A second large plasmid encodes conjugative transfer and antimicrobial resistance in O119:H2 and some typical O111 enteropathogenic Escherichia coli

Department of Biology, Haverford College, PA, USA; The Wellcome Trust Sanger Institute, Cambridgeshire, United Kingdom

^* To whom correspondence should be addressed. Email: iokeke{at}haverford.edu.

	Abstract

A novel and functional conjugative transfer system, identified in O119:H2 enteropathogenic Escherichia coli (EPEC) strain MB80 by subtractive hybridization, is encoded on a large multi-drug resistance plasmid, distinct from the well-described EPEC adherence factor plasmid (EAF). Variants of the MB80 conjugative resistance plasmid were identified in other EPEC, including prototypical O111:NM strain B171, from which the EAF plasmid has been sequenced. This separate large plasmid, and the selective advantage that it confers in the antibiotic era, have been overlooked because it co-migrates with the virulence plasmid on conventional gels.