Abstract: Recombinant vectors comprising the cell entry region of the Shigella ox EIEC invasion plasmid are provided, as well as, Shigella or EIEC strains comprising the recombinant vectors. The vectors provide an improved platform for developing attenuated vaccine strains of Shigella or EiEC and for delivering other foreign proteins of interest. The recombinant vectors and bacterial strains comprising the same may be used in methods of inducing an immune response.

Abstract: Recombinant vectors comprising the cell entry region of the Shigella ox EIEC invasion plasmid are provided, as well as, Shigella or EIEC strains comprising the recombinant vectors. The vectors provide an improved platform for developing attenuated vaccine strains of Shigella or EiEC and for delivering other foreign proteins of interest. The recombinant vectors and bacterial strains comprising the same may be used in methods of inducing an immune response.

Abstract: “Black holes” in the genomes of bacterial pathogens represent deletions of “anti-virulence” genes, i.e. genes that are detrimental to a pathogenic lifestyle. Identification of the missing genetic loci in the “black hole” identifies genes that are incompatible with the bacteria's pathogenicity. These genes, their gene products, and compounds generated by the enzymatic action of these gene products represent potential new compounds that are inhibitory to the bacterial pathogen and thus useful as pharmaceuticals. The utility of this concept is demonstrated in the missing gene for lysine decarboxylase, and the resulting inhibitory activity of cadaverine (the diaminoalkyl reaction product of lysine decarboxylase) on the Shigella enterotoxins. Diaminoalkyl compounds are therefore potent inhibitors of E. coli and Shigella spp. enterotoxins. Lysine decarboxylase generated from the gene cadA results in attenuation of the enterotoxic effects.

Abstract: “Black holes” in the genomes of bacterial pathogens represent deletions of “anti-virulence” genes, i.e. genes that are detrimental to a pathogenic lifestyle. Identification of the missing genetic loci in the “black hole” identifies genes that are incompatible with the bacteria's pathogenicity. These genes, their gene products, and compounds generated by the enzymatic action of these gene products represent potential new compounds that are inhibitory to the bacterial pathogen and thus useful as pharmaceuticals. The utility of this concept is demonstrated in the missing gene for lysine decarboxylase, and the resulting inhibitory activity of cadaverine (the diaminoalkyl reaction product of lysine decarboxylase) on the Shigella enterotoxins. Diaminoalkyl compounds are therefore potent inhibitors of E. coli and Shigella spp. enterotoxins Lysine decarboxylase generated from the gene cadA results in attenuation of the enterotoxic effects.

Abstract: “Black holes” in the genomes of bacterial pathogens represent deletions of “anti-virulence” genes, i.e. genes that are detrimental to a pathogenic lifestyle. Identification of the missing genetic loci in the “black hole” identifies genes that are incompatible with the bacteria's pathogenicity. These genes, their gene products, and compounds generated by the enzymatic action of these gene products represent potential new compounds that are inhibitory to the bacterial pathogen and thus useful as pharmaceuticals. The utility of this concept is demonstrated in the missing gene for lysine decarboxylase, and the resulting inhibitory activity of cadaverine (the diaminoalkyl reaction product of lysine decarboxylase) on the Shigella enterotoxins. Diaminoalkyl compounds are therefore potent inhibitors of E. coli and Shigella spp. enterotoxins. Lysine decarboxylase generated from the gene cadA results in attenuation of the enterotoxic effects.

Abstract: The present invention relates to our discovery that the mxiM protein of Shigella flexneri is indispensable for the spread of Shigella from cell to cell. Thus, the invention provides the mxiM protein or peptides or portions thereof as antigens in vaccines to prevent Shigella infections and treat hosts infected with Shigella by inhibiting intercellular spread. In another aspect, the invention relates to antibodies generated against the mxiM proteins, peptides, or portions thereof to detect Shigella in contaminated food and water supplies as well as in infected hosts. The present invention also describes a method called the TIER (test of intracellular expression requirements) for determining the intracellular expression requirements of genes and therefore, permitting one to establish the role of genes in the pathogenesis of organisms. A method of detecting Shigella or Shigella mxiM DNA in a sample using a mxiM DNA probe is also described.