Abstract
Lipopolysaccharide (LPS), which consists of three major components, i.e. lipid A, a core polysaccharide and an O-antigen, is an antigenic constituent of the cell walls of Gram-negative bacteria. For example, the effects of LPS from Aeromonas hydrophila have been examined following immersion vaccination of carp, Cyprinus carpio L., and injection of toadfish, Opsanus tau L. In addition, Salati, Ikeda & Kusuda (1987) reported that crude LPS from Edwardsiella tarda enhanced the phagocytic activity of leucocytes following injection into eels. LPS has also been attributed with mitogenic activity of lymphocytes, and has enhanced the effects of C-reactive protein. This study has sought to examine the effects of LPS from a fish-pathogenic isolate of Cytophaga -like bacterium (CLB) on the protective immune response of turbot. Turbot, Scophthalmus maximus (L.), of 20 g average size, were obtained from a commercial fish farm. The animals were maintained in glass aquaria containing aerated re-circulating sea water at 16-18 degree C. The turbot were fed daily with a commercial diet.