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Recombinant vaccines against infectious hematopoietic necrosis virus : bacterial systems for vaccine production and deliverySimon, Benjamin E. 09 October 2001 (has links)
Several systems were examined for the production and delivery of recombinant
vaccines for fish. C. crescentus was employed to produce a fragment of the IHNV
glycoprotein. When administered by injection to 0.5 gram rainbow trout (Oncorhynchus
mykiss), one of the fusion proteins (184 amino acids of the IHNV glycoprotein fused to
242 amino acids of the C-terminus of the Caulobacter crescentus) protected the fish
against lethal challenge with IHNV. Attenuated strains of Yersinia ruckeri were
generated using allelic exchange mutagenesis. These strains were characterized in terms
of in vitro growth characteristics and invasiveness. Attenuated E. coli and Y. ruckeri
were exploited to deliver plasmid DNA to fish cells in vitro; attenuated Y. ruckeri
bacteria were examined in vivo as bivalent vaccine delivery vehicles, either through the
expression of a fragment of the IHNV glycoprotein or by carrying a plasmid DNA
vaccine encoding the complete IHNV glycoprotein. A cell wall deficient strain
(11.29��dap) protected rainbow trout against lethal challenge with pathogenic Y. ruckeri.
Gene transfer to fish was not detected by luciferase reporter gene assays. No clear
protection from IHNV challenge was observed. / Graduation date: 2002
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Genetic diversity, evolution, and fitness of infectious hematopoietic necrosis virus within an endemic focus in rainbow trout aquaculture /Troyer, Ryan M. January 2002 (has links)
Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 130-160).
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Biological and mathematical modeling of dynamics of furunculosis in chinook salmon (Oncorhynchus tshawytscha) and infectious hematopoietic necrosis (IHN) in rainbow trout (Oncorhynchus mykiss)Ogut, Hamdi 08 January 2001 (has links)
A series of experiments with Aeromonas salmonicida and infectious
hematopoietic necrosis virus (IHNV) were carried out to determine dynamics of the
spread of infection in chinook salmon (1.2-1.98g) and rainbow trout (1.2-3.1g). It was
found in experiments with A. salmonicida that fish infected by bath immersion became
infectious at 4 days postexposure (dpe), one day prior to dying from furunculosis. In
cohabitation experiments with a single infected fish donor, an average of 75% disease
specific mortality was obtained. There was suggestive evidence that there is a positive
relationship between holding volumes and furunculosis prevalence in cohabitation
experiments with single donor fish. Median day to infection was inversely correlated
with density. The threshold density at density of 1.97 fish/L was approximately 30 times
less than the density of 0.08 fish/L, 13.33 and 320 fish respectively. Reproductive ratio
(R₀) and transmission coefficient (β) in the furunculosis epizootic were 3.23 and 0.021
(individuals*day)⁻¹ respectively. The mortality rate (α) of infected animals was 28.7%
per day. The models constructed successfully mirrored the results of laboratory
experiments. Data produced by simulation of the models were significantly associated
with the data obtained from laboratory experiments for susceptible (S) class and also for
infected class.
In similar experiments carried out with IHNV, it was found that donor fish
became infectious 3 dpe. The virus levels in donor fish and prevalence levels were also
highly associated. Smaller volumes of that led to higher prevalence levels than observed
in bigger volumes with 60 or 30 fish in each. A single donor fish was able to transfer
virus to recipient fish. However, unlike the A. salmonicida experiment, transmission was
insufficient to initiate a full-scale infectious hematopoietic (IHN) epizootic. Estimated
parameters for dynamics of infection were approximately half of the values for A.
salmonicida (R₀=2.57,β=0.008 (individuals*day)⁻¹ and α=0.15). The models
constructed for IHNV spread were used to simulate the results of density experiment.
However, it was not possible to test the association between susceptible and infected
classes due to inadequate number of infected fish. / Graduation date: 2001
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Novel formulation : development of oral microparticulate non-viral DNA vaccine delivery system against infectious hematopoetic necrosis virus (IHNV) in Rainbow Trout, statistical design in matrix tablets formulationTantituvanont, Angkana 07 May 2003 (has links)
This dissertation describes two different projects. The first is the development
of an oral DNA vaccine delivery system for fish. A novel oral DNA vaccine delivery
system was developed for Rainbow Trout by combining non-viral vectors
(polycationic liposomes or polycationic polymer) to facilitate the DNA vaccine's
uptake by cell membranes along with enteric-coated protection of the DNA embedded
in microparticles to prevent DNA degradation in the gastrointestinal tract. Spray
drying and spray coating bead techniques were employed in the preparation of the
DNA vaccine microparticles. The spray drying technique allowed production of
spherical shape enteric-coated microparticles with a particle size range of 0.18 to 20
��m. Larger particle sizes of 40-50 mesh were obtained from the spray-coated bead
technique. The resultant DNA vaccine microparticles were granulated with regular
fish feed and given to fish to investigate the efficacy of the delivery system in
providing protection against IHNV, and to demonstrate the ease of administration in
fish. An in vivo fish trial experiment showed improvement in fish survival rate when
fish were immunized with larger particle size DNA vaccine microparticles. Further
research to find effective vector carriers for the DNA vaccine delivery system and to
seek modifications of the delivery system that will still prevent the denaturation of
plasmid DNA that will also facilitate membrane uptake of the DNA vaccine is needed
in order to develop a safe, effective, and commercially viable vaccine to control the
outbreak of IHNV.
The second project of the dissertation is prediction of in vitro drug release
profiles from a novel matrix tablet spray-coated with a barrier membrane using
mathematical and statistical models. Tablets were prepared by direct compression
followed by spray coating. The relationship of the amount of hydrophilic materials in
the core tablets and barrier thickness on drug release mechanism was investigated
using factorial design and regression analysis. Drug release characteristics were
influenced and can be controlled by modifying the amount of hydrophilic materials in
the core tablet and the barrier thickness. Mathematical equation generated from
regression analysis of n-value, lag time, and percent drug release as a function of the
amount of hydrophilic material and the amount of coating material applied can now be
used as a tool for predicting and optimizing in vitro drug release from matrix tablets
spray-coated with a barrier membrane. / Graduation date: 2003
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