HUS=hemolytic uremic syndrome; VT= Vero cytotoxin; RFLP=restriction fragment length polymorphisms; PFGE=pulsed field gel electrophoresis
^aInvestigation of the epidemiology of two outbreaks has been reported previously (11,12)
^bDetermined by hybridization with digoxigenin-labeled polynucleotide probes for VT1 and VT2 genes (2,3).
^cBased on polymerase chain reaction amplification with a sense primer specific for either the VT2 or VT2c sequence and a degenerate antisense primer that would anneal to known VT2 sequences (14).
^dHybridization with a probe comprising digoxigenin-labelled fragments of the VT2-encoding bacteriophage from strain E32511(15). Patterns were designated according to the phage type of the strain and a letter denoting a unique pattern type. The PT2-Avar pattern differed from PT2-A by the possession of a single extra hybridizing fragment.
^eProfiles of XbaI digested genomic DNA. Patterns were designated according to the phage type of the strain and differentiated by number. Thus patterns PT2-1, PT2-2, PT2-3, and PT2-4 differed from each other by at least three fragment positions. Where there were single unique band differences from PT2-1 these were designated PT2-1a, etc.
^fThe designation RDNC indicates that the strain reacts with the typing phages but does not conform to a currently defined pattern.