Record Details
Field | Value |
---|---|
Title | Strain differentiation and detection of infectious hematopoietic necrosis virus |
Names |
LaPatra, Scott Edward
(creator) Fryer, John L. (advisor) |
Date Issued | 1989-05-05 (iso8601) |
Note | Graduation date: 1989 |
Abstract | The virulence of selected isolants of infectious hematopoietic necrosis virus (IHNV) were differentiated and correlated with electrophoretic mobilities of virion structural proteins by sodium dodecylsulfate polyacrylamide gel electrophoresis. A type 1 electropherotype of IHNV was more virulent for kokanee salmon (Oncorhynchus nerka) and a type 2 strain more virulent for rainbow trout (Oncorhynchus mykiss). Viruses from the Columbia River basin (electropherotypes 2 and 3) were more virulent for steelhead trout (Oncorhynchus mykiss) and IHNV electropherotypes from southern Oregon and California (type 3) were most virulent for chinook salmon (Oncorhynchus tshawytscha). Microscopic pathology induced by type 1 and 3 strains of IHNV in rainbow trout was less severe and involved fewer tissues than that caused by a type 2 providing further evidence that type 2 strains are more pathogenic for rainbow trout. A fluorescent antibody test (FAT) was developed for the rapid detection of IHNV. The FAT was used for the detection of IHNV in blood smears and organ imprints from clinically infected juveniles and IHNV-infected cells in ovarian fluid from adult carriers. The test was equal in sensitivity to the plaque assay method and required less time to obtain a definitive diagnosis. Other sources of virus examined included cells contained in the ovarian fluid (OF) of sexually mature steelhead trout. Ovarian fluid collected from spawning steelhead trout determined to be virus-free tested viruspositive when reexamined post-spawning. Results indicated that cells free in OF allowed replication of IHNV and could be used in diagnostic tests to detect this delayed virus expression. Infectious hematopoietic necrosis virus was also detected in mucus obtained from naturally infected juvenile and adult salmonids. In adult chinook and kokanee salmon, a higher prevalence of virus was detected in mucus collected from the external surface of fish than observed in OF, seminal fluid, or spleen tissue homogenates. Experimental infection of juvenile rainbow trout suggested IHNV detected in mucus was a result of the normal progression of disease and that the integument may have been a site of virus replication and a possible portal of entry. |
Genre | Thesis/Dissertation |
Topic | Rhabdoviruses |
Identifier | http://hdl.handle.net/1957/41766 |