Fig. 1

The schematic diagram of S. Typhimurium derived OMV displaying mixed heterologous O-antigens induce an immune response in mice. Two recombinant plasmids synthesizing different E. coli O-antigens were introduced into engineered Salmonella to isolate OMV. The mice were immunized with OMV displaying mixed E. coli O-antigen by intraperitoneal injection. The O-antigen-specific IgG antibodies induced by our OMV possess significant biological functionality to provide protection against the infection of wild-type E. coli