SPINK1 and vibrio infectious disease: We have developed strains of V. cholerae that show potential to be used in a new oral, whole cell killed cholera vaccine that includes two clinical isolate O1 El Tor variant strains, an Ogawa and Inaba serotype, each containing cholera toxin gene deletions and a rhamnose-inducible tcp operon, such that a vaccine can be prepared that is non-toxigenic and includes the protective antigen toxin-coregulated pilus following culture in an animal-free medium supplemented with 0.1% rhamnose in addition to the cell wall antigens found in the current killed oral vaccines.