Characterization of a Recurrent Clonal Type of Escherichia coli O157:H7 Causing Major Outbreaks of Infection in Scotland

A particular recurrent clonal type of Escherichia coli O157 has been isolated from multiple clinical, veterinary, food, and environmental sources throughout Scotland since 1989. Significant genotypic variation was detected among isolates from distinct outbreaks, with the presence or absence of single fragments being sufficient to delineate outbreak groups within the clonal type.