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Douglas P. Anderson

Publications and source records attributed to Douglas P. Anderson.

10 recordsLinked to original sources
USGS1993

Enhanced immune response and protection rainbow trout to Aeromonas salmonicida bacterin following prior immersion immunostimulants

Bathing rainbow trout for 30 min in immunostimulant solutions before a 2 min bath in Aeromonas salmonicida O antigen bacterin elevated both the nonspecific defence mechanisms and the specific immune response. Levamisole, a known T lymphocyte stimulator in mammals; QAC, a quaternary ammonium compound, and ISK a short-chain polypeptide, heightened the neutrophil oxidative activity as measured by nitroblue tetrazolium assay and increased the phagocytic uptake of glutaraldehyde-fixed sheep red blood cells. The heightened activity of the specific immune response was monitored by counting numbers of plaque-forming cells, and by demonstrating elevated circulatory antibody titres. Protection levels against the virulent pathogen were also increased when the fish were challenged 14 days later. Giving an immunostimulatory bath before the antigen bath is a relatively easy method of increasing efficacy and potency of immunogens for the prevention of diseases in fishes.

Fish and Shellfish Immunology↗
USGS1993

Glucan injection or bath exposure given alone or in combination with a bacterin enhance the non-specific defence mechanisms in rainbow trout (Oncorhynchus mykiss)

Elevations in the non-specific defence mechanisms were noted after trout were injected or bathed in glucan solutions or in solutions containing the glucan combined with a bacterin, Y. ruckeri O-antigen. Periodic non-lethal blood samples showed that neutrophil activity as evaluated by the ability of the cells to stick to glass and produce oxidative radicals as detected by the nitroblue tetrazolium (NBT) assay, rose after treatments within 2 days. Elevated phagocytosis, assessed by increased uptake of glutaraldehyde-treated sheep red blood cells, also confirmed these kinetics. The numbers of circulatory glass-adherent cells from fish given the glucans by injection or bath was twice the level of the sham-treated controls; likewise the phagocytic ratio also was two-fold higher. In following the kinetics of the non-specific defensive responses, the injection of the glucan caused an immediate, slight reduction of NBT staining cells and numbers of leukocytes before the 2–3 day rise; this was not obvious in the fish given the glucan by bath. The glucans could play an important role in the prevention of diseases in fish culture.

Aquaculture↗
USGS1993

An in vitro technique for surveying immunostimulants in fish

In vitro assays were developed to investigate the effects of immunostimulants on leukocytes in spleen sections of rainbow trout ( Oncorhynchus mykiss ). Fish spleens were divided, and individual sections were placed in 10 ml of tissue culture media and 0.1, 1, 10, or 100 μg/ml dilutions of Levamisole, QAC (quaternary ammonium compound), or ISK (a polypeptide). After 4 days of incubation, cell suspensions were prepared to examine the effects of the immunostimulants on neutrophil oxidative activity using the nitroblue tetrazolium (NBT) assay and on phagocytic activity by engulfment of glutaraldehyde-fixed sheep red blood cells. QAC induced a heightened activity in plates receiving 0.1 and 1.0 μg/ml, but suppressed activity at 10 and 100 μg/ml levels. Sections incubated with ISK showed heightened responses at all doses except 100 μg/ml. Levamisole showed heightened responses at all doses in the NBT assay, and at the 1.0 and 10 μg/ml doses in the phagocytic assay.

Aquaculture↗
USGS1992

Immunostimulants, adjuvants, and vaccine carriers in fish: Applications to aquaculture

Use of immunostimulants, adjuvants, and vaccine carriers in fish culture offers a wide range of attractive methods for inducing and building up protection against diseases. Immunostimulants and adjuvants can be administered before, with, or after vaccines to amplify the specific immune response generating elevations of circulating antibody titers and numbers of plaque-forming cells. Special applications of immunostimulants include assisting shower or other regimens to increase topical uptake of vaccines. In addition, immunostimulants may be used alone, inducing elevated activities in the nonspecific defense mechanisms such as increased oxidative activity of neutrophils, augmented engulfment activity of phagocytic cells, or potentiating cytotoxic cells. In cases where disease outbreaks are cyclical and can be predicted, losses may be reduced by elevating the nonspecific defense mechanisms, and the immunostimulants may be used in anticipation of events to prevent losses from diseases. Complete Freund's adjuvant was one of the first immunostimulants used in animals to elevate the specific immune response, and it has also been successfully used in conjunction with injection of fish bacterins. Other adjuvants, immunostimulants, and biological response modifiers that have been used in fisheries research include levamisole, salt baths, and bacterial lipopolysaccharides. Vaccines have been adsorbed to inert particles, such as bentonite on latex beads, to carry the immunogens to maximize in vivo uptake for bath immunization and to facilitate in vitro phagocytosis. Each substance presents special problems in timing and method of administration (injection, immersion, oral—by feed—or flush treatments), dosage adjustments for size and fish species, storage stability, and cost. An additional consideration is that the nonspecific defense mechanisms and immune responses in fish are highly variable among individuals and statistical validation requires appropriate sample numbers and carefully controlled experiments. This article reviews the literature and present concepts of use of immunostimulants, adjuvants, and vaccine carriers in fish. Cautions for use are noted, as some of these potent substances can suppress or alter biological pathways if used inappropriately. Recent research, defining pathways of the action of immunostimulants, adjuvants, and vaccine carriers, helps explain how these substances activate the protective mechanisms in fish. In addition, immunostimulants used alone hold tremendous potential for use in fish farms, hatcheries, and aquaculture facilities to reduce losses from infectious diseases. Research on the immunostimulant, levamisole, and the light oil adjuvants for use in food fish is in progress. Applications for use of these immunostimulants are proposed.

Annual Review of Fish Diseases↗
USGS1991

The role of the diagnostic laboratory in fish disease control

The diagnostic laboratory is becoming increasingly important to the productivity and profitability of hatcheries, fish farms, and aquaculture stations. The basic function of the laboratory personnel is to isolate and identify viral, bacterial, protozoan, and other fish pathogens present in cultured and feral fish stocks. New, rapid and accurate methods for the detection and identification of fish disease agents based on immunological, biochemical, and physiological assays are becoming commonly used. Nearly every North American state or province and many foreign countries have fish health regulations that require inspection of stocks for certain disease agents before the fish are shipped into their areas. Decisions from the diagnostic laboratory on identification, treatment, guaranteed isolation, immunization, and disposal of fish populations affect administrative directives, hatchery placement, and national and international transportation of fish and fish products. This paper reviews concepts and describes the equipment, supplies, biologics, and media needed for the basic diagnostic laboratory. Information management, including training of staff, certification procedures, and quality control are also discussed.

Annual Review of Fish Diseases↗
USGS1991

Responses to in vitro and in vivo immunisations with Aeromonas salmonicida O antigen bacterins in rainbow trout (Oncorhynchus mykiss)

Immunological assays were developed to test for the effects of immunisation with Aeromonas salmonicida O antigen bacterin in rainbow trout ( Oncorhynchus mykiss ) in vitro and in vivo . Trout spleen sections were immunised in vitro by incubation in media containing 100, 10, and 1 μ g ml −1 of the A. salmonicida O antigen. After 10 days at 15°C, the individual sections were minced and cell suspensions assayed for the effects of the bacterin on non-specific and specific immune responses. Assays of the cell suspensions showed that the neutrophil oxidative activity, phagocytic capabilities, numbers of plaque-forming cells (PFC) and circulating antibody titres all increased in proportion to the bacterin dosage. Trout immunised in vivo with 100 μ g by injection and by 100 μ g ml −1 bath with the O antigen, showed similar responses to spleen sections immunised in vitro . The appearance of non-specific PFC against unlabelled sheep red blood cells was highest in spleens immunised in vitro and in the fish immunised by injection; non-specific PFC rarely occurred in O antigen bathed fish and in control fish. The development of these assays may enable biologists to follow the effects on the non-specific defence mechanisms and the specific immune response in cultivated fish populations after, immunisation with A. salmonicida bacterins and thus aid in the development of protective vaccination against furunculosis.

Fish and Shellfish Immunology↗
USGS1972

Virulence and persistence of rough and smooth forms of Aeromonas salmonicida inoculated into coho salmon (Oncorhynchus kisutch)

Virulent isolates of Aeromonas salmonicida showed a majority of smooth colonies, while the attenuated isolates displayed mostly rough colonies. A lesion occurred at the site of inoculation when one of the rough forms was inoculated into yearling coho salmon, but few mortalities were recorded even though the rough forms were readily recovered from both the lesion and the kidney. The fish inoculated with the same dosage of smooth forms all died within 96 hr of inoculation.

Journal of the Fisheries Research Board of Canada↗
USGS1970

Precipitating antibody against Aeromonas salmonicida in serums of inbred albino Rainbow Trout (Salmo gairdneri)

Precipitins in albino rainbow trout serums were demonstrated by gel diffusion after a single parenteral exposure to the soluble antigens of Aeromonas salmonicida . The fraction of the serum containing antibody activity against the presented antigens was shown by immunoelectrophoresis to be in the nonmigrating region. This corresponded to the beta-2 fraction of rabbit serum. An antibody-containing component comparable with rabbit gamma globulin was not detected.

Journal of the Fisheries Research Board of Canada↗