. Their phylogenetic placement is obscure; they have been considered to be multicellular protozoans, primitive animals at a "mesozoan" grade of organization, or secondarily simplified flatworm-like organisms. The best known species in the phylum, Rhopalura ophiocomae, was collected on San Juan Island, Wash. and a complete 18S rDNA sequence was obtained. Using the models of minimum evolution and parsimony, phylogenetic analyses were undertaken and the results lend support to the following hypotheses about orthonectids: (1) orthonectids are more closely aligned with triploblastic metazoan taxa than with the protist or diploblastic metazoan taxa considered in this analysis; (2) orthonectids are not derived members of the phylum Platyhelminthes; and (3) orthonectids and rhombozoans are not each other's closest relatives, thus casting further doubt on the validity of the phylum Mesozoa previously used to encompass both groups. PMID:8896370

Hanelt, B; Van Schyndel, D; Adema, C M; Lewis, L A; Loker, E S

1996-11-01

303

The apicoplast: a red alga in human parasites.  

PubMed

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

Striepen, Boris

2011-01-01

304

In silico analysis of the cyclophilin repertoire of apicomplexan parasites  

PubMed Central

Background Cyclophilins (Cyps) are peptidyl cis/trans isomerases implicated in diverse processes such as protein folding, signal transduction, and RNA processing. They are also candidate drug targets, in particular for the immunosuppressant cyclosporine A. In addition, cyclosporine is known to exhibit anti-parasitic effects on a wide range of organisms including several apicomplexa. In order to obtain new non-immunosuppressive drugs targeting apicomplexan cyclophilins, a profound knowledge of the cyclophilin repertoire of this phylum would be necessary. Results BLAST and maximum likelihood analyses identified 16 different cyclophilin subfamilies within the genomes of Cryptosporidium hominis, Toxoplasma gondii, Plasmodium falciparum, Theileria annulata, Theileria parva, and Babesia bovis. In addition to good statistical support from the phylogenetic analysis, these subfamilies are also confirmed by comparison of cyclophilin domain architecture. Within an individual genome, the number of different Cyp genes that could be deduced varies between 7–9 for Cryptosporidia and 14 for T. gondii. Many of the putative apicomplexan cyclophilins are predicted to be nuclear proteins, most of them presumably involved in RNA processing. Conclusion The genomes of apicomplexa harbor a cyclophilin repertoire that is at least as complex as that of most fungi. The identification of Cyp subfamilies that are specific for lower eukaryotes, apicomplexa, or even the genus Plasmodium is of particular interest since these subfamilies are not present in host cells and might therefore represent attractive drug targets. PMID:19555495

Krucken, Jurgen; Greif, Gisela; von Samson-Himmelstjerna, Georg

2009-01-01

305

Elongator Protein 3 (Elp3) Lysine Acetyltransferase Is a Tail-anchored Mitochondrial Protein in Toxoplasma gondii *  

PubMed Central

Lysine acetylation has recently emerged as an important, widespread post-translational modification occurring on proteins that reside in multiple cellular compartments, including the mitochondria. However, no lysine acetyltransferase (KAT) has been definitively localized to this organelle to date. Here we describe the identification of an unusual homologue of Elp3 in early-branching protozoa in the phylum Apicomplexa. Elp3 is the catalytic subunit of the well-conserved transcription Elongator complex; however, Apicomplexa lack all other Elongator subunits, suggesting that the Elp3 in these organisms plays a role independent of transcription. Surprisingly, Elp3 in the parasites of this phylum, including Toxoplasma gondii (TgElp3), possesses a unique C-terminal transmembrane domain (TMD) that localizes the protein to the mitochondrion. As TgElp3 is devoid of known mitochondrial targeting signals, we used selective permeabilization studies to reveal that this KAT is oriented with its catalytic components facing the cytosol and its C-terminal TMD inserted into the outer mitochondrial membrane, consistent with a tail-anchored membrane protein. Elp3 trafficking to mitochondria is not exclusive to Toxoplasma as we also present evidence that a form of Elp3 localizes to these organelles in mammalian cells, supporting the idea that Elp3 performs novel functions across eukaryotes that are independent of transcriptional elongation. Importantly, we also present genetic studies that suggest TgElp3 is essential in Toxoplasma and must be positioned at the mitochondrial surface for parasite viability. PMID:23878194

Stilger, Krista L.; Sullivan, William J.

2013-01-01

306

Sirtuins of parasitic protozoa: In search of function(s)  

PubMed Central

The SIR2 family of NAD+-dependent protein deacetylases, collectively called sirtuins, has been of central interest due to their proposed roles in life-span regulation and ageing. Sirtuins are one group of environment sensors of a cell interpreting external information and orchestrating internal responses at the sub-cellular level, through participation in gene regulation mechanisms. Remarkably conserved across all kingdoms of life SIR2 proteins in several protozoan parasites appear to have both conserved and intriguing unique functions. This review summarises our current knowledge of the members of the sirtuin families in Apicomplexa, including Plasmodium, and other protozoan parasites such as Trypanosoma and Leishmania. The wide diversity of processes regulated by SIR2 proteins makes them targets worthy of exploitation in anti-parasitic therapies. PMID:22906508

Religa, Agnieszka A.; Waters, Andrew P.

2012-01-01

307

Mineralization of nitrogen by protozoan activity in soil  

Microsoft Academic Search

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

P. J. Kuikman

1990-01-01

308

IMP Dehydrogenase from the Protozoan Parasite Toxoplasma gondii  

PubMed Central

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

Sullivan, William J.; Dixon, Stacy E.; Li, Catherine; Striepen, Boris; Queener, Sherry F.

2005-01-01

309

Studies of the Ossicles from the Ciliate Protozoan Spirostomum ambiguum  

NASA Astrophysics Data System (ADS)

Spirostomum ambiguum is able to concentrate intracellular deposits of calcium phosphate. This mineralization process is dependent on the age of the culture and can be stimulated by an applied piezoelectric potential. Crystalline deposits induced to form in laboratory cultures were analysed both in situ and after isolation from the cells, using transmission and scanning electron microscopies, energy dispersive microanalysis, and optical spectrophotometry. The ratio of Ca:P (1.57±0.01) fits with the expected value for hydroxyapatite.

Takagui, Regina; Silveira, Marina

1999-09-01

310

Dientamoeba fragilis in Gaza Strip: a Neglected Protozoan Parasite  

PubMed Central

Background The aim of this study was to detect Dientamoeba fragilis by iron haematoxylin stain, as well as its prevalence, and association between D. fragilis infection and diarrhoea among patients attending Al-Nuseirate Refugee Camp Clinic, Gaza Strip. Methods A cross-sectional study was conducted among 319 children and adults with age ranges from (1 to 75) years old, attending Al-Nussirat Clinic, and who were complaining from clinical symptoms, like diarrhoea and abdominal pain. Results 28 individuals were infected with D. fragilis with a prevalence of 8.8%. The detection of 28 cases infected with D. fragilis was proved using iron haematoxylin stain, but no case was detected by direct smear or formal-ether sedimentation technique. The most frequent symptoms were abdominal pain (96.4%) and diarrhoea (71.4%) in patients with diantamoebiasis and this was statistically significant (P= 0.03). Co-infection between D. fragilis and Entamoeba histolytica/dispar was 50% and between D. fragilis and Giardia lamblia was 7.1%. Conclusion D. fragilis was present in the patients stool samples and was detected and proved using iron haematoxylin stain. PMID:23914238

Al-Hindi, Adnan I.; Shammala, Basma M. Abu

2013-01-01

311

Helminth and protozoan parasites in dogs and cats in Belgium.  

PubMed

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

Vanparijs, O; Hermans, L; van der Flaes, L

1991-01-01

312

IMMUNOLOGICAL TECHNIQUES FOR DETECTING PROTOZOAN AGENTS OF WATERBORNE DISEASES  

EPA Science Inventory

Research is undertaken to develop practical and rapid methods for isolation, identification, and quantification of waterborne pathogens. Research is also conducted to determine human exposure to these pathogens. Of immediate concern is Cryptosporidium for which such standardize...

313

Localization of mechanoreceptors in the protozoan, Stentor coeruleus.  

PubMed

Mechanoreceptor channels were localized by using the ligands, tubocurarine (TC), decamethonium (Deca), and gallamine (Gall), which have been shown to bind specifically to these channels. The binding of radioactively labeled TC (TC*) was found to be directly proportional to the cell surface area suggesting that the channels are uniformly distributed over the cell surface. Intracellular TC and Gall injections did not depress mechanical stimulus sensitivity though these drugs did depress sensitivity when applied extracellularly at the same concentrations; therefore, the ligand binding sites are on or near the external surface of the cell. Autoradiographs revealed that radioactively labeled Deca (Deca*) bound to the pigmented stripes but not to the ciliary stripes or membranellar band. Further, Stentor induced to shed their membranellar band through exposure to 8% urea were more sensitive to mechanical stimuli than were controls; therefore, the membranellar cilia do not appear to contain mechanoreceptor channels. Collectively, these data indicate that the mechanoreceptor channels are located in the somatic surface covering the pigmented stripes. The density of mechanoreceptor channels in the plasma membrane covering the somatic surface is tentatively estimated to be between 5500 and 14,500 microns-2 based on the density of TC* binding, the apparent number of TC molecules binding per mechanoreceptor channel, and data suggesting that only one fifth to one fourth of the bound TC* is bound to structures in the plasma membrane. PMID:2746550

Wood, D C

1989-01-01

314

Chemosensory Responses ofaProtozoan Areiedby Modified byAntitubulins  

Microsoft Academic Search

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

M. LEVANDOWSKY; D. C. R. HAUSER; M. GLASSGOLD

1975-01-01

315

Experimental infections with the protozoan parasite Histomonas meleagridis: a review.  

PubMed

In recent years, a number of studies about Histomonas meleagridis, and more specifically about experiments in vivo involving H. meleagridis to investigate the pathogenicity and efficacy of drugs or vaccines, have been published. Together with older publications, a considerable amount of information about experimental infections with H. meleagridis exist, which is helpful for planning future animal studies and can reduce the number of birds used in such studies toward better animal welfare. One hundred sixty-seven publications describing experimental infections with H. meleagridis were published in scientific journals between 1920 and 2012. One hundred forty-two of these publications describe infections of turkeys (Meleagris gallopavo) and 52 infections of chickens (Gallus gallus). In 18 studies, experiments involving other species were done. The most popular routes of infection were the intracloacal application of histomonal trophozoites from culture material, from lesions or from feces of infected birds, or using larvae of the cecal worm Heterakis gallinarum (83 studies) and the oral application of eggs or other stages of the cecal worm containing histomonal stages (83 studies). During the last 10 years, intracloacal application of trophozoites has become the most popular way to experimentally infect birds with H. meleagridis due to its high reproducibility and reliability. In most studies, infection doses of several 10,000 or 100,000 histomonal trophozoites were used for infection, and the resulting mortality in turkeys was more than 70 %. First mortality can occur as early as 6 days p.i.; peak mortality usually is 13-15 days p.i. Lower infection doses may delay mortality about 2 days. In chickens infected by the intracloacal route, mortality and clinical signs are rare, but infection rates are similar. Cecal lesions can be observed from 3 to 4 days p.i., lesions up to 3 weeks p.i.; liver lesions may be lacking completely or be present only in a small number of birds. In most studies infecting birds with Heterakis eggs containing histomonal stages, several 100 to 1,000 Heterakis eggs were used. However, lower doses might be sufficient, as infection with as few as 58 eggs per bird caused a mortality up to 90 % in turkeys. Clinical symptoms start 9 days p.i., and first mortality occurs after 12 days, while most of the infected birds die between 19 and 21 days p.i. The infectivity of Heterakis eggs containing histomonal stages for chickens is similar as for turkeys, but mortality and clinical signs are rare. Further infection was done by oral application of histomonal trophozoites either grown in culture or using lesions or feces of infected birds (26 studies). These yielded very mixed results, with infection rates between 0 and more than 80 % in turkeys and chickens. After successful oral infection of turkeys, mortality occurs at roughly the same time as after intracloacal infection. Further 18 studies employed seeder birds to infect in-contact birds. Other means of infection were exposure to contaminated soil or litter (22 studies), feeding contaminated earthworms (7 studies), intracecal inoculation (4 studies), or parenteral injection (4 studies). Main methods to assess the course of the infection were mortality, observation of clinical signs and pathological lesions, monitoring of the weight of the infected birds, and detection of the parasite by various methods. PMID:23160894

Hauck, Rüdiger; Hafez, Hafez M

2013-01-01

316

GTPases in Protozoan Parasites: Tools for Cell Biology and Chemotherapy  

Microsoft Academic Search

Small G proteins belong to a superfamily of GTPases related to the protooncogene ras, and function as master control elements for a range of cellular functions. This ability is related to their low rate of substrate turnover; GTPases catalyse the conversion of GTP to GDP, but with a rate in the order of one substrate per second, orders of magnitude

M. C. Field; B. R. S. Ali; H. Field

1999-01-01

317

Protozoan grazing of bacteria in soil—impact and importance  

Microsoft Academic Search

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

Marianne Clarholm

1981-01-01

318

[Common tropical infections with protozoans, worms and ectoparasites].  

PubMed

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

Schliemann, S

2014-10-01

319

Plasmodiophorids: The Challenge to Understand Soil-Borne, Obligate Biotrophs with a Multiphasic Life Cycle  

Microsoft Academic Search

\\u000a Plasmodiophorids are an enigmatic group of obligate biotrophic pathogens of higher plants. Together with their sister group\\u000a phagomyxids, which infect stramenopiles, they form the monophyletic eukaryote clade phytomyxids. They have long been treated\\u000a as a basal group of fungi, but recent molecular phylogenies point to a close affiliation with the protozoan phylum Cercozoa.\\u000a The soil-borne and plant-associated nature of plasmodiophorids

Sigrid Neuhauser; Simon Bulman; Martin Kirchmair

320

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

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

Telford, S R; Wozniak, E J; Butler, J F

2001-08-01

321

Kingdoms Protozoa and Chromista and the eozoan root of the eukaryotic tree.  

PubMed

I discuss eukaryotic deep phylogeny and reclassify the basal eukaryotic kingdom Protozoa and derived kingdom Chromista in the light of multigene trees. I transfer the formerly protozoan Heliozoa and infrakingdoms Alveolata and Rhizaria into Chromista, which is sister to kingdom Plantae and arguably originated by synergistic double internal enslavement of green algal and red algal cells. I establish new subkingdoms (Harosa; Hacrobia) for the expanded Chromista. The protozoan phylum Euglenozoa differs immensely from other eukaryotes in its nuclear genome organization (trans-spliced multicistronic transcripts), mitochondrial DNA organization, cytochrome c-type biogenesis, cell structure and arguably primitive mitochondrial protein-import and nuclear DNA prereplication machineries. The bacteria-like absence of mitochondrial outer-membrane channel Tom40 and DNA replication origin-recognition complexes from trypanosomatid Euglenozoa roots the eukaryotic tree between Euglenozoa and all other eukaryotes (neokaryotes), or within Euglenozoa. Given their unique properties, I segregate Euglenozoa from infrakingdom Excavata (now comprising only phyla Percolozoa, Loukozoa, Metamonada), grouping infrakingdoms Euglenozoa and Excavata as the ancestral protozoan subkingdom Eozoa. I place phylum Apusozoa within the derived protozoan subkingdom Sarcomastigota. Clarifying early eukaryote evolution requires intensive study of properties distinguishing Euglenozoa from neokaryotes and Eozoa from neozoa (eukaryotes except Eozoa; ancestrally defined by haem lyase). PMID:20031978

Cavalier-Smith, Thomas

2010-06-23

322

Kingdoms Protozoa and Chromista and the eozoan root of the eukaryotic tree  

PubMed Central

I discuss eukaryotic deep phylogeny and reclassify the basal eukaryotic kingdom Protozoa and derived kingdom Chromista in the light of multigene trees. I transfer the formerly protozoan Heliozoa and infrakingdoms Alveolata and Rhizaria into Chromista, which is sister to kingdom Plantae and arguably originated by synergistic double internal enslavement of green algal and red algal cells. I establish new subkingdoms (Harosa; Hacrobia) for the expanded Chromista. The protozoan phylum Euglenozoa differs immensely from other eukaryotes in its nuclear genome organization (trans-spliced multicistronic transcripts), mitochondrial DNA organization, cytochrome c-type biogenesis, cell structure and arguably primitive mitochondrial protein-import and nuclear DNA prereplication machineries. The bacteria-like absence of mitochondrial outer-membrane channel Tom40 and DNA replication origin-recognition complexes from trypanosomatid Euglenozoa roots the eukaryotic tree between Euglenozoa and all other eukaryotes (neokaryotes), or within Euglenozoa. Given their unique properties, I segregate Euglenozoa from infrakingdom Excavata (now comprising only phyla Percolozoa, Loukozoa, Metamonada), grouping infrakingdoms Euglenozoa and Excavata as the ancestral protozoan subkingdom Eozoa. I place phylum Apusozoa within the derived protozoan subkingdom Sarcomastigota. Clarifying early eukaryote evolution requires intensive study of properties distinguishing Euglenozoa from neokaryotes and Eozoa from neozoa (eukaryotes except Eozoa; ancestrally defined by haem lyase). PMID:20031978

Cavalier-Smith, Thomas

2010-01-01

323

Ultrastructural analyses support different morphological lineages in the phylum Placozoa Grell, 1971.  

PubMed

The morphology and ultrastructure of 10 clonal placozoan lineages were studied. We scored several morphological characters at a cellular and intracellular level and identified a number of morphological differences among clones. Some differences appear clone specific and allow recognizing five distinct lineages based on morphological criteria only. These data will be crucial for a yet to be established placozoan systematics. Furthermore, we here describe three new diagnostic morphological characters for Placozoa: a new structure in the upper epithelium, called "concave disc," two distinct subpopulations of fiber cells, and especially small cells in the body margin. Besides the fiber cells appear to be arranged in several layers forming a complex, three-dimensional net not previously described. We also describe the marginal cells as the formerly suggested potential stem-cell type. The basic morphology is revised. PMID:21246596

Guidi, Loretta; Eitel, Michael; Cesarini, Erica; Schierwater, Bernd; Balsamo, Maria

2011-03-01

324

Phylum and Class-Specific PCR Primers for General Microbial Community Analysis  

Microsoft Academic Search

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

Christopher B. Blackwood; Adam Oaks; Jeffrey S. Buyer

2005-01-01

325

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

E-print Network

of Sciences, St. Petersburg, Russia and 4National Systematics Laboratory of NOAA Fisheries Service, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA Email: Nathaniel M Evans - evansnat@ku.edu; Alberto Lindner...

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

2009-07-15

326

Depth Distribution for the Order Cydippid (Phylum Ctenophora, Class Tentaculata) in the Monterey Submarine Canyon  

Microsoft Academic Search

This paper will discuss depth distribution analysis of cydippids in the Monterey Bay Submarine Canyon. Cydippids in the Monterey Canyon have been sighted at many different depths and areas. Since 1989, ten different cydippid species, including two new cydippids this year, were recorded on video using a remotely operated vehicle in ten sites within the Monterey Canyon. Because most of

Laura Dippold; Judith Connor; Nancy Jacobsen

327

Diversity of Freshwater Thioploca Species and Their Specific Association with Filamentous Bacteria of the Phylum Chloroflexi  

Microsoft Academic Search

Phylogenetic diversity among filamentous sulfur-oxidizing bacteria of the genus Thioploca inhabiting freshwater\\/brackish environments was analyzed in detail. The 16S rRNA gene sequence of Thioploca found in a freshwater lake in Japan, Lake Okotanpe, was identical to that of Thioploca from Lake Ogawara, a brackish lake. The samples of the two lakes could be differentiated by the sequences of their 23S

Fumiko Nemoto; Hisaya Kojima; Manabu Fukui

328

Phylogeny of Arenig to Caradoc crinoids (Phylum Echinodermata) and suprageneric classification of the Crinoidea  

E-print Network

Oval Mall, The Ohio State University, Columbus, OH 43210, ausich@mps.ohio-state.edu Abstract.—Stepwise, parsimony-based character analysis of Arenig to Caradoc crinoids (Ordovician) indi- cates that Early and middle Ordovician crinoids represent a... radiation largely confined to the Ordovician. Only a few middle Paleozoic families are considered to have roots among these Early and middle Ordovician genera. Also, most genera are reinterpreted as a part of larger Ordovician clades rather than being...

Ausich, W. I.

1998-06-01

329

Spliced leader RNA-mediated trans-splicing in phylum Rotifera.  

PubMed

In kinetoplastids, Euglena, and four metazoan phyla, trans-splicing has been described as a mechanism for the generation of mature messenger RNAs (mRNAs): 5'-ends of precursor mRNAs are replaced by a short spliced leader (SL) exon from a small SL RNA. Although the full phylogenetic range is unknown, trans-splicing has not been found in vertebrates, insects, plants, or yeast. In animal groups where it does occur, i.e., nematodes, cnidarians, platyhelminths, and primitive chordates, SL RNAs do not show sequence relatedness across phyla. The apparently sporadic phylogenetic distribution and the lack of SL RNA homology have led to opposing hypotheses on its evolution, involving either an ancient origin followed by loss in multiple lineages or independent acquisition in several taxa. Here we present evidence for the occurrence of trans-splicing in bdelloid rotifers (Bdelloidea, Rotifera). A common 23-nt sequence, representing the SL exon-diagnostic of SL RNA-mediated trans-splicing-was found at the 5'-end of at least 50%-65% of mRNAs from Adineta ricciae and Philodina sp. The trans-splicing pattern in bdelloid rotifers can be unusually complex, as observed in transcripts from a heat shock protein gene, hsp82-1, where the SL exon was spliced to three alternative positions. Bdelloid rotifer SL RNAs were found to be 105 or 106 nt long and comprised the SL sequence, a conserved splice donor site and an intron containing a putative spliceosome-binding motif. Intriguingly, some similarity of rotifer SL RNA sequence and predicted secondary structure was seen to that of the predominant SL1 RNA of nematodes, although it is unlikely that this demonstrates homology. In addition, sequence corresponding to the rotifer SL exon was found at the 5'-end of a number of full-length complementary DNA (cDNA) clones in a rice (Oryza sativa) database. None of these cDNAs gave a close match with homologous plant genes, suggesting that a small but significant portion of the rice expressed sequence tag database represents sequences derived from rotifers. In summary, the description of SL-mediated trans-splicing in Rotifera extends its representation to at least five metazoan phyla, making it increasingly probable that this is a phylogenetically widespread and therefore ancient phenomenon. PMID:15788744

Pouchkina-Stantcheva, Natalia N; Tunnacliffe, Alan

2005-06-01

330

Evaluating the use of DNA Sequences for Species Identification in Medusozoans (Phylum Cnidaria)  

E-print Network

identif ications t h r o u g h D N A b a r c o d e s . Proceedings of the Royal Society, 2 7 0 , 313¬ 3 2 1 . Hol l ingsworth , Peter et al. (2009) A D N A b a r c o d e for land plants . Proceedings of the National Academy of Sciences of the United... l o g e o g r a p h y in the c o s m o p o l i t a n m a r i n e m o o n jelly, Aurelia sp. BMC Evolutionary Biology, 2. Singleton, David R.; Michel le A Furlong; Stephen L. R a t h b u n ; and W i l l i a m B. W h i t m a n (2001) Quantitat ive...

Richardson, Rhea

2012-04-01

331

Differential gene expression between functionally specialized polyps of the colonial hydrozoan Hydractinia symbiolongicarpus (Phylum Cnidaria)  

E-print Network

, and ortho began with mapping 12 non-normalized libraries to the final transcriptome a polyp-specific DEs were compared to the annotated transcriptome.Approximately 54% of the transcriptome (35,636 transcripts) was annotated using Blast2GO, CEGMA, orthoMCL... by transcript size, removing assembled MCL were used to annotate the transcriptome. Differential expression ssembly with Bowtie2. DE was then assessed with DESeq and edgeR and at least one database in our annotation pipeline (Figures 2 and 3). These include 416...

Sanders, Steven M.; Shcheglovitova, Mariya; Cartwright, Paulyn

2014-01-01

332

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

E-print Network

: A review of phylogenetic patterns and diversity 300 years after Linnaeus* MARYMEGAN DALY1, MERCER R. BRUGLER2, PAULYN CARTWRIGHT3, ALLEN G. COLLINS4, MICHAEL N. DAWSON5, DAPHNE G. FAUTIN3, SCOTT C. FRANCE2, CATHERINE S. MCFADDEN6, DENNIS M...

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

333

Phylum- and Class-Specific PCR Primers for General Microbial Community Analysis  

PubMed Central

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 the present study was to develop several primer sets targeting commonly occurring and important groups. Primers specific for the 16S ribosomal sequences of Alphaproteobacteria, Betaproteobacteria, Bacilli, Actinobacteria, and Planctomycetes and for parts of both the 18S ribosomal sequence and the internal transcribed spacer region of Basidiomycota were examined. Primers were tested by comparison to sequences in the ARB 2003 database, and chosen primers were further tested by cloning and sequencing from soil community DNA. Eighty-five to 100% of the sequences obtained from clone libraries were found to be placed with the groups intended as targets, demonstrating the specificity of the primers under field conditions. It will be important to reevaluate primers over time because of the continual growth of sequence databases and revision of microbial taxonomy. PMID:16204538

Blackwood, Christopher B.; Oaks, Adam; Buyer, Jeffrey S.

2005-01-01

334

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

E-print Network

EU272635 MHNG INVE35757 Hydrozoa, Filifera Turritopsis dohrnii EU272596 EU272638 MHNG INVE29753 Hydrozoa, Leptothecata Abietinaria filicula EU272540 EU272600 MHNG INVE29947 Hydrozoa, Leptothecata Aglaophenia tubiformis EU272543 EU272601 MHNG INVE29967...

Evans, Nathaniel Michael; Linder, Alberto; Raikova, Ekaterina V.; Collins, Allen G.; Cartwright, Paulyn

2008-05-09

335

Functional diversification of ROK-family transcriptional regulators of sugar catabolism in the Thermotogae phylum  

PubMed Central

Large and functionally heterogeneous families of transcription factors have complex evolutionary histories. What shapes specificities toward effectors and DNA sites in paralogous regulators is a fundamental question in biology. Bacteria from the deep-branching lineage Thermotogae possess multiple paralogs of the repressor, open reading frame, kinase (ROK) family regulators that are characterized by carbohydrate-sensing domains shared with sugar kinases. We applied an integrated genomic approach to study functions and specificities of regulators from this family. A comparative analysis of 11 Thermotogae genomes revealed novel mechanisms of transcriptional regulation of the sugar utilization networks, DNA-binding motifs and specific functions. Reconstructed regulons for seven groups of ROK regulators were validated by DNA-binding assays using purified recombinant proteins from the model bacterium Thermotoga maritima. All tested regulators demonstrated specific binding to their predicted cognate DNA sites, and this binding was inhibited by specific effectors, mono- or disaccharides from their respective sugar catabolic pathways. By comparing ligand-binding domains of regulators with structurally characterized kinases from the ROK family, we elucidated signature amino acid residues determining sugar-ligand regulator specificity. Observed correlations between signature residues and the sugar-ligand specificities provide the framework for structure functional classification of the entire ROK family. PMID:23209028

Kazanov, Marat D.; Li, Xiaoqing; Gelfand, Mikhail S.; Osterman, Andrei L.; Rodionov, Dmitry A.

2013-01-01

336

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

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

Slapeta, Jan; Linares, Marjorie C.

2013-01-01

337

Molecular survey of Apicomplexa in Podarcis wall lizards detects Hepatozoon, Sarcocystis, and Eimeria species.  

PubMed

The occurrence of apicomplexan parasites in Podarcis sp. wall lizards from the Iberian Peninsula and Balearic islands was studied by amplification and sequencing of the 18S rRNA gene. Species from 3 genera, Hepatozoon , Sarcocystis , and Eimeria , were found. The phylogenetic analysis of the 18S rRNA gene provides unexpected insights into the evolutionary history of these parasites. All Hepatozoon spp. specimens were recovered as part of a clade already identified in lizards from North Africa. The Sarcocystis species, detected in Podarcis lilfordi from Cabrera Island in the Balearic Islands, appears related to Sarcocystis gallotiae , known only from endemic Gallotia sp. lizards from the Canary Islands. Based on the lack of snake predators on this island, this parasite presumably presents an atypical transmission cycle that uses the same host species as both intermediate and final host through cannibalism, like S. gallotiae . Eimeria sp. is reported for the first time from Podarcis spp. lizards. This study shows the power of detecting multiple different apicomplexan parasites through screening of tail tissue samples and blood drops that are often collected in reptiles for other purposes. PMID:22746392

Harris, D James; Maia, João P M C; Perera, Ana

2012-06-01

338

Isospora troglodytes n. sp. (Apicomplexa: Eimeriidae), a new coccidian species from wrens of Costa Rica.  

PubMed

Nineteen (91%) of 21 rufous-and-white wrens (Thryothorus rufalbus) and five (71%) of seven plain wrens (Cantorchilus modestus) sampled from Costa Rica were positive for a new species of Isospora. Oocysts have a thin, smooth, double, colorless wall and measure 20.1 ± 1.4 × 23.4 ± 1.5 ?m (18-24 × 20-26 ?m) with an average length-width ratio of 1.2 ?m. Sporocysts are ovoid, measure 9.5 ± 0.9 × 15.5 ± 1.1 ?m (7-12 × 12-18 ?m) with an average length-width ratio of 1.6 ?m. A nipple-like steida body continuous with the sporocyst wall and a prominent oval-shaped substeida body are present. In addition to the four sporozoites, a single compact sporocyst residuum was present in each sporocyst. This is the first description of an Isospora species from the family Troglodytidae and the first report of Isospora from the rufous-and-white wren and plain wren. PMID:22006192

Keeler, Shamus P; Yabsley, Michael J; Fox, Julie M; McGraw, Sabrina N; Hernandez, Sonia M

2012-05-01

339

A novel Isospora species (Apicomplexa: Eimeriidae) from warblers (Passeriformes: Parulidae) of Costa Rica.  

PubMed

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

Keeler, Shamus P; Yabsley, Michael J; Adams, Henry C; Hernandez, Sonia M

2014-06-01

340

Three new species of Coccidia (Apicomplexa: Eimeriidae) from Skinks, Lipinia spp. (Sauria: Scincidae), from Oceania  

USGS Publications Warehouse

Between September 1991 and March 1993, 25 moth skinks (Lipinia noctua) were collected from various localities on the Cook Islands, Fiji, Papua New Guinea (PNG), and Vanuatu and examined for coccidians. In addition, a single Roux's lipinia skink (Lipinia rouxi) was collected from PNG and examined for coccidia. Sixteen (64%) L. noctua were found to harbor 2 new eimerians, and L. rouxi harbored another new Eimeria sp. Oocysts of Eimeria lipinia n. sp. from 9 (36%) L. noctua from the Cook Islands, Fiji, and PNG were subspherical with a bilayered wall and measured (L × W) 18.6 × 16.9 ?m, with a L/W ratio of 1.1. Both micropyle and oocyst residuum were absent, but a polar granule was present. Oocysts of Eimeria melanesia n. sp. from 6 (24%) L. noctua from Fiji and Vanuatu and a single L. rouxi from PNG were subspherical to ellipsoidal with a bilayered wall and measured 19.8 × 17.5 ?m, and L/W was 1.1. Both micropyle and oocyst residuum were absent, but a single or fragmented polar granule was present. Oocysts of Eimeria lessoni n. sp. from 1 (4%) L. noctua from PNG were cylindroidal with a bilayered wall and measured 28.1 × 15.7 ?m, and L/W was 1.8. Both micropyle and oocyst residuum were absent, but a single polar granule was present. These represent the third report of Eimeria spp. reported from any host on PNG and the only coccidians, to our knowledge, ever described from L. noctua and L. rouxi and from the Cook Islands and Vanuatu.

McAllister, Chris T.; Duszynski, Donald W.; Austin, Christopher C.; Fisher, Robert N.

2013-01-01

341

A new Eimeria species (Apicomplexa: Eimeriidae) infecting Onychomys species (Rodentia: Muridae) in New Mexico and Arizona.  

PubMed

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

Hnida, J A; Wilson, W D; Duszynski, D W

1998-12-01

342

Ultrastructural development of the sarcocyst of Sarcocystis rauschorum (Apicomplexa: Sarcocystidae) in the varying lemming Dicrostonyx richardsoni.  

PubMed

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

Friesen, D L; Cawthorn, R J; Speer, C A; Brooks, R J

1989-06-01

343

Caryospora uptoni n. sp. (Apicomplexa: Eimeriidae) from red-tailed hawks (Buteo jamaicensis borealis).  

PubMed

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

Lindsay, D S; Blagburn, B L

1986-10-01

344

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...

345

Species of Eimeria (Apicomplexa: Eimeriidae) from bats (Chiroptera: Vespertilionidae) in central Wyoming.  

PubMed

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

Seville, Robert S; Gruver, Jeffrey

2004-04-01

346

A new species of Sarcocystis (Apicomplexa: Sarcocystidae) from the black bear (Ursus americanus).  

PubMed

Infection with Sarcocystis species is common in herbivores but is rare in bears. Histological sections of 374 black bears (Ursus americanus) from Pennsylvania were examined for sarcocysts. In total, 3 sarcocysts were found in 3 bears, with 1 sarcocyst per section. Sarcocysts from 2 bears were considered a new species, Sarcocystis ursusi. Sarcocysts of S. ursusi n. sp. were microscopic and contained only bradyzoites. By light microscopy, the sarcocyst wall was thin (< 0.5 microm thick) and had minute serrations. Ultrastructurally, the serrations on the sarcocyst wall consisted of villar protrusions (Vp) that were mostly 0.5 microm long. The Vp had bundles of electron-dense microtubules that were as wide as long; these microtubules extended deep into the ground substance layer, a feature that distinguished this species from unnamed sarcocysts from black bear. Bradyzoites were 4.8-6.0 microm long. The sarcocyst from the third bear was structurally different from S. ursusi; its sarcocyst wall was approximately 2 microm thick and had finger-like villi on the cyst wall giving the sarcocyst wall a striated appearance. PMID:18564883

Dubey, J P; Humphreys, G; Fritz, D

2008-04-01

347

Three new Hepatozoon species (Apicomplexa: Hepatozoidae) infecting the Florida kingsnake, Lampropeltis getula floridana.  

PubMed

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

Telford, Sam R

2010-02-01

348

Coccidian parasites (Apicomplexa: Eimeriidae) of the endemic Florida snake Tantilla relicta Telford (Serpentes: Colubridae)  

Microsoft Academic Search

The endemic Florida snake Tantilla relicta Telford is parasitised by six species of coccidia. Caryospora tantillae n. sp. has nearly spherical oöcysts, 19.6 × 18.9 µm (16–22 × 16–21), with no polar body, and an oöcyst length\\/width ratio (shape index, SI) of 1.04 (1.00–1.11). Ovoidal sporocysts are 15.1 × 11.6 µm (12–17 × 10–13), with an SI of 1.30 (1.1–1.6),

Sam R. Telford Jr

1997-01-01

349

New species of Eimeria (Apicomplexa: Eimeriidae) from the domesticated goat Capra hircus in New Zealand  

Microsoft Academic Search

Three new species of the genus Eimeria Schneider, 1875 are described from the faeces of domesticated goats in New Zealand. Oöcysts of E. capralis n. sp. are ellipsoidal, 29.2 × 19.7 (25–34 × 17–24) ?m, with a distinct micropylar cap. The sporocysts are broadly ovoid,\\u000a the Stieda body is present and the sporocyst residuum consists of many scattered granules. Sporozoites

A. K. Soe; W. E. Pomroy

1992-01-01

350

Occurrence of Leucocytozoon and Haemoproteus (Apicomplexa, Haemosporina) in Falconiformes and Strigiformes of Italy.  

PubMed

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

Sacchi, L; Prigioni, C

1984-01-01

351

Coccidia (Apicomplexa: Eimeriidae) from the big bend slider, Trachemys gaigeae (Testudines: Emydidae), in New Mexico.  

PubMed

Twenty-nine Big Bend sliders Trachemys gaigeae (Hartweg, 1934) were collected from Socorro County, New Mexico, and their feces examined for coccidial parasites. Three (10%) of the turtles were found to be infected with at least 1 coccidian. Seven Eimeria spp. (E. chrysemydis, E. graptemydos, E. marginata, E. pseudemydis, E. pseudogeographica, E. stylosa, and E. trachemydis) were harbored by T. gaigeae. All represent new host and distributional records for these previously described coccidians. In addition, a single sympatric western painted turtle (Chrysemys picta bellii) harbored E. chrysemydis, E. graptemydos, and E. trachemydis. The latter coccidian is reported for the first time from C. picta bellii. PMID:7472884

McAllister, C T; Stuart, J N; Upton, S J

1995-10-01

352

New host and geographic records for coccidia (Apicomplexa: Eimeriidae) from North American turtles.  

PubMed

Two-hundred-fifty-three turtles, representing 26 species within 5 families (Chelydridae, Emydidae, Kinosternidae, Testudinidae, Trionychidae) were examined for coccidia. Of these, 127 (50%) were found to harbor 1 or more of 28 species of eimerians, or isosporan, or both. One-hundred-thirteen (89%) of the infected turtles were aquatic species, whereas only 14 (11%) of the infected turtles were terrestrial species. Two-fold more aquatic turtles were infected with coccidia (113 of 200, 57%) compared to only 26% (14 of 53) of the terrestrial species. This report documents 14 new host and 8 new geographic records for eimerians from turtles in Arkansas and Texas. PMID:7799150

McAllister, C T; Upton, S J; Trauth, S E

1994-12-01

353

Coccidian parasites (Apicomplexa: Eimeriidae) of Graptemys caglei and Graptemys versa (Testudines: Emydidae) from Texas.  

PubMed

Nineteen map turtles, Graptemys caglei and Graptemys versa were collected from the Guadalupe and Colorado River watersheds of south-central Texas and examined for coccidial parasites. Thirteen of the 19 turtles (68%), including 11 of 16 (69%) G. caglei and 2 of 3 (67%) G. versa, were infected with at least 1 coccidian. Five Eimeria spp. (E. chrysemydis, E. graptemydos, E. lutotestudinis, E. pseudogeographica, and E. trachemydis) were harbored by G. caglei, and 2 eimerians (E. graptemydos and E. mitraria) infected G. versa. This represents new host records for these previously described coccidians and is the first time parasites have been documented in turtles of both species. PMID:2040965

McAllister, C T; Upton, S J; Killebrew, F C

1991-06-01

354

Complete mitochondrial genome sequences from five Eimeria species (Apicomplexa; Coccidia; Eimeriidae) infecting domestic turkeys  

PubMed Central

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

2014-01-01

355

A new eimeriid (Apicomplexa) species from endangered Attwater's prairie chickens (Tympanuchus cupido attwateri) in Texas.  

PubMed

The Attwater's prairie chicken (APC; Tympanuchus cupido attwateri Bendire, 1894) has been a federally listed endangered species since 1967. Several captive propagation programs consisting of small populations are being used to keep this species from extinction. Fecal samples were collected from APCs in April 2007 and again in August 2008 from 2 separate captive propagation facilities in Texas after clinical signs of coccidiosis were observed. One Eimeria species was observed (Eimeria attwateri), which we describe as a putative new species. Sporulated oocysts are ellipsoidal, 30.0 × 18.4 (27.4-31.3 × 16.0-22.4) µm. Oocysts have a smooth wall 0.7 µm thick and lack both a micropyle and oocyst residuum, but 1 ellipsoidal polar granule is present, 2.3 × 1.9 (2.1-2.4 × 1.7-2.0) µm. Sporocysts have a nipple-like Stieda body with a rounded opposite end and are 14.0 × 7.1 (10.2-16.8 × 6.0-9.2) µm. The sporocysts contain a sporocyst residuum usually consisting of 2-4 dispersed globules, and each sporozoite contains 2 large posterior spheroid refractile bodies 3.4 µm wide. Nucleotide sequence amplified from the 18S rDNA does not match any DNA sequence information for publicly available Eimeria species, and phylogenetic reconstructions place this species with other eimerians from Galliformes. The discovery of a potentially pathogenic species of Eimeria in captive APCs is of great importance, and managers should be aware of the potential devastating effect(s) this parasite could have on the APC conservation programs. PMID:21506827

Fritzler, Jason M; Craig, Thomas M; Elgayar, Amal; Plummer, Casey; Wilson, R Steve; Peterson, Markus J; Zhu, Guan

2011-08-01

356

Margolisiella islandica sp. nov. (Apicomplexa: Eimeridae) infecting Iceland scallop Chlamys islandica (Müller, 1776) in Icelandic waters.  

PubMed

Wild Iceland scallops Chlamys islandica from an Icelandic bay were examined for parasites. Queen scallops Aequipecten opercularis from the Faroe Islands and king scallops Pecten maximus and queen scallops from Scottish waters were also examined. Observations revealed heavy infections of eimeriorine parasites in 95-100% of C. islandica but not the other scallop species. All life stages in the apicomplexan reproduction phases, i.e. merogony, gametogony and sporogony, were present. Trophozoites and meronts were common within endothelial cells of the heart's auricle and two generations of free merozoites were frequently seen in great numbers in the haemolymph. Gamonts at various developmental stages were also abundant, most frequently free in the haemolymph. Macrogamonts were much more numerous than microgamonts. Oocysts were exclusively in the haemolymph; live mature oocysts contained numerous (>500) densely packed pairs of sporozoites forming sporocysts. Analysis of the 18S ribosomal DNA revealed that the parasite from C. islandica is most similar (97.7% identity) to an unidentified apicomplexan isolated from the haemolymph of the giant clam, Tridacna crocea, from Japan. Phylogenetic analyses showed that the novel sequence consistently grouped with the Tridacna sequence which formed a robust sister clade to the rhytidocystid group. We propose the name Margolisiella islandica sp. nov., referring to both type host and type locality. PMID:21856309

Kristmundsson, Árni; Helgason, Sigurður; Bambir, Slavko H; Eydal, Matthías; Freeman, Mark A

2011-11-01

357

Previously unknown apicomplexan species infecting Iceland scallop, Chlamys islandica (Müller, 1776), queen scallop, Aequipecten opercularis L., and king scallop, Pecten maximus L.  

PubMed

Examination of three scallop species from three separate locations: Iceland scallop from Icelandic waters, king scallop from Scottish waters and queen scallop from Faroese and Scottish waters, revealed infections of a previously unknown apicomplexan parasite in all three scallop species. Developmental forms observed in the shells appeared to include both sexual and asexual stages of the parasite, i.e. merogony, gametogony and sporogony, which suggests a monoxenous life cycle. Meronts, gamonts, zygotes and mature oocysts were solely found in the muscular tissue. Zoites, which could be sporozoites and/or merozoites, were observed in great numbers, most frequently in muscles, both intracellular and free in the extracellular space. Zoites were also common inside haemocytes. Examination of the ultrastructure showed that the zoites contained all the major structures characterizing apicomplexans. This apicomplexan parasite is morphologically different from other apicomplexan species previously described from bivalves. Presently, its systematic position within the phylum Apicomplexa cannot be ascertained. PMID:21893066

Kristmundsson, Árni; Helgason, Sigurður; Bambir, Slavko Helgi; Eydal, Matthías; Freeman, Mark A

2011-11-01

358

CDPKs of Cryptosporidium parvum--stage-specific expression in vitro.  

PubMed

Cryptosporidium parvum is a zoonotic agent that bears a high risk for the health of particularly immunocompromised humans and animals. As currently available drugs and therapies against cryptosporidiosis do not turn out satisfactory, more intensive research on the control of this parasite is necessary. The genus Cryptosporidium is unique within the phylum Apicomplexa as its localisation is intracellular but extracytoplasmatic. Infection of host cells is initially a parasite-driven process, but the signalling events and their downstream actions within Cryptosporidium are poorly understood. Calcium-dependent protein kinases (CDPKs) are probably involved in the regulation of invasion and egress. Previously described in plants, algae and other Apicomplexa, CDPKs are not found in vertebrates. They are thus promising targets for pharmaceutical intervention. While CDPK1 is well characterised in Toxoplasma gondii (TgCDPK1) and Plasmodium falciparum (PfCDPK1), only little information exists about the expression and function of CDPK in C. parvum. Here, we describe results of the in silico analysis of seven CpCDPKs. Five CpCDPKs contain potential sites for N-myristoylation and N-palmitoylation. In a nested 3' rapid amplification of cDNA ends (RACE)-PCR, expression of six CpCDPKs resulted in distinct bands in infected cell cultures and extracts of freshly excysted sporozoites. The length of the 3' untranslated region (3' UTR) is described as well. Our results indicate CDPK expression to be stage specific on the mRNA level. PMID:24810092

Etzold, Manja; Lendner, Matthias; Daugschies, Arwid; Dyachenko, Viktor

2014-07-01

359

A Survey of Innovation through Duplication in the Reduced Genomes of Twelve Parasites  

PubMed Central

We characterize the prevalence, distribution, divergence, and putative functions of detectable two-copy paralogs and segmental duplications in the Apicomplexa, a phylum of parasitic protists. Apicomplexans are mostly obligate intracellular parasites responsible for human and animal diseases (e.g. malaria and toxoplasmosis). Gene loss is a major force in the phylum. Genomes are small and protein-encoding gene repertoires are reduced. Despite this genomic streamlining, duplications and gene family amplifications are present. The potential for innovation introduced by duplications is of particular interest. We compared genomes of twelve apicomplexans across four lineages and used orthology and genome cartography to map distributions of duplications against genome architectures. Segmental duplications appear limited to five species. Where present, they correspond to regions enriched for multi-copy and species-specific genes, pointing toward roles in adaptation and innovation. We found a phylum-wide association of duplications with dynamic chromosome regions and syntenic breakpoints. Trends in the distribution of duplicated genes indicate that recent, species-specific duplicates are often tandem while most others have been dispersed by genome rearrangements. These trends show a relationship between genome architecture and gene duplication. Functional analysis reveals: proteases, which are vital to a parasitic lifecycle, to be prominent in putative recent duplications; a pair of paralogous genes in Toxoplasma gondii previously shown to produce the rate-limiting step in dopamine synthesis in mammalian cells, a possible link to the modification of host behavior; and phylum-wide differences in expression and subcellular localization, indicative of modes of divergence. We have uncovered trends in multiple modes of duplicate divergence including sequence, intron content, expression, subcellular localization, and functions of putative recent duplicates that highlight the role of duplications in the continuum of forces that have shaped these genomes. PMID:24919110

DeBarry, Jeremy D.; Kissinger, Jessica C.

2014-01-01

360

Kelp Forests of the Santa Barbara Channel  

E-print Network

.......................................................................................iii Phylum Chlorophyta ­ Green Algae ............................................................ 1, Crabs .................................................... 36 Phylum Ectoprocta ­ Bryozoans

California at Santa Barbara, University of

361

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  

Microsoft Academic Search

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

Yuichi Hongoh; P. Deevong; S. Hattori; T. Inoue; S. Noda; N. Noparatnaraporn; T. Kudo; M. Ohkuma

2006-01-01

362

Microbial reductive dechlorination of aroclor 1260 in Baltimore harbor sediment microcosms is catalyzed by three phylotypes within the phylum Chloroflexi.  

PubMed

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

Fagervold, Sonja K; May, Harold D; Sowers, Kevin R

2007-05-01

363

Microbial Reductive Dechlorination of Aroclor 1260 in Baltimore Harbor Sediment Microcosms Is Catalyzed by Three Phylotypes within the Phylum Chloroflexi  

Microsoft Academic Search

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

Sonja K. Fagervold; Harold D. May; Kevin R. Sowers

2007-01-01

364

Report of wood decay fungus Inonotus tropicalis (phylum Basidiomycota) from a dog with a granulomatous mediastinal mass.  

PubMed

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

Sheppard, Barbara J; McGrath, Elizabeth; Giuffrida, Michelle; Craft, Serena L M; Kung, Chung Yee; Smith, Matthew E

2013-09-01

365

Spatiotemporal Changes in the Structure and Composition of a Less-Abundant Bacterial Phylum (Planctomycetes) in Two Perialpine Lakes ? †  

PubMed Central

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

Pollet, Thomas; Tadonléké, Rémy D.; Humbert, Jean François

2011-01-01

366

Candidatus Syngnamydia Venezia, a Novel Member of the Phylum Chlamydiae from the Broad Nosed Pipefish, Syngnathus typhle  

PubMed Central

Chlamydia are obligate intracellular bacteria and important pathogens of humans and animals. Chlamydia-related bacteria are also major fish pathogens, infecting epithelial cells of the gills and skin to cause the disease epitheliocystis. Given the wide distribution, ancient origins and spectacular diversity of bony fishes, this group offers a rich resource for the identification and isolation of novel Chlamydia. The broad-nosed pipefish (Syngnathus typhle) is a widely distributed and genetically diverse temperate fish species, susceptible to epitheliocystis across much of its range. We describe here a new bacterial species, Candidatus Syngnamydia venezia; epitheliocystis agent of S. typhle and close relative to other chlamydial pathogens which are known to infect diverse hosts ranging from invertebrates to humans. PMID:23951025

Schmidt-Posthaus, Heike; Nufer, Lisbeth; Wilson, Anthony; Svercel, Miroslav; Richter, Denis; Segner, Helmut; Pospischil, Andreas; Vaughan, Lloyd

2013-01-01

367

Carnets de Gologie / Notebooks on Geology -Article 2006/03 (CG2006_A03) Are the green algae (phylum Viridiplantae)  

E-print Network

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

Paris-Sud XI, Université de

368

Arcticibacter svalbardensis gen. nov., sp. nov., of the family Sphingobacteriaceae in the phylum Bacteroidetes, isolated from Arctic soil.  

PubMed

In the course of a study aimed at isolating bacteria from Arctic soils by a method that selectively enriches for rare bioactive actinomycetes, a Gram-stain-negative, pigmented, non-motile rod, designated MN12-7(T), was isolated. The salmon-pink strain was, based on 16S rRNA gene sequence similarity, found to be affiliated with the family Sphingobacteriaceae. Strain MN12-7(T) was catalase-, oxidase- and cellulase-positive and lacked gelatinase, urease, lipase and pectinase. The predominant cellular fatty acids were summed feature 3 (comprising C16?:?1?7c and/or C16?:?1?6c), iso-C15?:?0 and C15?:?1?6c. The major respiratory quinone of strain MN12-7(T) was MK-7, and the major polar lipid was phosphatidylethanolamine in addition to phosphatidylserine, seven unidentified lipids and six unidentified aminolipids. The DNA G+C content of strain MN12-7(T) was 38 mol%. Strain MN12-7(T) formed a separate lineage in a cluster containing 'Candidatus comitans', with which it shared 92.3?% 16S rRNA gene sequence similarity. Based on the phenotypic characteristics and phylogenetic inference, strain MN12-7(T) is proposed as a representative of a novel species in a new genus, Arcticibacter svalbardensis gen. nov., sp. nov. The type strain of the type species is MN12-7(T) (?=?KCTC 32015(T)?=?CIP 110422(T)). PMID:22904219

Prasad, Sathish; Manasa, B Poorna; Buddhi, Sailaja; Pratibha, Mambatta S; Begum, Zareena; Bandi, Sunil; Tirunagari, Preethi; Shivaji, Sisinthy

2013-05-01

369

Cloning and Molecular Characterization of the First Innexin of the Phylum Annelida—Expression of the Gene During Development  

Microsoft Academic Search

.   A novel member of the innexin family (cv-inx) has been isolated from the annelid polychaete worm Chaetopterus variopedatus using a PCR approach on genomic DNA and sequence analysis on genomic DNA clones. The gene is present in a HindIII-HindIII segment of 2250 bp containing an uninterrupted open reading frame of 1196 bp encoding a protein of 399 amino acids.

Nicoletta Potenza; Rosanna del Gaudio; Loredana Rivieccio; Giuseppina Maria Rosaria Russo; Giuseppe Geraci

2002-01-01

370

Draft Genome Sequence of Tatumella sp. Strain UCD-D_suzukii (Phylum Proteobacteria) Isolated from Drosophila suzukii Larvae  

PubMed Central

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

Dunitz, Madison I.; James, Pamela M.; Jospin, Guillaume; Coil, David A.; Chandler, James Angus

2014-01-01

371

Draft Genome Sequence of Tatumella sp. Strain UCD-D_suzukii (Phylum Proteobacteria) Isolated from Drosophila suzukii Larvae.  

PubMed

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

Dunitz, Madison I; James, Pamela M; Jospin, Guillaume; Eisen, Jonathan A; Coil, David A; Chandler, James Angus

2014-01-01

372

A NEW SPECIES OF EIMERIA (APICOMPLEXA: EIMERIIDAE) FROM THE EASTERN PIPISTRELLE, PERIMYOTIS SUBFLAVUS (CHIROPTERA: VESPERTILIONIDAE), IN ARKANSAS  

PubMed Central

During November 2009 and March 2010, 20 adult eastern pipistrelles, Perimyotis (=Pipistrellus) subflavus were collected from Polk County, Arkansas, and their feces examined for coccidian parasites. Two (10%) of the bats were found to be passing oocysts of an undescribed species of Eimeria. Oocysts of Eimeria heidti n. sp. were ovoidal to ellipsoidal, 26.1 × 20.5 (23-31 × 18-23) ?m, with a bilayered wall, externally rough, internally smooth, and with a shape index of 1.3. Micropyle and oocyst residuum were absent, but a subspherical polar granule was often present. Sporocysts were ovoidal, 13.0 × 8.8 (11-15 × 7-13) ?m, the shape index was 1.6, a Stieda body was present and sub-Stieda and para-Stieda bodies were absent. A sporocyst residuum consisting of multiple globules dispersed along the perimeter of the sporocyst and between the sporozoites were present, sporozoites were elongate, with a subspherical anterior refractile body and elongate posterior refractile body; a nucleus not discernable. This is the second coccidian reported from this host and the fourth instance of a coccidian species reported from an Arkansas bat. PMID:21506799

McAllister, Chris T.; Burt, Scott; Seville, R. Scott; Robison, Henry W.

2011-01-01

373

Comparison of the ITS1 and ITS2 rDNA in Eimeria callospermophili (Apicomplexa:Eimeriidae) from sciurid rodents.  

PubMed

The taxonomy of the coccidia has historically been morphologically based. The purpose of this study was to establish if conspecificity of isolates of Eimeria callospermophili from 4 ground-dwelling squirrel hosts (Rodentia: Sciuridae) is supported by comparison of rDNA sequence data and to examine how this species relates to eimerian species from other sciurid hosts. Eimeria callospermophili was isolated from 4 wild-caught hosts, i.e., Urocitellus elegans, Cynomys leucurus, Marmota flaviventris , and Cynomys ludovicianus . The ITS1 and ITS2 genomic rDNA sequences were PCR generated, sequenced, and analyzed. The highest intraspecific pairwise distance values of 6.0% in ITS1 and 7.1% in ITS2 were observed in C. leucurus. Interspecific pairwise distance values > 5% do not support E. callospermophili conspecificity. Generated E. callospermophili sequences were compared to Eimeria lancasterensis from Sciurus niger and Sciurus niger cinereus and to Eimeria ontarioensis from S. niger. A single, well-supported clade was formed by E. callospermophili amplicons in neighbor joining and maximum parsimony analyses. However, within the clade, there was little evidence of host or geographic structuring of the species. PMID:21506777

Motriuk-Smith, Dagmara; Seville, R Scott; Quealy, Leah; Oliver, Clinton E

2011-04-01

374

Comparison of the ITS1 and ITS2 rDNA in Emeria callospermophili (Apicomplexa: Eimeriidae) from Sciurid Rodents  

PubMed Central

The taxonomy of the coccidia has historically been morphologically based. The purpose of this study was to establish if conspecificity of isolates of Eimeria callospermophili from 4 ground-dwelling squirrel hosts (Rodentia: Sciuridae) is supported by comparison of rDNA sequence data and to examine how this species relates to eimerian species from other sciurid hosts. Eimeria callospermophili was isolated from 4 wild caught hosts, i.e., Urocitellus elegans, Cynomys leucurus, Marmota flaviventris, and Cynomys ludovicianus. The ITS1 and ITS2 genomic rDNA sequences were PCR generated, sequenced, and analyzed. The highest intraspecific pairwise distance values of 6.0% in ITS1 and 7.1% in ITS2 were observed in C. leucurus. Interspecific pairwise distance values greater than 5% do not support E. callospermophili conspecificity. Generated E. callospermophili sequences were compared to Eimeria lancasterensis from Sciuris niger and Sciurus niger cinereus, and Eimeria ontarioensis from S. niger. A single well-supported clade was formed by E. callospermophili amplicons in Neighbor Joining and Maximum Parsimony analyses. However, within the clade there was little evidence of host or geographic structuring of the species. PMID:21506777

Motriuk-Smith, Dagmara; Seville, R Scott; Quealy, Leah; Oliver, Clinton E.

2011-01-01

375

Monoclonal antibodies specific for the two types of wall-forming bodies of Eimeria tenella macrogametes (Coccidia, Apicomplexa)  

Microsoft Academic Search

Two monoclonal antibodies (mAbs) raised against the macrogamonts of Eimeria tenella identified antigens located in the wall-forming bodies of type I (WF I) and type II (WF II) by indirect immunofluorescence and by immunoelectron microscopy. With these mAbs, the involvement of both types of wall-forming body at the protein level in the formation of the inner and outer oocyst walls

Aimdip Noutossi Mouafo; Andreas Weck-Heimann; Jean-François Dubremetz; Rolf Entzeroth

2002-01-01

376

Chimeric fluorescent reporter as a tool for generation of transgenic Eimeria (Apicomplexa, Coccidia) strains with stage specific reporter gene expression.  

PubMed

Progress in transfection of Eimeria sporozoites leads to transformed oocysts, however the output of mutants after passages in the host animals is low. Further enrichment of transgenic oocysts was dependent on fluorescent activated cell sorting and could not be achieved by drug selection. In this study, we fused the Toxoplasma gondii DHFR-TSm2m3 pyrimethamine resistance gene with the yellow fluorescent protein (YFP) encoding sequence to provide continuous pyrimethamine resistance and fluorescence in the Eimeria parasite from a single transcript. The permanent YFP signal of transgenic parasites allows differentiating transgenic parasites from wild type parasites throughout the entire life cycle. The output of transformed oocysts increased up to more than 30% after initial transfection and completion of the life cycle in the host animal. Within three passages under pyrimethamine treatment, a strain with 100% transformed sporulated oocysts of the parasite could be isolated. This new method provides the potential to produce and monitor transgenic Eimeria strains without additional fluorescence activated cell sorting (FACS). The chimeric fluorescent reporter can be utilized as a continuous internal control for plasmids containing stage specific promoter. By this means we utilized an Eimeria tenella gamogony gene specific regulatory sequence to confer macrogamont specific tandem dimer tomato (tdtomato) reporter gene expression in Eimeria nieschulzi. PMID:22449589

Hanig, Sacha; Entzeroth, Rolf; Kurth, Michael

2012-09-01

377

A new species of coccidia (Apicomplexa: Eimeriidae) from Cordillera striped shrew-rat, Chrotomys whiteheadi (Rodentia: Muridae), from the Philippines.  

PubMed

During July 2011, a single Cordillera striped shrew-rat (Chrotomys whiteheadi) was collected from the Philippines and its faeces examined for coccidian parasites. It harboured an eimerian that we describe here as new. Oocysts of Eimeria macarthuri sp. n. were spheroidal to subspheroidal with a bi-layered wall and measured (length × width, L × W) 18.2 × 17.0 ?m, with an L/W ratio of 1.1. A micropyle, oocyst residuum and polar granule were absent. Sporocysts were ovoidal, 9.0 × 6.4 ?m, with an L/W ratio of 1.3. A nipple-like Stieda body was present as well as a substieda body. A granular sporocyst residuum was present. To our knowledge, E. macarthuri represents the only coccidian ever described from a rodent of the Philippines. PMID:25236280

McAllister, Chris T; Seville, R Scott; Duszynski, Donald W; Bush, Sarah E

2014-10-01

378

Two new species of Isospora (Apicomplexa: Eimeriidae) from skinks Emoia spp. (Sauria: Scincidae), from Fiji and Papua New Guinea  

USGS Publications Warehouse

Between September and October 1991 and again during September 1992, skinks (Emoia spp.) were collected from various localities on Fiji and Papua New Guinea (PNG) and examined for coccidians. One of 4 (25%) De Vis' emo skinks (Emoia pallidiceps) from PNG harbored an undescribed species of Isospora in its feces. Oocysts of Isospora grinbikpelapalai n. sp. were ellipsoidal to subspheroidal, 18.1 × 14.9 (17–20 × 14–16) ?m, with a bilayered wall and a length/width index (L/W) of 1.2. Both micropyle and oocyst residuum were absent, but a prominent polar granule was present. Sporocysts were ovoidal, 10.7 × 7.6 (10–11 × 7–8) ?m, with a L/W index of 1.4. Stieda and sub-Stieda bodies were present, but para-Stieda bodies were absent. The sporocyst residuum consisted of large scattered globules dispersed between sporozoites. Sporozoites were elongate with spheroidal anterior and posterior refractile bodies. Isospora grinbikpelapalai was also found in 1 of 2 (50%) Pope's emo skinks (Emoia popei) from PNG. One of 13 (8%) white-bellied copper-striped skinks (Emoia cyanura), from Fiji, was passing another undescribed species of Isospora in its feces. Oocysts of Isospora casei n. sp. were elongate, 31.8 × 21.3 (28–35 × 18–24) ?m, with a bilayered wall and a L/W index of 1.5. Micropyle, oocyst residuum, and polar granule were all absent. Sporocysts were ovoidal, 15.3 × 10.6 (14–16 × 10–12) ?m, with a L/W index of 1.4. Stieda and sub-Stieda bodies were present, but para-Stieda bodies were absent. The sporocyst residuum consisted of scattered globules among sporozoites or as a cluster surrounding sporozoites. Sporozoites were elongate with spheroidal anterior and posterior refractile bodies. Isospora casei was also found in 1 of 2 (50%) Fiji slender treeskinks (Emoia concolor) from Fiji. This represents the first report of coccidia from Emoia spp. and, to our knowledge, the initial documentation of reptilian coccidia from herpetofauna from Papua New Guinea.

McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.

2013-01-01

379

Morphologic and molecular characterization of the sarcocysts of Sarcocystis rileyi (Apicomplexa: Sarcocystidae) from the mallard duck ( Anas platyrhynchos ).  

PubMed

Macroscopic sarcocysts are often observed in ducks, but at present their taxonomic status remains uncertain because ducks serve as intermediate hosts for several such parasites in the genus Sarcocystis . One such species, Sarcocystis rileyi , was long ago established to involve the northern shoveler duck ( Anas clypeata ) and the striped skunk ( Mephitis mephitis ) as its intermediate and definitive hosts, respectively. Here, we employed light microscopy, electron microscopy, and DNA sequencing to more precisely describe diagnostic attributes of parasites presumed to represent S. rileyi occurring in a naturally-infected mallard duck ( Anas platyrhynchos ). By light and transmission electron microscopy, sarcocysts from the mallard duck resembled the S. rileyi described from A. clypeata . We document 18S, ITS-1, and 28S rDNA sequences from the mallard duck, the first for S. rileyi from any host. Sequences of conserved and variable portions of nuclear ribosomal DNA indicated that S. rileyi is related to, but distinct from, parasites employing opossums as their definitive host (including Sarcocystis neurona and Sarcocystis falcatula ). Diagnostic ultrastructural features and nucleotide sequences should aid in future studies and communications regarding this parasitic taxon, which lends itself to experimentation because its sarcocysts are macroscopic and easily excised from infected birds. PMID:20496959

Dubey, J P; Rosenthal, B M; Felix, T A

2010-08-01

380

New host and locality records of coccidia (Apicomplexa: Eimeriidae) from rodents in the southwestern and western United States.  

PubMed

One hundred forty-seven murid and heteromyid rodents were collected from various sites in the southwestern and western United States (Arizona, Colorado, New Mexico, Texas, and Utah) and Baja California Norte, Mexico, and their feces were examined for coccidial parasites. Of these, 53 (36%) were infected with at least 1 coccidian; 45 of 53 (85%) of the infected rodents harbored only 1 species of coccidian. Infected rodents included: 10 of 22 (45%) Neotoma albigula, 3 of 11 (27%) Neotoma floridana, 2 of 14 (14%) Neotoma lepida, 15 of 29 (52%) Neotoma micropus, 5 of 8 (63%) Peromyscus crinitis, 6 of 6 (100%) Peromyscus difficilis, 1 of 2 (50%) Peromyscus eremicus, 9 of 34 (26%) Sigmodon hispidis, and 2 of 3 (67%) Sigmodon ochrognathus; 4 Neotoma cinerea, 3 Neotoma devia, 3 Neotoma mexicana, 1 Peromyscus maniculatus, 1 Onychomys leucogaster, 1 Onychomys torridus, 3 Chaetodipus fallax, and 2 Chaetodipus penicillatus were negative. Although no new species was found, the following coccidians were identified from infected rodents: Eimeria albigulae from N. albigula, N. floridana, and N. micropus, Eimeria antonellii from N. albigula and N. micropus, Eimeria ladronensis from N. albigula, N. floridana, N. lepida, and N. micropus, Eimeria arizonensis and Eimeria lachrymalis from P. crinitis and P. difficilis, Eimeria lachrymalis from P. eremicus, Eimeria tuskeegensis from S. ochrognathus, and Eimeria roperi, Eimeria sigmodontis, Eimeria tuskeegensis, Eimeria webbae, and an unidentified species of Eimeria from S. hispidis. This report documents 12 new host and several distributional records for Eimeria species from murid rodents in Arizona, Texas, and Utah. PMID:1779282

McAllister, C T; Upton, S J; Planz, J V; DeWalt, T S

1991-12-01

381

Cryptosporidium viatorum n. sp. (Apicomplexa: Cryptosporidiidae) among travellers returning to Great Britain from the Indian subcontinent, 2007-2011.  

PubMed

A novel Cryptosporidium genotype was identified, among travellers with gastro-intestinal symptoms returning to Great Britain from the Indian subcontinent, for which we propose the name Cryptosporidium viatorum n. sp. The epidemiology of these cases was distinctly different from those with Cryptosporidium parvum and Cryptosporidium hominis. Of the 10 cases identified involving C. viatorum, most were in the first quarter of the year. One occurred in 2007, one in 2008, three in 2010 and five to end March 2011. The median age was 19 years but most were in the 20-29 years age group and seven were male. The symptoms included diarrhoea, abdominal pain, nausea, vomiting and fever. Compared with cases due to C. hominis and C. parvum, vomiting was reported less often, although the duration of gastro-intestinal symptoms was longer. The cases of C. viatorum were all travellers to the Indian subcontinent, whereas cases of C. hominis and C. parvum were more likely to have travelled elsewhere. Cryptosporidium viatorum isolates had indistinguishable sequences at each of the 70 kDa heat shock protein (HSP70), actin and ssrRNA loci which did not match any published previously and, although phylogenetically most similar to Cryptosporidium fayeri, they were distinct (<98% similarity) at the ssrRNA, HSP70 and actin genes. Morphologically, oocysts were typical of predominantly human-infecting species. Cryptosporidium viatorum n. sp. is proposed and work is warranted to investigate further the public health significance and occurrence elsewhere of this emerging parasite. PMID:22633952

Elwin, Kristin; Hadfield, Stephen J; Robinson, Guy; Crouch, Nigel D; Chalmers, Rachel M

2012-06-01

382

Redescription and molecular diagnosis of Hepatozoon theileri (Laveran, 1905) (Apicomplexa: Adeleorina: Hepatozoidae), infecting Amietia quecketti (Anura: Pyxicephalidae).  

PubMed

Blood smears prepared from the peripheral blood of 20 wild caught Amietia quecketti (Boulenger) from the North-West University Botanical Gardens, North West Province, South Africa, were examined for the presence of haemogregarines. A haemogregarine species comparative in morphology, host and geographical locality to that of Haemogregarina theileri Laveran, 1905 was detected. The original description of H. theileri was based solely on frog peripheral blood gamont stages. Later, further parasite stages, including trophozoites and merogonic liver stages, were recorded in a related Amietia sp. from equatorial Africa. This species was originally classified as a member of the genus Haemogregarina Danilewsky, 1885, but due to the close life cycle and morphological resemblance to those of Hepatozoon species, H. theileri was later transferred from Haemogregarina to Hepatozoon Miller, 1908. In the present study, meront and merozoite stages not described before, along with previously observed trophozoite, immature and mature gamont stages, are described from the peripheral blood of hosts. In addition, comparative phylogenetic analysis of the partial 18S rDNA sequence of Hepatozoon theileri to those of other haemogregarine species, including those of species of Hepatozoon and a Haemogregarina, support the taxonomic transfer of H. theileri to Hepatozoon, nesting H. theileri within a clade comprising species parasitising other amphibians. This is the first molecular and phylogenetic analysis of an African anuran species of Hepatozoon. PMID:25185400

Netherlands, Edward C; Cook, Courtney A; Smit, Nico J; du Preez, Louis H

2014-08-01

383

A NEW SPECIES OF HEPATOZOON (APICOMPLEXA: ADELEORINA) FROM PYTHON REGIUS (SERPENTES: PYTHONIDAE) AND ITS EXPERIMENTAL TRANSMISSION BY A MOSQUITO VECTOR  

Microsoft Academic Search

Hepatozoon ayorgbor n. sp. is described from specimens of Python regius imported from Ghana. Gametocytes were found in the peripheral blood of 43 of 55 snakes examined. Localization of gametocytes was mainly inside the erythrocytes; free gametocytes were found in 15 (34.9%) positive specimens. Infections of laboratory-reared Culex quinquefasciatus feeding on infected snakes, as well as experimental infection of juvenile

Michal Sloboda; Martin Kamler; Jana Bulantová; Jan Votýpka; David Modrý

2007-01-01

384

The role of gamont entry into erythrocytes in the specificity of Hepatozoon species (Apicomplexa: Adeleida) for their frog hosts.  

PubMed

Hepatozoon species are apicomplexan parasites that infect blood cells and viscera of terrestrial vertebrates. One species, Hepatozoon clamatae, primarily infects green frogs, Rana clamitans , whereas another, Hepatozoon catesbianae, primarily infects bullfrogs, Rana catesbeiana , although both species of parasite are capable of infecting either species of frog. The aim of this study was to determine whether the basis for this partial host specificity is manifested at the gamont, or intraerythrocytic, stage of the parasite's life cycle. Blood was drawn from infected frogs and treated in vitro with a saline solution to induce intracellular gamonts to emerge from host erythrocytes. This treated blood was added to in vitro samples of uninfected blood of green frogs and bullfrogs. After 1 hr, samples were analyzed to determine the level of re-entry of the parasites into uninfected erythrocytes. Results obtained using multiple combinations of donor and recipient frogs indicate that extracellular gamonts of both parasite species do not exhibit preference for erythrocytes of 1 frog species over those of another. These results suggest that the basis for the observed host specificity is not determined at the gamont stage and is more likely dependent on another stage in the parasite life cycle. PMID:23829695

Dickson, Cory M; Ogbuah, Christopher T; Smith, Todd G

2013-12-01

385

Plasmodium, Saurocytozoon and Haemocystidium parasites (Apicomplexa: Plasmodiidae) from the rock agama, Laudakia caucasia (Sauria: Agamidae), in southern Asia.  

PubMed

The rock agama, Laudakia caucasia Eichwald (Agamidae) is host to Plasmodium caucasica sp. n. and Saurocytozoon agamidorum sp. n. in western Pakistan. Plasmodium caucasica is characterized by very large meronts, 11-21 by 8-17 microm that produce 32-67 merozoites, which nearly fill the host erythrocyte, and smaller, ovoid to elongate gametocytes, 6-14 by 2.5-6 microm, with length by width (LW) 21-55 microm2, and L/W ratio 1.0-4.0. Host cells are usually mature erythrocytes. In Azerbaijan, P. caucasica parasitizes immature erythroid cells. Dimensions of meronts are 10-16 by 6-12 microm, and merozoite numbers are 12-44. Gametocytes are 6-14 by 3-6 microm, with LW 31-56 microm2, and L/W ratio 1.0-4.0. Saurocytozoon agamidorum sp. n. gametocytes are 6.5-13 microm in diameter, with LW 35-79 microm2, and L/W ratio 1.0-2.2. They occupy lymphocytes as host cells, which are greatly distorted by gametocyte presence and often show nuclei nearly divided into two portions, one portion at each end of the cell. Haemocystidium grahami (Shortt, 1922), redescribed from material found in L. caucasia from Azerbaijan, has rounded to elongate gametocytes, 8-19.5 by 4-8 microm, LW 60.5-102 microm2, and L/W ratio 1.0-4.5. The prominent light golden pigment granules often coalesce to nearly cover the surface of the gametocyte. The presence of P. caucasica and S. agamidorum extends the range of the two genera in saurian hosts throughout much of the southern Asia mainland. PMID:23951929

Telford, Sam R

2013-07-01

386

Microscopic and molecular characterization of Hepatozoon domerguei (Apicomplexa) and Foleyella furcata (Nematoda) in wild endemic reptiles from Madagascar  

PubMed Central

Madagascar is one of the world’s top twelve “megadiversity” hot spots hosting unique and threatened flora and fauna. Parasites are a major component of biodiversity but remain largely uncharacterized in wildlife. In this study we combine microscopic and molecular assessment of hemoparasites in endemic reptile species from Madagascar. We detected three distinct parasites: the apicomplexans Hepatozoon and Sarcocystis, and filarial nematodes. The prevalence and intensity of these apicomplexans were low overall, while microfilarial infections in chameleons were relatively high. We detected mixed infections of two Hepatozoon haplotypes in Madagascarophis colubrinus, and of Hepatozoon and microfilariae in a Furcifer sp. Phylogenetic analyses of Hepatozoon showed evidence of prey-predator transmission, with identical sequences found in the snakes M. colubrinus and Ithycyphus oursi, and their prey Furcifer sp. Based on previous studies regarding the life cycle of Hepatozoon domerguei Landau, Chabaud, Michel, and Brygoo, 1970 in these hosts and due to their morphological similarity, we propose that this Hepatozoon haplotype is Hepatozoon domerguei. Future studies, including the examination of invertebrate hosts, are needed to verify this preliminary taxonomic identification. A distinct hemogregarine haplotype was found in Oplurus sp., which displayed morphologically different gametocytes, some of which were apparently inside leukocytes. The Sarcocystis identified from Tracheloptychus petersi was identical to that reported in a North African snake, indicating that the same lineage is found in geographically distinct regions. By combining morphological and genetic information, Foleyella furcata (Linstow, 1899) filarial nematodes were identified in several Furcifer chameleons. This study provides insights into the distribution, diversity and host-parasite interactions of hemoparasites in wild reptile populations from Madagascar. PMID:25224723

Maia, Joao P.; Crottini, Angelica; Harris, David James

2014-01-01

387

A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from Carlia spp. (Sauria: Scincidae) from Papua New Guinea  

USGS Publications Warehouse

A new species of Eimeria Schneider, 1875 from rainbow skinks, Carlia ailanpalai Zug and Carlia eothen Zug is described from specimens collected in Papua New Guinea (PNG). Oöcysts of Eimeria zugi n. sp. from one of one (100%) C. eothen are ellipsoidal to cylindroidal, with a smooth, colourless, bi-layered wall, measure 25.1 × 15.5 ?m and have a length/width ratio of 1.6. The micropyle and the oöcyst residuum are absent, but a polar granule is present. The sporocysts are ovoidal to ellipsoidal and 10.3 × 7.1 ?m in size and do not contain Stieda, sub-Stieda or para-Stieda bodies; and the sporocyst residuum is composed of a compact mass of large globules. The sporozoites are elongate, 12.8 × 2.9 ?m in size, and contain anterior and posterior refractile bodies with a nucleus between them. This is the ninth species of coccidium described from skinks from PNG, and the new species described herein is apparently endemic to the skink genus Carlia (Gray).

McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.; Austin, Christopher C.

2013-01-01

388

Exogenous stages of Eimeria bemricki n. sp. (Apicomplexa: Eimeriidae) from the great gray owl, Strix nebulosa (Foster).  

PubMed

Exogenous stages of a new species of Eimeria are described from feces of a captive great gray owl, Strix nebulosa, held at the Gabbert Raptor Center, University of Minnesota, St. Paul, Minnesota. Oocysts (n = 100) of Eimeria bemricki are spherical to subspherical, 19.2 x 19.0 (21.5-16.0 x 21.0-16.0) microm, with ovoidal sporocysts (n = 100), 10.0 x 6.5 (12.0-7.0 x 7.0-5.5) microm and sporozoites (n = 20), 8.2 x 3.2 (6.8-10.1 x 2.5-3.9) microm. Stieda bodies, substieda bodies, polar bodies, and sporocyst residua are present, but micropyle, oocyst residuum, and parastieda bodies are absent. Three refractile bodies are contained in each sporozoite. PMID:9794640

Averbeck, G A; Cooney, J D; Guarnera, T R; Redig, P; Stromberg, B E

1998-10-01

389

Experimental infection of adult and juvenile coyotes with domestic dog and wild coyote isolates of Hepatozoon americanum (Apicomplexa: Adeleorina).  

PubMed

Each of five adult and four juvenile coyotes (Canis latrans) was exposed to an oral dose of 50 Hepatozoon americanum oocysts recovered from Amblyomma maculatum ticks that previously fed on either naturally infected domestic dogs (Canis familiaris) or naturally infected wild coyotes. All coyotes exposed to H. americanum became infected, regardless of isolate source, and all exhibited mild to moderate clinical disease that simulated American canine hepatozoonosis in naturally infected dogs. At 100 days postexposure, parasitemia was greater in juvenile than adult coyotes (0.9% and 0.3%, respectively); radiographic imaging of femurs revealed moderate exostosis in all juveniles and mild to moderate new bone growth in four of five (80%) adult coyotes. Gross postmortem analysis of bone lesions demonstrated variation between age groups of coyotes but not between isolates of H. americanum. Microscopic evaluation of skeletal muscle revealed that parasite-induced lesions were significantly more numerous (t = 5.0, df = 7, P = 0.001) in juvenile than adult coyotes. Results of this study indicate that juvenile and adult coyotes are equally susceptible to experimental infection with H. americanum isolated from domestic dog and wild coyote sources. The age of coyotes at the time of exposure, and possibly the number of H. americanum oocysts ingested, might influence morbidity and mortality, but it appears that both adult and juvenile coyotes could be reservoirs of H. americanum. PMID:16244069

Garrett, Jennifer Jane; Kocan, A Alan; Reichard, Mason V; Panciera, Roger J; Bahr, Robert J; Ewing, Sidney A

2005-07-01

390

A revision of the taxonomy and nomenclature of the Eimeria spp. (Apicomplexa: Eimeriidae) from rodents in the Tribe Marmotini (Sciuridae)  

Microsoft Academic Search

All published papers on Eimeria spp. from rodents in the Marmotini Tribe are reviewed and each described species is evaluated in an historical context (i.e., beginning with the oldest description). Many of these species descriptions from marmotine rodents are invalid when considered within either the spirit or the letter of the International Code of Zoological Nomenclature. In addition, several previous

Patricia G. Wilber; D. W. Duszynski; S. J. Upton; R. S. Seville; J. O. Corliss

1998-01-01

391

A new species of Eimeria (Apicomplexa: Eimeriidae) from the northern myotis, Myotis septentrionalis (Chiroptera: Vespertilionidae), in Oklahoma.  

PubMed

During September 2004, 4 adult northern myotis, Myotis septentrionalis, were collected from LeFlore County, Oklahoma (n ?=? 2), and Logan (n ?=? 1) and Yell (n ?=? 1) counties, Arkansas, and their feces examined for coccidian parasites. Three of 4 bats (75%) were passing oocysts of Eimeria spp. Oocysts of Eimeria tumlisoni n. sp. were subspherical, 17.6 × 16.8 (16-19 × 14-18) µm with a shape index of 1.0 (1.0-1.1). A micropyle and oocyst residuum were absent, although 1-2 bilobed polar granules were often present. Sporocysts were ovoidal, 10.5 × 5.9 (9-12 × 5-7) µm with a shape index of 1.8 (1.6-2.0). A Stieda body was present, but substieda and parastieda bodies were absent. A sporocyst residuum was present consisting of compact to dispersed granules between the sporozoites. The sporozoites were elongate, with subspherical anterior refractile body and spherical posterior refractile body; a nucleus was not discernable. This is the second coccidian reported from this host and the first instance of a bat coccidian reported from Oklahoma. We also document a new geographic record for Eimeria catronensis in Oklahoma and provide an emended description. PMID:22509940

McAllister, Chris T; Seville, R Scott; Roehrs, Zachary P

2012-10-01

392

A NEW SPECIES OF EIMERIA (APICOMPLEXA: EIMERIIDAE) FROM THE NORTHERN MYOTIS, MYOTIS SEPTENTRIONALIS (CHIROPTERA: VESPERTILIONIDAE), IN OKLAHOMA  

PubMed Central

During September 2004, 4 adult northern myotis, Myotis septentrionalis, were collected from LeFlore County, Oklahoma (n = 2), and Logan (n = 1) and Yell (n = 1) counties, Arkansas, and their feces examined for coccidian parasites. Three of 4 bats (75%) were passing oocysts of Eimeria spp. Oocysts of Eimeria tumlisoni n. sp. were ovoidal, 17.6 × 16.8 (16–19 × 14–18) ?m with a shape index of 1.0 (1.0–1.1). A micropyle and oocyst residuum were absent, although 1–2 bilobed polar granules were often present. Sporocysts were ovoidal, 10.5 × 5.9 (9–12 × 5–7) ?m with a shape index of 1.8 (1.6–2.0). A Stieda body was present, but sub–Stieda and para–Stieda bodies were absent. A sporocyst residuum was present consisting of compact to dispersed granules between the sporozoites. The sporozoites were elongate, with subspherical anterior refractile body and spherical posterior refractile body; a nucleus was not discernable. This is the second coccidian reported from this host and the first instance of a bat coccidian reported from Oklahoma. We also document a new geographic record for Eimeria catronensis in Oklahoma, and provide an emended description. PMID:22509940

McAllister, Chris T.; Seville, R. Scott; Roehrs, Zachary P.

2012-01-01

393

Coccidia (Apicomplexa: Eimeriidae) Infecting Cricetid Rodents from Alaska, U.S.A., and Northeastern Siberia, Russia, and Description of a  

E-print Network

); 116/159 (73%) Microtus pennsylvanicus (E. saxei, E. wenrichi); 9/52 (17%) Microtus xanthognathus (E infections: 15/72 (21%) Lemmus trimucronatus (Eimeria spp. 3, 4, 5); 10/29 (34%) Microtus longicaudus (Eimeria saxei, Eimeria wenrichi); 41/88 (47%) Microtus miurus (Eimeria coahiliensis, Eimeria ochrogasteri

394

A new species of Caryospora (Apicomplexa: Eimeriidae) from the sharp-shinned hawk, Accipiter striatus (Aves: Accipitriformes).  

PubMed

An injured juvenile sharp-shinned hawk, Accipiter striatus Vieillot, 1807 (Aves: Accipitriformes), housed and treated at the College of Veterinary Medicine Teaching Hospital at Kansas State University, Manhattan, Kansas, USA, was found to be passing oocysts of an undescribed species of Caryospora in its feces. Sporulated oocysts of Caryospora petersoni n. sp. were subspherical, with a bilayered wall, and they measured 43.1 × 39.8 ?m; micropyle, oocyst residuum, and polar granule were absent. Sporocysts were subspherical to spherical, 23.4 × 23.3 ?m; Stieda, substieda, and parastieda bodies were absent, but a spherical sporocyst residuum was present as a compact mass, ~15.1 ?m wide, composed of many homogeneous globules. The new species represents the first caryosporan documented from this species of hawk. PMID:23098064

McAllister, Chris T; Duszynski, Donald W; McKown, Richard D

2013-06-01

395

A NEW SPECIES OF CARYOSPORA (APICOMPLEXA: EIMERIIDAE) FROM THE FLATHEAD SNAKE, TANTILLA GRACILIS (OPHIDIA: COLUBRIDAE), IN SOUTHEASTERN OKLAHOMA  

PubMed Central

A single flathead snake, Tantilla gracilis, collected in early October 2010 from Choctaw County, Oklahoma, was found to harbor an undescribed species of Caryospora. Oocysts of Caryospora choctawensis n. sp. were spherical to subspherical, 15.8 × 15.0 (14–18 × 14–16) ?m with a thick bilayered wall and a shape index (length/width) of 1.1. A micropyle and an oocyst residuum are absent but prominent Stieda and bubble-like sub-Stieda bodies were present as well as a bilobed polar granule near the oocyst wall. Sporocysts were ovoidal, 10.8 × 9.0 (10–12 × 8–9) ?m with a shape index of 1.3. The sporocyst residuum was spherical and composed of a cluster of granules often membrane-bound. This is the second time a caryosporan species has been reported from T. gracilis, but the first coccidian ever described from a reptilian host in Oklahoma. Additional T. gracilis from Arkansas (n = 6), Oklahoma (n = 1), and Texas (n = 7) were examined and a single specimen from Newton County, Arkansas, harbored Caryospora gracilis Upton, McAllister, Trauth, and Bibb, 1992, previously reported from T. gracilis collected in Arkansas and Texas. PMID:22191621

McAllister, Chris T.; Roehrs, Zachary P.; Seville, R. Scott

2012-01-01

396

Two additional Hepatozoon species (Apicomplexa: Hepatozoidae) from the southern black racer, Coluber constrictor priapus (Serpentes: Colubridae), in northern Florida.  

PubMed

Hepatozoon priapus n. sp. from Coluber constrictor priapus has robust gamonts with broadly rounded ends, 18.0 x 4.2 microm (17.0-20.0 x 3.5-6.0), with LW 76.4 microm2 (59-105) and L/W 4.31 (2.9-5.4). The nucleus is always present in second quarter of gamont, seldom extend into first quarter but often into third quarter, 6.0 x 3.0 (5.0-7.0 x 2.5-4.0), with LW 17.9 (13.7-21.0). Erythrocyte cytoplasm is always thin, appearing dehemoglobinized, with infected cells always distorted. Infected erythrocytes are much longer and wider than uninfected cells, with longer nuclei. Oocysts are spherical to ovoid, 92.5 x 86.0 (55-123 x 47-115) and L/W 1.08 (1.0-1.3), contain 14.0 (6-31) sporocysts. Sporocysts, which are also spherical to ovoid, 26.3 x 23.3 (19-50 x 16-38), LW 641.2 (320-1,500) and L/W 1.13 (1.0-2.2), contain 12.6 (5-18) sporozoites. Hepatozoon confusus n. sp., also from C. constrictor priapus, has slender gamonts with rounded ends, 15.6 x 4.1 (14.0-17.0 x 3.5-5.0), with LW 64.3 (52-80) and L/W 3.82 (2.8-4.4). The nucleus is always present in second quarter of gamont, commonly extending into first and third quarters, 5.0 x 2.7 (2.5-4.4 x 4.0-6.0), with LW 13.5 (11.0-16.5). Erythrocyte cytoplasm is sometimes thin, appearing partially dehemoglobinized, with infected cells usually distorted. Infected erythrocytes are longer than uninfected cells but similar in width, with erythrocyte nuclei longer. Oocysts are spherical to ovoid, 115.5 x 108.9 (52-278 x 50-278), with L/W 1.06 (1.0-1.2), and contain 25.0 (7-111) sporocysts. Sporocysts are spherical to ovoid, 27.6 x 25.2 (21-38 x 20-33), LW 701.3 (420-1,125) and L/W 1.09 (1.0-1.4), containing 20.2 (12-32) sporozoites. PMID:15856888

Telford, Sam R; Butler, J F; Moler, Paul E

2005-02-01

397

Two new species of Eimeria (Apicomplexa: Eimeriidae) from eastern red bats, Lasiurus borealis (Chiroptera: Vespertilionidae), in Arkansas and North Carolina.  

PubMed

During August 2003 and August 2004, 11 adult eastern red bats, Lasiurus borealis, were collected and their feces examined for coccidian parasites. Bats were obtained in August 2003 from Garland, Montgomery, and Yell counties, Arkansas (n=6) and in August 2004 from Anson and Montgomery counties, North Carolina (n=5). Seven (63.6%) of the bats were passing oocysts of 2 undescribed species of Eimeria. Oocysts of Eimeria dowleri n. sp. were subspherical to ellipsoidal, 24.7 x 22.0 (23-26 x 20-23) microm, with a bilayered wall, externally moderately pitted, internally smooth, and with a shape index of 1.1. Micropyle and oocyst residuum were absent, but a polar granule was present. Sporocysts were ovoidal, 13.4 x 9.2 (12-14 x 8-9) pm; shape index was 1.5; Stieda and sub-Stieda bodies were present. A sporocyst residuum consisting of homogeneous granules was scattered among the sporozoites; sporozoites were elongate, with a subspherical anterior refractile body and an elongate posterior refractile body; a nucleus was not discernable. Oocysts of Eimeria sealanderi n. sp. were subspherical to ellipsoidal, 16.7 x 14.4 (15-18 x 13-16) microm, with a bilayered wall, externally lightly pitted, internally smooth, and with a shape index of 1.2. A micropyle was absent, but the oocyst residuum and polar granule were present. Oocyst residuum consisted of a single, membrane-bound homogenous granule. Sporocysts were ovoidal, 8.9 x 5.7 (8-10 x 5-6) microm, with a shape index of 1.6; Stieda and sub-Stieda bodies were present. The sporocyst residuum consisted of 10, to several dozen, homogeneous granules of various sizes loosely clustered among the sporozoites, which were elongate and without obvious refractile bodies and nucleus. This is the first time any coccidian has been reported from this host and the first instance of a bat coccidian reported from North Carolina. PMID:20050004

McAllister, Chris T; Upton, Steve J

2009-08-01

398

A new species of Caryospora (Apicomplexa: Eimeriidae) from the bald eagle, Haliaeetus leucocephalus (Accipitriformes: Accipitridae), from Kansas.  

PubMed

Between March 1989 and February 1994, 4 bald eagles ( Haliaeetus leucocephalus ) from various localities in Kansas were examined for coccidia. One (25%) of the bald eagles was found to be passing an undescribed species of Caryospora in its feces. Oocysts of Caryospora hanebrinki n. sp. are ellipsoidal to ovoidal with a bilayered wall and measure 48.1 × 42.1 ?m with a shape index of 1.2. A micropyle, oocyst residuum, and polar granule were absent. Sporocysts are spheroidal, 24.8 ?m wide. Stieda, substieda, and parastieda bodies were absent; a spheroidal sporocyst residuum is present; it measures 17.5 ?m and is composed of many intact homogenous globules with a few dispersed in a loose spiral around the sporocysts. This is the first caryosporan documented from the bald eagle and is the largest known Caryospora from raptors. PMID:22992168

McAllister, Chris T; Duszynski, Donald W; McKown, Richard D

2013-04-01

399

Identification of a Divergent Environmental DNA Sequence Clade Using the Phylogeny of Gregarine Parasites (Apicomplexa) from Crustacean Hosts  

PubMed Central

Background Environmental SSU rDNA surveys have significantly improved our understanding of microeukaryotic diversity. Many of the sequences acquired using this approach are closely related to lineages previously characterized at both morphological and molecular levels, making interpretation of these data relatively straightforward. Some sequences, by contrast, appear to be phylogenetic orphans and are sometimes inferred to represent “novel lineages” of unknown cellular identity. Consequently, interpretation of environmental DNA surveys of cellular diversity rely on an adequately comprehensive database of DNA sequences derived from identified species. Several major taxa of microeukaryotes, however, are still very poorly represented in these databases, and this is especially true for diverse groups of single-celled parasites, such as gregarine apicomplexans. Methodology/Principal Findings This study attempts to address this paucity of DNA sequence data by characterizing four different gregarine species, isolated from the intestines of crustaceans, at both morphological and molecular levels: Thiriotia pugettiae sp. n. from the graceful kelp crab (Pugettia gracilis), Cephaloidophora cf. communis from two different species of barnacles (Balanus glandula and B. balanus), Heliospora cf. longissima from two different species of freshwater amphipods (Eulimnogammarus verrucosus and E. vittatus), and Heliospora caprellae comb. n. from a skeleton shrimp (Caprella alaskana). SSU rDNA sequences were acquired from isolates of these gregarine species and added to a global apicomplexan alignment containing all major groups of gregarines characterized so far. Molecular phylogenetic analyses of these data demonstrated that all of the gregarines collected from crustacean hosts formed a very strongly supported clade with 48 previously unidentified environmental DNA sequences. Conclusions/Significance This expanded molecular phylogenetic context enabled us to establish a major clade of intestinal gregarine parasites and infer the cellular identities of several previously unidentified environmental SSU rDNA sequences, including several sequences that have formerly been discussed broadly in the literature as a suspected “novel” lineage of eukaryotes. PMID:21483868

Rueckert, Sonja; Simdyanov, Timur G.; Aleoshin, Vladimir V.; Leander, Brian S.

2011-01-01

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Haemoproteus ilanpapernai n. sp. (Apicomplexa, Haemoproteidae) in Strix seloputo from Singapore: morphological description and reassignment of molecular data  

PubMed Central

Haemoproteus ilanpapernai Karadjian and Landau n. sp. from the Spotted Wood Owl, Strix seloputo, in Singapore is described from material from Ilan Paperna’s collection of slides. The species was previously identified as Haemoproteus syrnii (Mayer, 1910). However, comparisons between the material from Strix seloputo and our own material from Strix aluco, the type host of H. syrnii, revealed morphological and molecular differences. H. ilanpapernai n. sp. differs morphologically from H. syrnii by the much smaller size of the gametocytes, the different position of the mature gametocytes in the erythrocyte (apical, subapical, or lateral in H. ilanpapernai vs. always lateral in H. syrnii), the effect on the erythrocyte nucleus (frequently tilted in H. ilanpapernai but not displaced laterally vs. straight and displaced laterally in H. syrnii) and characters of the pigment (aggregated in the gametocytes of H. ilanpapernai vs. dispersed in H. syrnii). A molecular analysis showed that the two species differ by 2.9% at the cyt b and 3.1% at the COI genes. PMID:24759652

2014-01-01