Purification, Characterization And Gene Location Of W Pili From Aeromonas Hydrophila J-1 Strain

W pili of Aeromanas hydroph i/a .1-I strain was purified by treatment of 30% (NH4)2S04 and Sephadex G- 100. Expression conditions, biochemical and biological characters and gene location of W pill were detected. In 280C expression of W pili was better in TSB and LB than that in nutrient broth. During precipitating of W pill by (NH4)2S04, 50% was prior to 30%. W pili showed a single subunit protein with MW 20,000 by SDS-PAGE. After staining of Schiff agent, W pill were negative and had no polysaccharide. The antibody titer of the sera of rabbit which was immunized with the gel containing W pill reached 1:32. The haemagglutination of Aeromonas hydrophila J- 1 strain to RBCs of rabbit or chicken was not inhibited by mannose. The results of adhesion and adhesion inhibition tests of EPC and HEp-2 cells showed the adhesin receptor had some mannose and choleterin but no glucose. The adhesion was mediated mainly by W pili. About 80% adhesion was inhibited by the application of the anti-W pill antibody alone, and almost total inhibition occurred by using of the antibodies of S-layer, OMP and W pill together. Gene fragments of Aeromonas hydrophila J-l strain were introduced to E coil DH5 a . A colony inserted with a 2.0Kb fragment expressing W pill dime was detected. It showed that the inserted fragment contained the W phi gene.