Plasmid coding for drug resistance and invasion of epithelial cells in enteropathogenic Escherichia coli 0111:H−

EnteropathogenicEscherichia coli(EPEC) can adhere to, invade and multiply in human epithelial cells. To define the elements required for bacterial invasion, we isolated from an 0111:HEPEC a 6.6 kb plasmid that is capable of conferring to an avirulent, non-adherentE. coliK12 strain (DK1) the capacity to invade epithelial cells. With this system a dissociation was possible between bacterial invasion and adherence to epithelial cells. Bacteria containing this plasmid synthesise a protein of 32 kDa (pI 4.93) which seemed to be required for cell invasion. The results provide a new basis for strategies to prevent EPEC infections.