| a sensitive and specific dna probe for the oyster pathogen haplosporidium nelsoni. | haplosporidium nelsoni is a pathogen of the eastern oyster, crassostrea virginica, along the middle atlantic coast of the u.s. genomic dna was extracted from h. nelsoni plasmodia and small subunit (ssu) rdna was amplified by pcr, cloned and sequenced. the sequence of h. nelsoni ssu rdna was aligned with that of another haplosporidian, minchinia teredinis, and with ssu rdna data of c. virginica and various protists in genbank. a 21-base oligonucleotide unique to h. nelsoni, designated msx1347, wa ... | 1995 | 7620459 |
| characterization of the small subunit ribosomal rna gene of the oyster parasite haplosporidium costale. | the small subunit ribosomal rna (ssu rrna) gene of the oyster parasite haplosporidium costale was characterized from spore dna by polymerase chain reaction (pcr) and molecular cloning. sequence analysis showed that identical clones were obtained from separate batches of spore samples. the gene is 1791 nucleotides in size. it has 84.5% sequence similarity to that of a related oyster parasite, haplosporidium nelsoni, 71.8% similarity to that of its oyster host, crassostrea virginica, and 75.4% sim ... | 1995 | 7670599 |
| phylogeny of the haplosporidia (eukaryota: alveolata) based on small subunit ribosomal rna gene sequence. | the phylogenetic position of the phylum haplosporidia was investigated with the complete small subunit rrna gene sequences from 5 species in the phylum: haplosporidium nelsoni and haplosporidium costale, parasites of the eastern oyster crassostrea virginica; haplosporidium louisiana, a parasite of the mudcrab panopeus herbstii; minchinia teredinis, a parasite of shipworms (teredo spp.) and urosporidium crescens, a hyperparasite found in metacercariae of the trematode megalophallus sp. in the blu ... | 1996 | 8691370 |
| detection of cryptosporidium oocysts and giardia cysts in the tissues of eastern oysters (crassostrea virginica) carrying principal oyster infectious diseases. | the potential cross-reactivity of the combined cryptosporidium/giardia direct immunofluorescence antibodies (ifa) of merifluor and hydrofluor-combo tests was examined against tissues containing known developmental stages of 12 pathogens causing the principal infectious diseases in oysters. spores of haplosporidium nelsoni and haplosporidium costale produced positive acid-fast stain (afs) reactions similar in intensity to cryptosporidium parvum oocysts. hexamia nelsoni trophozoites produced posit ... | 1998 | 9794651 |
| detection of bonamia ostreae based on small subunit ribosomal probe. | bonamia ostreae is a protozoan parasite of the flat oyster, ostrea edulis, which has caused significant loss of oysters in europe over the last decade. b. ostreae was purified from infected flat oysters and dna was extracted. the nearly complete small subunit rdna gene of b. ostreae was amplified using universal oligonucleotides and the pcr product was cloned and sequenced. blast research with this sequence revealed similarities to haplosporidium nelsoni, haplosporidium costale, and minchinia te ... | 2000 | 10963400 |
| development of a multiplex pcr for the detection of haplosporidium nelsoni, haplosporidium costale and perkinsus marinus in the eastern oyster (crassostrea virginica, gmelin, 1971). | haplosporidium costale (sso), haplosporidium nelsoni (msx) and perkinsus marinus (dermo) have caused oyster mortality on the north american east coast since the 1950s. currently, the monitoring of oyster populations for these pathogens depends on histopathology for h. nelsoni, h. costale and the ray/mackin assay for p. marinus. in this study we describe the development and optimization of a multiplex polymerase chain reaction (mpcr) for the detection of h. nelsoni, h. costale and p. marinus. in ... | 2001 | 11851382 |
| spore ornamentation of haplosporidium nelsoni and haplosporidium costale (haplosporidia), and incongruence of molecular phylogeny and spore ornamentation in the haplosporidia. | spore ornamentation of haplosporidium nelsoni and haplosporidium costale was determined by scanning electron microscopy. for h. nelsoni, the spore surface was covered with individual ribbons that were tightly bound together and occurred as a single sheet. in some spores, this layer was overlaid with a network of branching fibers, about 0.05 microm in diameter, which often was dislodged from the spore at the aboral pole. for h. costale, ornamentation consisted of a sparse network of branching fib ... | 2006 | 17304810 |
| characterization of actin genes in bonamia ostreae and their application to phylogeny of the haplosporidia. | bonamia ostreae is a protozoan parasite that infects the european flat oyster ostrea edulis, causing systemic infections and resulting in massive mortalities in populations of this valuable bivalve species. in this work, we have characterized b. ostreae actin genes and used their sequences for a phylogenetic analysis. design of different primer sets was necessary to amplify the central coding region of actin genes of b. ostreae. characterization of the sequences and their amplification in differ ... | 2007 | 17672924 |
| detection of minchinia sp., in rock oysters saccostrea cuccullata (born, 1778) using dna probes. | haplosporidian parasites infect various invertebrate hosts including some commercially important shellfish. haplosporidium nelsoni (along with perkinsus marinus) has severely affected eastern oyster production on the eastern seaboard of the united states and flat oyster production in europe has been severely impacted by bonamia ostreae. these parasites are also often present at a very low prevalence and there are a variety of morphologically similar species that can be difficult to differentiate ... | 2008 | 17709114 |
| haplosporidium costale (sporozoa) associated with a disease of virginia oysters. | a new species of haplosporidium is reported as the cause of a previously unrecognized disease of crassostrea virginica (gmelin) on the eastern shore of virginia. the species is characterized by small (3.1 by 2.6 micro) operculate spores without projections. infections are first seen in late winter, and mortality reaches its peak in early june. | 1962 | 17811215 |
| perkinsus marinus in crassostrea gigas in the gulf of california. | to determine the agent responsible for the massive mortalities of the pacific oyster crassostrea gigas in northwest mexico, 30 oysters were sampled after a severe mortality event in 2006 along the sonoran coast. histological analyses revealed the presence of a protozoan and ray's fluid thioglycollate medium (rftm) assays showed the presence of perkinsus sp., identified as p. marinus from the dna sequence of the internal transcribed spacer (its) of the ribosomal rna (rrna) gene complex. pcr analy ... | 2010 | 20481094 |