| enterocytozoon salmonis n. sp.: an intranuclear microsporidium from salmonid fish. | the developmental stages of a recently described microsporidian from the nucleus of hematopoietic cells of salmonid fish were found to be unique among the microsporida. all observed stages, including meronts, sporonts, and spores were in direct contact with the host cell nucleus (principally hematopoietic cells) of chinook salmon (oncorhynchus tshawytscha). there is no parasitophorous vacuole and sporogony does not involve formation of a pansporoblastic membrane as with other members of the subo ... | 1991 | 1880764 |
| comparative development of two microsporidian species: enterocytozoon bieneusi and enterocytozoon salmonis, reported in aids patients and salmonid fish, respectively. | enterocytozoon bieneusi and enterocytozoon salmonis are reported in hiv-infected patients and in salmonid fish, respectively. both species share the early development of the extrusion apparatus of the spores, which is completed prior to fission of the sporogonic syncytium into sporoblasts, and the early synthesis of polar tube constituents, but they differ in other developmental and sporogenetic processes. enterocytozoon bieneusi develops in direct contact with the cytoplasm of epithelial cells ... | 1996 | 8563709 |
| ribosomal dna sequence of nucleospora salmonis hedrick, groff and baxa, 1991 (microsporea:enterocytozoonidae): implications for phylogeny and nomenclature. | rules of zoological nomenclature, morphological data, and ribosomal dna sequence data support the validity of the genus nucleospora, and its placement in the family enterocytozoonidae. although nucleospora exhibits most of the distinguishing morphological characteristics of the family enterocytozoonidae cali and owen, 1990, the distinctively different hosts (fish and humans, respectively) and sites of development (the nuclei of immature blood cells and the cytoplasm of enterocytes) support the p ... | 1997 | 9172833 |
| plasmacytoid leukemia of chinook salmon. | plasmacytoid leukemia is a common disease of seawater pen-reared chinook salmon (oncorhynchus tshawytscha) in british columbia, canada, but has also been detected in wild salmon, in freshwater-reared salmon in united states, and in salmon from netpens in chile. the disease can be transmitted under laboratory conditions, and is associated with a retrovirus, the salmon leukemia virus. however, the proliferating plasmablasts are often infected with the microsporean enterocytozoon salmonis, which ma ... | 1997 | 9209333 |
| efficacy of the fumagillin analog tnp-470 for nucleospora salmonis and loma salmonae infections in chinook salmon oncorhynchus tshawytscha. | oral treatment with fumagillin is effective for controlling various microsporean and myxosporean infections in fish. we tested a synthetic analog of fumagillin, tnp-470 (takeda chemical industries), for its efficacy against 2 microsporean pathogens of salmon: loma salmonae and nucleospora salmonis. chinook salmon oncorhynchus tshawytscha were experimentally infected with either l. salmonae (per os) or n. salmonis (intraperitoneal, i.p., injection) and held in fresh water at 15 degrees c. fish we ... | 1998 | 9789978 |
| small subunit ribosomal dna phylogeny of microsporidia with particular reference to genera that infect fish. | molecular data have proved useful in the study of microsporidia phylogeny. previous studies have shown that there are several important differences between phylogenies based on rrna and morphological data. in the present study, small subunit (ssu) rdna sequences were obtained from 7 different fish-infecting microsporidia from 4 different genera (glugea thélohan, 1891, loma morrison and sprague, 1981, pleistophora gurley, 1893, and spraguea weissenberg, 1976). the lengths of the ssu rdna genes in ... | 2000 | 10701575 |
| occurrence of the microsporidian parasite nucleospora salmonis in four species of salmonids from the massif central of france. | nucleospora salmonis (hedrick, groff et baxa, 1991), an intranuclear microsporidian parasite of marine and freshwater fish, causes diseases mainly in salmonid species. losses have been reported in stocks of salmonid fish reared in the region of auvergne (france). the cause of chronic mortalities in the local host species raised in aquaculture and destined for supplementation of the river system loire-allier was examined. the presence of n. salmonis was confirmed by pcr and histology in salmo sal ... | 2006 | 16696429 |
| validation of a quantitative pcr diagnostic method for detection of the microsporidian ovipleistophora ovariae in the cyprinid fish notemigonus crysoleucas. | microsporidian parasites are easily detected by light microscopy when infections are heavy and spores are present. however, early infections without spores, or light infections with low numbers of spores, are easily missed. this limitation has made it difficult to conduct investigations into microsporidian prevalence and transmission. in this study, we developed a quantitative taqman polymerase chain reaction assay to assess the presence of ovipleistophora ovariae in the tissues of the cyprinid ... | 2007 | 17803107 |
| animal cell cultures in microsporidial research: their general roles and their specific use for fish microsporidia. | the use of animal cell cultures as tools for studying the microsporidia of insects and mammals is briefly reviewed, along with an in depth review of the literature on using fish cell cultures to study the microsporidia of fish. fish cell cultures have been used less often but have had some success. very short-term primary cultures have been used to show how microsporidia spores can modulate the activities of phagocytes. the most successful microsporidia/fish cell culture system has been relative ... | 2009 | 19184249 |
| paranucleospora theridion n. gen., n. sp. (microsporidia, enterocytozoonidae) with a life cycle in the salmon louse (lepeophtheirus salmonis, copepoda) and atlantic salmon (salmo salar). | paranucleospora theridion n. gen, n. sp., infecting both atlantic salmon (salmo salar) and its copepod parasite lepeophtheirus salmonis is described. the microsporidian exhibits nuclei in diplokaryotic arrangement during all known life-cycle stages in salmon, but only in the merogonal stages and early sporogonal stage in salmon lice. all developmental stages of p. theridion are in direct contact with the host cell cytoplasm or nucleoplasm. in salmon, two developmental cycles were observed, produ ... | 2010 | 20070452 |
| Luna stain, an improved selective stain for detection of microsporidian spores in histologic sections. | Microsporidia in histologic sections are most often diagnosed by observing spores in host tissues. Spores are easy to identify if they occur in large aggregates or xenomas when sections are stained with hematoxylin and eosin (H&E). However, individual spores are not frequently detected in host tissues with conventional H&E staining, particularly if spores are scattered within the tissues, areas of inflammation, or small spores in nuclei (i.e. Nucleospora salmonis). Hence, a variety of selective ... | 2011 | 21848126 |
| nucleospora cyclopteri n. sp., an intranuclear microsporidian infecting wild lumpfish, cyclopterus lumpus l., in icelandic waters. | commercial fisheries of lumpfish cyclopterus lumpus have been carried out in iceland for centuries. traditionally the most valuable part is the eggs which are harvested for use as a caviar substitute.previously reported parasitic infections from lumpfish include an undescribed intranuclear microsporidian associated with abnormal kidneys and mortalities in captive lumpfish in canada. during icelandic lumpfish fisheries in spring 2011, extensive enlargements to the kidneys were observed in some fi ... | 2013 | 23445616 |
| comparative evaluation of molecular diagnostic tests for nucleospora salmonis and prevalence in migrating juvenile salmonids from the snake river, usa. | nucleospora salmonis is an intranuclear microsporidian that primarily infects lymphoblast cells and contributes to chronic lymphoblastosis and a leukemia-like condition in a range of salmonid species. the primary goal of this study was to evaluate the prevalence of n. salmonis in out-migrating juvenile hatchery and wild chinook salmon oncorhynchus tshawytscha and steelhead o. mykiss from the snake river in the u.s. pacific northwest. to achieve this goal, we first addressed the following concern ... | 2011 | 21699133 |
| detection of nucleospora salmonis in steelhead trout, oncorhynchus mykiss (walbaum), using quantitative polymerase chain reaction (qpcr). | | 2009 | 19538644 |
| detection of the intranuclear microsporidium nucleospora salmonis in naturally and experimentally exposed chinook salmon oncorhynchus tshawytscha by in situ hybridization. | nucleospora salmonis, an intranuclear microsporidian parasite of salmonid fish, is often difficult to observe in histological sections or wet mount preparations from lightly infected tissues because of its small size and location within the nuclei of lymphoblast-type cells. diagnosis of infections by conventional light microscopy is directly dependent upon distinguishing different stages of the parasite from host cell nuclear material or vacuoles. to assist detection of stages of the parasite in ... | 2007 | 17605006 |
| comparison of small subunit ribosomal rna gene and internal transcribed spacer sequences among isolates of the intranuclear microsporidian nucleospora salmonis. | nucleospora salmonis is an intranuclear microsporidian associated with a proliferative disorder of the lymphoid cells of captive salmonid fish in the northwestern and northeastern regions of north america, in france, and in chile. newer diagnostic approaches have used the polymerase chain reaction (pcr) to detect the parasite in fish tissues. the target sequences for these assays lie in the small subunit ribosomal rna (ssu rrna) gene or internal transcribed spacer (its) as determined from n. sal ... | 2006 | 11140452 |
| molecular detection and phylogenetic placement of a microsporidian from english sole (pleuronectes vetulus) affected by x-cell pseudotumors. | flatfish tissue samples exhibiting x-cell pseudotumors were tested with a number of ribosomal dna (rdna) general primers in polymerase chain reactions (pcrs). microsporidian primers resulted in the amplification of an rdna fragment and molecular phylogenetic analysis indicated that although the organism did not relate closely with any current microsporidian genera, it was most similar to nucleospora salmonis and branched within the enterocytozoonidae. re-examination of the original tissues used ... | 2000 | 10958476 |
| estimation of sensitivity and specificity of diagnostic tests and disease prevalence when the true disease state is unknown. | the performance of a new diagnostic test is frequently evaluated by comparison to a perfect reference test (i.e. a gold standard). in many instances, however, a reference test is less than perfect. in this paper, we review methods for estimation of the accuracy of a diagnostic test when an imperfect reference test with known classification errors is available. furthermore, we focus our presentation on available methods of estimation of test characteristics when the sensitivity and specificity of ... | 2000 | 10802334 |
| effect of the microsporidian enterocytozoon salmonis on the immune response of chinook salmon. | the protozoan parasite enterocytozoon salmonis is an intranuclear microsporidian of salmonid mononuclear leukocytes. experimental infections were initiated in chinook salmon to determine the effects of parasitism on selected host immune functions. the humoral antibody response to dinitrophenylated-keyhole limpet hemocyanin and the in vitro blastogenic responses of isolated mononuclear leukocytes to mitogens (concanavalin a, lipopolysaccharide and phytohemagglutinin-p) were evaluated. the humoral ... | 1995 | 8578694 |
| in vitro characteristics of the microsporidian: enterocytozoon salmonis. | enterocytozoon salmonis, as intranuclear microsporidian of salmonid fish, was propagated in vitro using chinook salmon mononuclear leukocytes. characteristic morphology and infectivity of the cultured parasites were evaluated to determine the effect of in vitro maintenance and passage on the parasites. cultured parasites developed through several stages from meronts to infectious spores. parasites obtained from in vitro passages tested up to the 17th subculture, retained their morphological char ... | 2006 | 7620465 |
| experimental horizontal transmission of enterocytozoon salmonis to chinook salmon, oncorhynchus tshawytscha. | enterocytozoon salmonis was transmitted to chinook salmon oncorhynchus tshawytscha by feeding tissues infected with the parasite and by cohabitation of noninfected fish with experimentally infected fish. affected fish (dead and survivors) in both transmission trials had gross and microscopic signs of the disease and merogonic and sporogonic stages of the parasite. there were no morbidities or mortalities, or evidence of the parasite among control fish in either study. results suggest that the pa ... | 2006 | 1453359 |