scholarly journals Effects of Cortisol implants on the susceptibility and the histopathology of the responses of naive coho salmon Oncorhynchus kisulch to experimental infection with Lepeophtheirus salmonis (Copepoda: Caligidae)

1992 ◽  
Vol 14 ◽  
pp. 195-205 ◽  
Author(s):  
SC Johnson ◽  
LJ Albright
Keyword(s):  
Experimental Infection ◽  
Coho Salmon ◽  
Lepeophtheirus Salmonis ◽  
Cortisol Implants

Viral Hemorrhagic Septicemia: Comparative Susceptibility of Rainbow Trout (Salmo gairdneri) and Hybrids (S. gairdneri × Oncorhynchus kisutch) to Experimental Infection

1976 ◽  
Vol 33 (5) ◽  
pp. 1205-1208 ◽  
Author(s):  
Wilma M. Ord ◽  
Monique Le Berre ◽  
Pierre de Kinkelin
Keyword(s):  
Rainbow Trout ◽  
Experimental Infection ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Viral Hemorrhagic Septicemia ◽  
Comparative Susceptibility

Rainbow trout (Salmo gairdneri) fry and yearlings were compared with hybrids of rainbow trout and coho salmon (Oncorhynchus kisutch) for susceptibility to viral hemorrhagic septicemia (VHS). In three trials, exposure to waterborne infectivity consistently resulted in a 77% mortality of rainbow trout fry while loss among the hybrid fry averaged only 11%. Tests showed survivors might be carriers of virus. Hybrid yearlings infected by gill brushing were fully refractory to VHS whereas mortality (3:8) and viremia were recorded among gill-infected rainbow trout yearlings.

Relation of Water Temperature to Flexibacter columnaris Infection in Steelhead Trout (Salmo gairdneri), Coho (Oncorhynchus kisutch) and Chinook (O. tshawytscha) Salmon

1975 ◽  
Vol 32 (9) ◽  
pp. 1553-1559 ◽  
Author(s):  
R. A. Holt ◽  
J. E. Sanders ◽  
J. L. Zinn ◽  
J. L. Fryer ◽  
K. S. Pilcher
Keyword(s):  
Water Temperature ◽  
Experimental Infection ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Disease Process ◽  
Salmo Gairdneri ◽  
Contact Method ◽  
Steelhead Trout ◽  
Time To Death

The effect of water temperature upon mortality from experimental infection by Flexibacter columnaris and on mean time to death was investigated in juvenile steelhead trout (Salmo gairdneri), coho salmon (Oncorhynchus kisutch), and spring chinook salmon (Oncorhynchus tshawytscha). Eight temperatures increasing from 3.9 to 23.3 C (39 to 74 F) by increments of 2.8 C (5 F) were studied. Fish were infected by the direct contact method whereby a suspension of the pathogen was added to the water. It was found that at temperatures of 9.4 C (49 F) and below, no deaths due to the experimental infection with F. columnaris occurred. At 12.2 C (54 F) mortality varied from 4 to 20% among the three species, and increased progressively with increasing temperature to 100% in steelhead trout and coho salmon at 20.5 C (69 F), and 70% in chinook salmon at that temperature. With all three salmonid species, an inverse linear relationship was found between water temperature and the log10 of the mean number of days from exposure to death. This means that as the temperature increased above 12.2 C (54 F), the disease process was progressively accelerated, resulting in a minimum time to death at 20.5 or 23.3 C (69 or 74 F) and a maximum at 12.2 C (54 F). The results indicate that under the conditions of these experiments, columnaris disease in salmonids was completely suppressed by water temperatures of 9.4 C (49 F) or below.

ACTIVE AND PASSIVE IMMUNIZATION OF CERTAIN SALMONID FISHES AGAINST AEROMONAS SALMONICIDA

1965 ◽  
Vol 11 (3) ◽  
pp. 397-405 ◽  
Author(s):  
K. D. Spence ◽  
J. L. Fryer ◽  
K. S. Pilcher
Keyword(s):  
Rainbow Trout ◽  
Causative Agent ◽  
Experimental Infection ◽  
Coho Salmon ◽  
Age Groups ◽  
Passive Immunization ◽  
Aeromonas Salmonicida ◽  
Salmonid Fishes ◽  
Passive Protection ◽  
Two Age Groups

Passive protection against Aeromonas salmonicida, the causative agent of furunculosis in fishes, was produced in juvenile coho salmon by administration of serum from adult rainbow trout containing antibodies actively produced by intra-abdominal vaccination.The levels of natural (or residual) agglutinins against A. salmonicida and those produced by vaccination are shown for two age-groups of rainbow trout.Oral vaccine administered in the diet of juvenile coho salmon failed to produce either agglutinating antibody or protection against experimental infection under the conditions employed.

Changes in the Immune System of Coho Salmon (Oncorhynchus kisutch) during the Parr-to-Smolt Transformation and after Implantation of Cortisol

1987 ◽  
Vol 44 (1) ◽  
pp. 161-166 ◽  
Author(s):  
Alec G. Maule ◽  
Carl B. Schreck ◽  
Stephen L. Kaattari
Keyword(s):  
Atpase Activity ◽  
Plasma Cortisol ◽  
Coho Salmon ◽  
Vibrio Anguillarum ◽  
Oncorhynchus Kisutch ◽  
Primary Immune Response ◽  
Normal Density ◽  
Low Density ◽  
Splenic Lymphocytes ◽  
Cortisol Implants

The primary immune response of coho salmon (Oncorhynchus kisutch), as assessed by the production of splenic antibody-secreting cells (plaque-forming cells, PFC) after an injection of Vibrio anguillarum O-antigen, decreased during smoltification. This period was marked by increases in gill Na+-K+-adenosine triphosphatase (ATPase) activity and plasma thyroxine and cortisol titers. Numbers of leucocytes relative to erythrocytes in peripheral blood and splenic lymphocytes relative to fish body weight were also reduced. Fish reared at normal hatchery density (approximately 2 fish∙L−1) appeared to have reduced rates of development and higher numbers of PFC than fish reared at one-third normal density. Moreover, in fish changed from normal density to low density 2 wk before sampling, ATPase activity and plasma thyroxine levels were equal to those in fish reared continuously at normal density, but plasma cortisol levels and PFC were equal to those in fish reared at low density. Fish with cortisol implants had higher plasma cortisol titers, reduced numbers of splenic PFC, splenic lymphocytes, and circulating leucocytes, and greater mortality when fish were exposed to V. anguillarum.

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

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