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Biomedical subjects

J L Fryer

Publications and source records attributed to J L Fryer.

At least 37 records · Page 2Linked to original sources
PubMed1988

Molecular filtration for recovery of waterborne viruses of fish.

The effectiveness of tangential flow filtration (TFF) for the recovery of infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV) from large volumes of water was evaluated. In laboratory studies, virus recovery from IHNV-seeded water following concentration by TFF was approximately 13%. However, the addition of 0.1 and 1% fetal bovine serum to deionized water stabilized the virus, increasing virus recoveries to 95%. The addition of 0.03 and 0.3% beef extract resulted in IHNV recoveries of 80 and 61%, respectively. Similar results were obtained with IPNV-seeded water. Field studies using the TFF procedure were conducted with water from areas where IHNV is endemic. IHNV was detected in effluent from an adult steelhead trout (Salmo gairdneri) holding pond at an estimated concentration of 1 PFU/5 ml of water. It was also detected at levels of 1 PFU/50 ml in water from a 2-m-diameter circular tank containing IHNV-infected steelhead trout fry. IHNV isolated in samples taken from the Metolius River was detected by TFF at estimated levels of 1 PFU/3 liters.

Animals↗
PubMed1988

Isolation of Aeromonas salmonicida from masu salmon in the Republic of Korea.

The isolation and identification of the Gram-negative fish pathogen, Aeromonas salmonicida salmonicida, from masu salmon (Oncorhynchus masou) at the Yang Yang Salmon Hatchery in the Republic of Korea is described. The bacterium possessed certain characteristics in common with isolates from fish in Japan. It is an important cause of mortality among cultured salmonids in the Republic of Korea. This is the first report of this fish pathogen from the Asian mainland.

Aeromonas↗
PubMed1987

Morphological and biochemical properties of four members of a novel group of reoviruses isolated from aquatic animals.

The morphological, biochemical and growth characteristics of four members of the Reoviridae, three from the fish hosts, golden shiner (Notemigonus crysoleucas), chum salmon (Oncorhynchus keta) and channel catfish (Ictalurus punctatus) and one from American oyster (Crassostrea virginica), were compared. Electron microscopy of negatively stained virions revealed icosahedral particles approximately 75 nm in diameter composed of a double capsid. Complete particles had buoyant densities in CsCl of 1.34 to 1.36 g/ml. The viruses replicated well in several fish cell lines, forming plaque-like syncytia in monolayer cultures. Each virus could be distinguished by the range of cell lines supporting its growth. Polyacrylamide gel electrophoresis showed that the genome of each virus was composed of 11 segments of dsRNA distributed among three size classes. There were three large, three medium and five small segments in each genome and each isolate had a unique electropherotype. The segments ranged from 2.5 X 10(6) to 0.31 X 10(6) mol. wt. with a total genome of approximately 15 X 10(6) mol. wt. Analysis by SDS-PAGE revealed that each virus had five major structural proteins. There were two large polypeptides of approximately 135,000 and 125,000 mol. wt., one medium size polypeptide of 70,000 mol. wt. and two small polypeptides of 45,000 and 34,000 mol. wt. Of the major structural proteins, those of approximately 70,000 and 34,000 mol. wt. were consistently present in the highest concentrations. Minor virion proteins were detected but were not characterized. These four viruses, isolated from aquatic animals, were unlike viruses of the six established genera of the Reoviridae.

Animals↗
PubMed1987

Serological evidence of California serogroup virus activity in Oregon.

We wished to demonstrate evidence of the presence of California serogroup viruses in Oregon and to test for the presence of certain other arboviruses in large ungulates. Blood samples from black-tailed deer (Odocoileus hemionus columbianus), mule deer (O. hemionus hemionus), and Roosevelt elk (Cervus elaphus roosevelti) from nine counties in Oregon were tested by serum-dilution plaque reduction neutralization for antibody to California serogroup viruses, including snowshoe hare, California encephalitis, and Jamestown Canyon, as well as to Cache Valley (Bunyamwera serogroup) and Klamath, an ungrouped rhabdovirus. Of 132 samples tested, 60 (46%) were found to be seropositive at a dilution of greater than or equal to 1:10 for at least one of the five different arboviruses. Forty (30%) samples contained antibody to more than one arbovirus, and 15 samples (11%) contained antibody to all five. Of these 15, 14 were from 75 black-tailed deer sera collected in Lincoln County, Oregon. Seropositivity rates for black-tailed deer ranged from 23% to 35%, with all five arboviruses represented. Positive reactions for all five arboviruses were represented among mule deer sera at rates from 5% to 29%. Elk sera were found to be positive for four of the viruses (none for Klamath virus). Although Cache Valley and Klamath viruses have been reported from Oregon, these data represent the first evidence of a California serogroup virus in the state.

Animals↗
PubMed1984

Fish cell lines: establishment and characterization of nine cell lines from salmonids.

Nine permanent cell lines have been established from five species of salmonids native to America's Pacific Northwest. With the exception of a hepatoma from an adult trout, the lines were derived from normal tissues of embryonic or juvenile fish. Cells were routinely grown in Eagle's minimum essential medium with 10% fetal bovine serum. Optimum growth temperatures for these lines ranged from 21 to 24 degrees C. All survived storage for at least 1 yr at -65 degrees C and at least 5 yr in liquid nitrogen. Six of the lines were demonstrably free of any microbial contamination but mycoplasmas were found in three. Eight of the lines were heteroploid. The morphology of only one was fibroblastic. All the lines effectively replicated one or more of the common salmonid viruses. Isozyme patterns were consistent with those of the species of origin. These cell lines have significant application in fish virology.

Animals↗
PubMed1983

Biochemical characterization of eel virus european.

The polypeptide and RNA compositions of purified virions of eel virus European were compared to those of three strains (VR-299, SP and AB) of infectious pancreatic necrosis virus (IPNV) isolated from trout. All three IPNV strains could be distinguished by the relative mobilities of either the virion polypeptides or the double-stranded RNA genome segments. The eel virus had a similar polypeptide profile to strain AB IPNV but differences between the two viruses in the migration of genome segments indicated each was unique.

Animals↗
PubMed1982

Isolation and characterization of Edwardsiella tarda from fall chinook salmon (Oncorhynchus tshawytscha).

A new bacterial pathogen of chinook salmon (oncorhynchus tshawytscha) was isolated from fish in Oregon's Rogue River. The bacteria are biochemically and serologically related to strains of Edwardsiella tarda. Initially isolated from chinook salmon, the bacteria were also pathogenic for steelhead and rainbow trout (Salmo gairdneri), and channel catfish (Ictalurus punctatus). The 50% lethal doses for chinook salmon, steelhead trout, and channel catfish injected intraperitoneally and maintained in 18 degrees C water were 4.1 x 10(6), 5.6 x 10(6), and 4.0 x 10(5) respectively. When chinook salmon and rainbow trout were injected intraperitoneally and held in 12 degrees C water, the mean lethal doses were 6.4 x 10(7) and 1.7 x 10(6), respectively. The invasiveness of the organism was low in steelhead trout exposed to the bacteria by the waterborne route. The optimum growth temperature of the bacteria in brain heart infusion broth was approximately 35 degrees C. The guanine plus cytosine content of DNA obtained from E. tarda isolated from salmon was 59 mol%.

Animals↗
PubMed1980

The viral diseases of fish: a review through 1978. Part 1: Diseases of proven viral etiology.

In this review, a survey is made of the published literature on the viral diseases of fish available up to and including the year 1978. It is divided into two main sections. Part 1 describes 11 diseases where a virus has been isolated and proven to be the causative agent. Part 2 discusses 16 diseases where there is reason to suspect viral etiology because of evidence deriving from electron microscopy or transmission experiments with bacteria-free filtrates of homogenates of diseased tissue, but where final proof of a causative relationship is lacking. The review attempts to provide the most significant information on the disease process itself, in most cases including external signs, fish species susceptible, pathology, geographic distribution, existence of carriers, methods of transmission, and control. It also gives the most recent and significant data concerning the nature of the causative virus, including its cultural, biological, and physicochemical properties, where such information is available.

Anguilla↗
PubMed1979

Increased susceptibility of rainbow trout to infectious hematopoietic necrosis virus after exposure to copper.

Exposure of rainbow trout to sublethal levels of copper in water increased their susceptibility to infectious hematopoietic necrosis virus. In most instances, the percent mortality was twice as great in the stressed groups compared with those groups which were not stressed but received the same virus dose. Although the level of copper in the water influenced the mortality rates, the length of exposure did not prove to be critical, as similar results were obtained after 1, 3, 5, 7, or 9 days of exposure. When different virus challenges were employed, the percent mortalities were again greater in the stressed fish at all virus doses tested, and at one dose level mortalities were noted in the stressed group but not in the untreated group.

Journal Article↗
PubMed1974

Characterization of anti-Aeromonas salmonicida antibodies from coho salmon.

Coho salmon (Oncorhynchus kisutch) anti-Aeromonas salmonicida agglutinins were excluded from Sephadex G-200 and their activity was lost after partial reduction and alkylation followed by exposure to 2 M urea. Immunoelectrophoretic analysis of coho antiserum revealed anodic and cathodic populations of immunoglobulin (Ig), and the anti-A. salmonicida antibodies present 12 weeks after parenteral immunization were primarily anodic Ig. Antibodies were specifically purified by dissociation of A. salmonicida cell wall agglutinates with 15% NaCl. The purified Ig was a 17S macroglobulin, and electron microscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that it was composed of four IgM-like subunits. The minimum coho antibody concentration required for visible agglutination of A. salmonicida cells was approximately 0.006 mug of Ig nitrogen/ml.

Aeromonas↗