Extracellular proteases ECP of Aeromonas salmonicida and their significance in the pathogensis and immuno-prophylaxis of fish furunculosis

Many bacteria, including those of the Aeromonas family, produce and secrete various extra-cellular substances, including enzymatic proteins, which are often egzotoxic in nature. This article describes the characteristics of e xtracellular proteases ECP of the Aeromonas salmonicida subspecies salmonic ida, their importance in pathogenesis of salmonids furunculosis and their i mmunogenic activity. Of the entire range of extracellular proteases (ECP), the most important in terms of their furunculosis pathogenesis are: serine protease, glycerophospholipide: cholesterol acylotransferase (GCAT) and met aloprotease. The toxic level of GCAT for fish increases if it appears in a lipopolysaccharide LPS complex, The pathogenicity of this complex increases even more under the influence of serine protease, The significance of meta loprotease in pathogenesis of furnunculosis lies in the fact that it destro ys collagen in fish tissues. Research on the immunogenic activity of extrac ellular proteases ECP and the possibility of using them in immune prophylak is of salmonids furnunculosis has so far not show satisfactory results, The most promising seems to be the antigen properties of the GCAT/LPS complex. There is also a possibility of using the immunostimulatory effect of the w hole range of ECP proteases, Nonetheless, the heterogeneity of this protein requires further research on modifying the ECP in such a way that it would contain a majority of antibodies against A. salmonicida subsp. salmonicida , This would allow the ECP antigen to increase its activity.