Record Details
Field | Value |
---|---|
Title | Pathogenic, antigenic, and immunogenic properties of Aeromonas salmonicida studied in juvenile coho salmon (Oncorhynchus kisutch) |
Names |
Udey, Lanny R.
(creator) Fryer, J. L. (advisor) |
Date Issued | 1977-07-20 (iso8601) |
Note | Graduation date: 1978 |
Abstract | An additional layer, exterior to the outer membrane cellwall layer, was found on Aeromonas salmonicida cells from aggregating strains. Nonaggregating strains were found to lack this layer. The nonaggregating strains were all avirulent (LD₅₀ greater than 1 X 10 ⁸ CFU/fish) while the majority of the aggregating strains were virulent (LD ₅₀ less than 1 X 10 ⁴ CFU/fish). Other, yet undetermined virulence factors may also be required for strains to be highly virulent. Cells from an aggregating strain adhered to fish and human tissue culture cell monolayers in significantly larger numbers (30 fold) than cells from nonaggregating strains. No differences were detected in acetic acid degraded 0-antigen polysaccharide or Bovien-type antigens from aggregating and nonaggregating strains of A. salmonicida using double immunodiffusion. Immunodiffusion also failed to detect any antigens in aggregating strains which might be associated with the additional layer. Such an antigen was detected in agglutination assays following agglutinin adsorption procedures using a rabbit anti- A. salmonicida serum. This antigen was not discernable in similar assays with antiserum from juvenile coho salmon. Thermal stress of the host and dosage of A. salmonicida were important parameters in water-borne challenge experiments. Actively immunized juvenile coho salmon, and those receiving juvenile coho salmon antiserum produced to the challenge strain, were significantly protected from furunculosis when challenged in the laboratory. Under natural challenge conditions (at the Oregon Department of Fish and Wildlife's Siletz River Salmon Hatchery) four A. salmonicida vaccines were evaluated. The parenterally administered vaccine significantly reduced the furunculosis mortality while three different oral vaccines provided no protection. |
Genre | Thesis/Dissertation |
Topic | Aeromonas salmonicida |
Identifier | http://hdl.handle.net/1957/43794 |