Lability of the pAA Virulence Plasmid in Escherichia coli O104:H4: Implications for Virulence in Humans

Abstract

The pAA plasmid can be lost by E. coli O104:H4 outbreak strain in the human gut in the course of disease. pAA loss might attenuate virulence and diminish the ability to cause HUS. The pAA instability has clinical, diagnostic, epidemiologic, and evolutionary implications.