Large plasmids associated with virulence in Shigella species have a common function necessary for epithelial cell penetration

Abstract

Large plasmids (120 to 140 megadaltons) associated with virulence of Shigella sonnei, S. flexneri 2a and S. dysenteriae 1 were transferred from each strain into Escherichia coli K-12 and avirulent S. flexneri 1b strains by ampicillin transposon (Tn1)-mediated conduction. Strains with the virulence plasmid could penetrate tissue culture cells irrespective of the original host of the plasmid.