[Purification and identification of pili of Vibrio cholera O139]

To provide the base of manufacturing V. cholera O139 subunit vaccine, purification and identification methods of V. cholera O139 Toxin-coregulated pili (TCP) were studied. The results showed the optimal expressing condition of TCP was in AKI or CFA medium, at 30 C for 24-36 h with stationary cultivation. The molecular weight of the TCP subunit protein measured by sodium dodecyl sulfate-poly acrylamide gel electrophoresis was about 20.5 kd. By using mouse anti-TCP monoclone antibody and sheep anti-mouse IgG-HRP antibody, the TCP was confirmed by dot blot immunoassay. Rabbit immune serum of TCP purified from O139 strain agglutinated both O139 biotype and El Tor biotype Vibrio cholera strains. These indicate that TCP may be an effective and protective antigen to conduct the preparation of V. cholera vaccine.