Enteroadhesion fimbriae and enterotoxin of Escherichia coli: genetic transfer to a streptomycin-resistant mutant of the galE oral-route live-vaccine Salmonella typhi Ty21a.

An enterotoxigenic Escherichia coli plasmid encoding colonization factor antigen (CFA) I fimbriae and heat-stable toxin was transferred into a streptomycin-resistant mutant of the Salmonella typhi galE strain Ty21a (a live attenuated oral typhoid vaccine). The virulence plasmid-carrying transconjugants produced CFA I fimbriae and heat-stable toxin. The marked production of CFA I fimbriae was observed even in a vaccine medium for Ty21a. The data lead to a new type of potential live oral vaccine, S. typhi Ty21a producing enteroadhesion fimbriae.