A discrete factor A is detected on Vibrio cholerae Non-O1, O:139 by laser flow cytometry.

A new serogroup of Vibrio cholerae non-O1, O:139, has been implicated in recent epidemics. It was scanned with a factor A-specific fluoresceine-conjugated monoclonal antibody, searching for antigen determinants by laser flow cytometry. First, a group of gram-negative 4-amine-4, 6 dideoxy-D-mannose antigen-related microorganisms were tested to assess monoclonal antibody cross reactions. Later, a clear recognition of antigen determinants was found with this monoclonal antibody, on V. cholerae non-O1, O:136, Bengal, and MO45 strains, showing no cross reactions with the antigenically related non O1, O:22, and Inaba and Ogawa O1 strains. On the other hand, factor A of V. cholerae O1 strains was recognized by the specific monoclonal antibody and a discrete factor A on V. cholerae non-O1, O:139, Bengal and MO45 strains was detected.