Bk. Gudmundsdottir et B. Magnadottir, PROTECTION OF ATLANTIC SALMON (SALMO-SALAR L) AGAINST AN EXPERIMENTAL-INFECTION OF AEROMONAS-SALMONICIDA SSP ACHROMOGENES, Fish & shellfish immunology, 7(1), 1997, pp. 55-69
To assess the protective role of cell-associated and extracellular ant
igens of Aeromonas salmonicida ssp. achromogenes, Atlantic salmon were
immunised either with detoxified extracellular products (d-ECP), form
alin killed cells (f-Cells) or a mixture of both. In an experimental c
hallenge ECPs were found to elicit better protection than whole bacter
ia. The protection strongly correlated with the detection of antibodie
s directed against a toxic metallo-caseinase, AsaP1, in fish sera. Pas
sive immunisation of Atlantic salmon with rainbow trout or rabbit anti
-AsaP1 antisera conferred significant protection against challenge wit
h a virulent A. salmonicida ssp. achromogenes strain. In an equivalent
experiment neither rainbow trout nor rabbit antisera containing antib
odies to the A-layer protein of A. salmonicida were found to be protec
tive for passively immunised Atlantic salmon. The results demonstrate
the importance of humoral antibodies and neutralisation of bacterial t
oxins in protecting Atlantic salmon against A. salmonicida ssp. achrom
ogenes. (C) 1997 Academic Press Limited.