Susceptibility of three different strains of juvenile
Atlantic halibut (Hippoglossus hippoglossus L.) cultured at two
different temperatures to Vibrio anguillarum and temperature effect
on antibody response
R.
Hoare, H. Hovland, A.L. Langston , A.
Imsland, S.O. Stefansson, M. Mulcahy,
H.I. Wergeland-2002
Fish & Shellfish Immunology, 13(2): 111-123
Abstract:
Three
geographically distinct-reared strains (Canadian, Icelandic,
Norwegian) of juvenile Atlantic halibut (Hippoglossus hippoglossus
L.) cultured at optimal and super-optimal growth
temperatures (12 and 18°C respectively), were
challenged with a virulent isolate of Vibrio anguillarum
by injection. The halibut were injected
intraperitoneally with 100µl of the bacterial
suspension (1×106 cells per fish). After challenge,
temperature and strain-related differences in survival
were observed. Canadian and Icelandic halibut cultured
at the super-optimal temperature of 18°C were
significantly more susceptible to infection than those
strains cultured at 12°C. Total mortality at 18°C
for the Canadian and Icelandic strains was 56·4
and 61·85% respectively, compared to 32 and 26·6%
respectively at 12°C. Norwegian halibut were
significantly more resistant to infection with V.
anguillarum at 18°C compared to the other
strains, with total mortality of 13·3%. There was no
significant difference in total mortality of Norwegian
halibut at 18 or 12°C (13·3, 25% respectively).
The
specificity of the antibodies in sera from challenged halibut
cultured at 18°C was primarily to LPS. Immunoblots
showed the presence of antibodies against O-side chain
antigens. This reaction was strongest in sera from the
Norwegian halibut strain compared with the Canadian
and Icelandic halibut, which suggests that the
difference in resistance to challenge may be
ascribable to the presence of antibodies to LPS.
Specific antibody levels, as measured by ELISA, increased
with increasing temperature and strain differences
were apparent, however these did not relate to disease
resistance.
(Aquaculture
Development Centre, Department of Zoology and Animal Ecology, National
University of Ireland, Lee Maltings, Cork, Ireland)