Characterization of a Verocytotoxin-Producing Enteroaggregative Escherichia coli Serogroup O111:H21 Strain Associated with a Household Outbreak in Northern Ireland

A strain of Escherichia coli O111:H21 recently isolated in the United Kingdom harbored the phage-encoded vtx2c gene and the aggregative adherence plasmid. Although exhibiting the same pathogenic profile as the E. coli O104:H4 strain linked to the outbreak in Germany, there were important differences in strain characteristics and in the epidemiological setting.