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Full-Text Articles in Life Sciences

Parasitism In Species Of Bathymodiolus (Bivalvia : Mytilidae) Mussels From Deep-Sea Seep And Hydrothermal Vents, Me Ward, Jd Shields, Cl Van Dover Nov 2004

Parasitism In Species Of Bathymodiolus (Bivalvia : Mytilidae) Mussels From Deep-Sea Seep And Hydrothermal Vents, Me Ward, Jd Shields, Cl Van Dover

VIMS Articles

Bivalve species, especially mussels, are biomass dominants in many deep-sea chemosynthetic ecosystems. As in shallow-water environments, parasites are likely to be important factors in the population dynamics of bivalve communities in chemosynthetic ecosystems, but there has been little study of parasitism in deep-sea seep or vent molluscs. In this study, Parasite types, diversity, prevalence, infection density and non-infectious indicators of stress or disease as related to host age, reproductive condition, and endosymbiont density were assessed in mussels (Bathmodiolus heckerae) from 2 seep sites and mussels (B. puteoserpentis) from 2 vent sites. We identified 10 microbial or parasitic agents in histological ...


Real-Time Pcr For Detection And Quantification Of The Protistan Parasite Perkinsus Marinus In Environmental Waters, C Audemard, Ks Reece, Em Burreson Nov 2004

Real-Time Pcr For Detection And Quantification Of The Protistan Parasite Perkinsus Marinus In Environmental Waters, C Audemard, Ks Reece, Em Burreson

VIMS Articles

The protistan parasite Perkinsus marinus is a severe pathogen of the oyster Crassostrea virginica along the east coast of the United States. Very few data have been collected, however, on the abundance of the parasite in environmental waters, limiting our understanding of P. marinus transmission dynamics. Real-time PCR assays with SybrGreen I as a label for detection were developed in this study for quantification of P. marinus in environmental waters with P. marinus species-specific primers and of Perkinsus spp. with Perkinsus genus-specific primers. Detection of DNA concentrations as low as the equivalent of 3.3 x 10(-2) cell per ...


Ultrastructure Of Mycobacterium Marinum Granuloma In Striped Bass Morone Saxatilis, Dt Gauthier, Wk Vogelbein, Ca Ottinger Oct 2004

Ultrastructure Of Mycobacterium Marinum Granuloma In Striped Bass Morone Saxatilis, Dt Gauthier, Wk Vogelbein, Ca Ottinger

VIMS Articles

An emerging epizootic of mycobacteriosis currently threatens striped bass Morone saxatilis populations in Chesapeake Bay, USA. Several species of mycobacteria, including Mycobacterium marinum, species resembling AT. avium, All. gordonae, M. peregrinum, M. scrofulaceum and M. terrae, and the new species M. shottsii have been isolated from diseased and healthy bass. In this study, we describe the ultrastructure of developing M. marinum granulomas in experimentally infected bass over a period of 45 wk. The primary host response to injected mycobacteria was formation of large macrophage aggregations containing phagocytosed bacilli. AT marinum were always contained within phagosomes. Close association of lysosomes with ...


Infection Dynamics Of Marteilia Refringens In Flat Oyster Ostrea Edulis And Copepod Paracartia Grani In A Claire Pond Of Marennes-Oleron Bay, C Audemard, Mc Sajus, Et Al Oct 2004

Infection Dynamics Of Marteilia Refringens In Flat Oyster Ostrea Edulis And Copepod Paracartia Grani In A Claire Pond Of Marennes-Oleron Bay, C Audemard, Mc Sajus, Et Al

VIMS Articles

The protozoan parasite Marteilia refringens has been partly responsible for the severe decrease in the production of the European flat oyster Ostrea edulis Linnaeus in France since the 1970s. The calanoid copepod Paracartia grani Sars was recently found to be a host for M refringens in French shallow-water oyster ponds ('claires'). This study reconsidered M refringens transmission dynamics in the light of this finding, taking into account not only oyster infection dynamics and environmental factors but also data concerning the copepod host. P. grani population dynamics in the claire under study revealed that this species is the dominant planktonic copepod ...


Isolation And Characterization Of Mycobacteria From Striped Bass Morone Saxatilis From The Chesapeake Bay, Mw Rhodes, H Kator, I Kaattari, D Gautier, W Vogelbein, Ca Ottinger Sep 2004

Isolation And Characterization Of Mycobacteria From Striped Bass Morone Saxatilis From The Chesapeake Bay, Mw Rhodes, H Kator, I Kaattari, D Gautier, W Vogelbein, Ca Ottinger

VIMS Articles

Mycobacteriosis in striped bass Morone saxatilis of Chesapeake Bay, USA, was first diagnosed in 1997 based on the presence of granulomatous inflammation and acid-fast bacteria in skin and spleen. To confirm histopathology, bacteriological detection and identification of mycobacteria were begun using splenic tissue from fish with and without skin ulcerations. On the basis of initial studies using a variety of selective and nonselective media, decontamination, homogenization and incubation conditions, a simple and quantitative recovery method using aseptic necropsy of splenic tissue was developed. Optimal recovery was obtained by spread-plating homogenates on Middlebrook 7H10 agar with incubation for 3 mo at ...


Microsatellite Marker Development And Analysis In The Eastern Oyster (Crassostrea Virginica): Confirmation Of Null Alleles And Non-Mendelian Segregation Ratios, Ks Reece, Wl Ribeiro, Pm Gaffney, Rb Carnegie, Sk Allen Jul 2004

Microsatellite Marker Development And Analysis In The Eastern Oyster (Crassostrea Virginica): Confirmation Of Null Alleles And Non-Mendelian Segregation Ratios, Ks Reece, Wl Ribeiro, Pm Gaffney, Rb Carnegie, Sk Allen

VIMS Articles

Eighteen microsatellite markers were developed for the Crassostrea virginica nuclear genome, including di-, tri-, and tetranucleotide microsatellite repeat regions that included perfect, imperfect, and compound repeat sequences. A reference panel with DNA from the parents and four progeny of 10 full-sib families was used for a preliminary confirmation of polymorphism at these loci and indications of null alleles. Null alleles were discovered at three loci; in two instances, primer redesign enabled their amplification. Two to five representative alleles from each locus were sequenced to ensure that the targeted loci were amplifying. The sequence analysis revealed not only variation in the ...


A New Pathogenic Virus In The Caribbean Spiny Lobster Panulirus Argus From The Florida Keys, Jd Shields, Dc Behringer May 2004

A New Pathogenic Virus In The Caribbean Spiny Lobster Panulirus Argus From The Florida Keys, Jd Shields, Dc Behringer

VIMS Articles

A pathogenic virus was diagnosed from juvenile Caribbean spiny lobsters Panulirus argus from the Florida Keys. Moribund lobsters had characteristically milky hemolymph that did not clot. Altered hyalinocytes and semigranulocytes, but not granulocytes, were observed with light microscopy. Infected hemocytes had emarginated, condensed chromatin, hypertrophied nuclei and faint eosinophilic Cowdry-type-A inclusions. In some cases, infected cells were observed in soft connective tissues. With electron microscopy, unenveloped, nonoccluded, icosahedral virions (182 +/- 9 nm SD) were diffusely spread around the inner periphery of the nuclear envelope. Virions also occurred in loose aggregates in the cytoplasm or were free in the hemolymph. Assembly ...


Mycobacterium-Inducible Nramp In Striped Bass (Morone Saxatilis), Erin J. Burge, David T. Gauthier, Christopher A. Ottinger, Peter A. Van Veld Mar 2004

Mycobacterium-Inducible Nramp In Striped Bass (Morone Saxatilis), Erin J. Burge, David T. Gauthier, Christopher A. Ottinger, Peter A. Van Veld

VIMS Articles

In mammals, the natural resistance-associated macrophage protein 1 gene, Nramp1, plays a major role in resistance to mycobacterial infections. Chesapeake Bay striped bass (Morone saxatilis) is currently experiencing an epizootic of mycobacteriosis that threatens the health of this ecologically and economically important species. In the present study, we characterized an Nramp gene in this species and obtained evidence that there is induction following Mycobacterium exposure. The striped bass Nramp gene (MsNramp) and a 554-amino-acid sequence contain all the signal features of the Nramp family, including a topology of 12 transmembrane domains (TM), the transport protein-specific binding-protein-dependent transport system inner membrane ...


Perkinsus Mediterraneus N. Sp., A Protistan Parasite Of The European Flat Oyster Ostrea Edulis From The Balearic Islands, Mediterranean Sea, Sm Casas, A Grau, Ks Reece, Et Al Mar 2004

Perkinsus Mediterraneus N. Sp., A Protistan Parasite Of The European Flat Oyster Ostrea Edulis From The Balearic Islands, Mediterranean Sea, Sm Casas, A Grau, Ks Reece, Et Al

VIMS Articles

A new species, Perkinsus mediterraneus, a protistan parasite of the European oyster Ostrea edulis (L.), farmed along the coast of the Balearic Islands, Mediterranean Sea, is described. Morphological examinations with light and transmission electron microscopy, DNA sequence-analysis and enlargement in Ray's fluid thioglycollate medium (RFTM) confirmed that this parasite belongs to the genus Perkinsus. Specific morphological and genetic characteristics indicated that it should be considered a new species in the genus, Sequencing of the small subunit ribosomal (ssu rRNA) gene confirmed that the parasite belongs to the genus Perkinsus, and sequences of the internal transcribed spacer (ITS) were distinct ...


Plasmablast And Plasma Cell Production And Distribution In Trout Immune Tissues, E S. Bromage, I M. Kaattari, P Zwollo, S L. Kaattari Jan 2004

Plasmablast And Plasma Cell Production And Distribution In Trout Immune Tissues, E S. Bromage, I M. Kaattari, P Zwollo, S L. Kaattari

VIMS Articles

These studies describe the in vitro and ex vivo generation of plasmablasts and plasma cells in trout (Oncorhynchus mykiss) peripheral blood and splenic and anterior kidney tissues. Cells were derived either from naive trout and cultured with the polyclonal activator, Escherichia coli LPS, or from trout that had been immunized with trinitrophenyl-keyhole limpet hemocyanin. Hydroxyurea was used to resolve populations of replicating (plasmablast) and nonreplicating (plasma cell) Ab-secreting cells (ASC). Complete inhibition of Ig secretion was only observed within the PBL. Both anterior kidney and splenic lymphocytes possessed a subset of ASCs that were hydroxyurea resistant. Thus, in vitro production ...


Supplementation Of Perkinsus Marinus Cultures With Host Plasma Or Tissue Homogenate Enhances Their Infectivity, Cg Earnhart, Ma Vogelbein, Gd Brown, Ks Reece, Sl Kaattari Jan 2004

Supplementation Of Perkinsus Marinus Cultures With Host Plasma Or Tissue Homogenate Enhances Their Infectivity, Cg Earnhart, Ma Vogelbein, Gd Brown, Ks Reece, Sl Kaattari

VIMS Articles

The protozoan oyster parasite Perkinsus marinas can be cultured in vitro in a variety of media; however, this has been associated with a rapid attenuation of infectivity. Supplementation of defined media with products of P. marinus-susceptible (Crassostrea virginica) and -tolerant (Crassostrea gigas, Crassostrea ariakensis) oysters alters proliferation and protease expression profiles and induces differentiation into morphological forms typically seen in vivo. It was not known if attenuation could be reversed by host extract supplementation. To investigate correlations among these changes as well as their association with infectivity, the effects of medium supplementation with tissue homogenates from both susceptible and tolerant ...


A Review Of Recent Information On The Haplosporidia, With Special Reference To Haplosporidium Nelsoni (Msx Disease), E M. Burreson, S E. Ford Jan 2004

A Review Of Recent Information On The Haplosporidia, With Special Reference To Haplosporidium Nelsoni (Msx Disease), E M. Burreson, S E. Ford

VIMS Articles

The current status of the Haplosporidia is reviewed as well as recent information on Haplosporidium nelsoni, the causative agent of MSX disease in oysters. Recent molecular phylogenetic analyses with greatly increased taxon sampling support monophyly of the Haplosporidia and hypothesize placement of the group as sister taxon to the phylum Cercozoa. Oyster pathogens in the genus Bonamia should be considered haplosporidians based on molecular sequence data. Thus, the group contains 4 genera: Uropsoridium, Haplosporidium, Bonamia and Minchinia. Molecular phylogenetic analyses support monophyly of Urosporidium, Bonamia and Minchinia, but Haplosporidium forms a paraphyletic clade. Reports of haplosporidia worldwide are reviewed. Molecular ...


Perkinsosis In Molluscs: A Review, Antonio Villalba, Kimberley S. Reece, M. Camino Ordas, Sandra M. Casas, Antonio Figueras Jan 2004

Perkinsosis In Molluscs: A Review, Antonio Villalba, Kimberley S. Reece, M. Camino Ordas, Sandra M. Casas, Antonio Figueras

VIMS Articles

The genus Perkinsus includes protistan parasites infecting marine molluscs throughout the world, some of which are associated with mass mortalities. Life cycle involves vegetative proliferation within the host, by which a cell named trophozoite undergoes successive bipartitioning. Other stages have been observed in vitro or in vivo, depending on the species: hypnospore, zoosporangium and zoospore. Molecular taxonomy supports a close affinity between dinoflagellates and Perkinsus spp. Six species of Perkinsus are currently considered valid: P. marinus, P. olseni, P. qugwadi, P. chesapeaki, P. andrewsi and P. mediterraneus. Histology and, above all, incubation of host tissues in Ray’s fluid thioglycollate ...


Microcell Parasites Of Oysters: Recent Insights And Future Trends, Ryan B. Carnegie, Nathalie Cochennec-Laureau Jan 2004

Microcell Parasites Of Oysters: Recent Insights And Future Trends, Ryan B. Carnegie, Nathalie Cochennec-Laureau

VIMS Articles

Our understanding of the microcell oyster parasites of the genera Bonamia and Mikrocwos has expanded 111 recent years with the application of ultrastru ctural and espec ially molecular biological research approaches. Molecular phylogenetic analyses of SSU rRNA genes have united three species, Bonamia ostreae, Bonamia exitiosa, and Mikrocytos (now Bonamia) roughleyi, in a microcell clade within the Haplosporidia, supporting both early and recent ultrastructural observations. Ult rastructural and molecular phylogenetic ev idence has emerged that Mikrocytos mackini, on the other hand, is a unique proti st with unusual adaptations for a parasitic existence. DNA probes and polymerase chain reaction (PCR ...


Perkiasus Sp Infection Risk For Manila Clams, Venerupis Philippinarum (A. Adams And Reeve, 1850) On The Pacific Coast Of North And Central America, Ra Elston, Cf Dungan, Tr Meyers, Ks Reece Jan 2004

Perkiasus Sp Infection Risk For Manila Clams, Venerupis Philippinarum (A. Adams And Reeve, 1850) On The Pacific Coast Of North And Central America, Ra Elston, Cf Dungan, Tr Meyers, Ks Reece

VIMS Articles

Manila clams (Venerupis philippinarum, A. Adams and Reeve 1850) are an important aquaculture species on the west coast of North America and are also cultured in Europe, Asia, and other locations. Clams cultured on the west coast of North America are free of Perkinsus sp. infections, while clams from certain Asian and European sources are infected. Infection in Korean Manila clams is reportedly associated with high morbidity and mortality. We evaluated the health status of readily accessible Manila clam juveniles from Korea that were proposed for importation into Mexican waters where they would increase in size, and then be shipped ...