α₂-Macroglobulin In Seven Species Of Cultured Fish

Aeromonas hydrohila (Ah) was considered as a major pathogen for culture fishes, Extracelluar protease (ECPase)was an important virulence factor of Ah. It is generally recognized that Ctenopharyngodon idellus show particular resistance to Ah. In order to study the biological basis of this resistance, seven spicies of cultured fishes, Ctenopharyngodon idellus, Carassius auratus, Hypophthalmichthys molotrix, Glorias fuucus, AHstichthys nobilis, Micropterus salmoides, Monopteurs albus were chosen, and serum samples were investigated for α2-Macroglobulin.Skim milk proteolysis inhibition test was used to detect serum Ah ECPase inhibitory activity; BAPNA dyeing test was established to screen for the presence of a 2-Macroglobulin; analysis of the a 2-Macroglobulin actvity showed that Monopteurs albus and Ctenopharyngodon idellus had the high a 2-Macroglobulin actvity; the in vitro protective effect of a 2M on HEp-2 cells indicated that a 2M could neutralize the Ah ECPase cytotoxic activities.The results suggested that a 2M could be an important protective factor against Aeromonas hydrophlia.