FIG. 3.

PFGE patterns of the 44 O157 isolates from 22 outbreaks. Isolate numbers are indicated above the gel. Note that isolates G5312, G5311, G5306, G5305, G5290, and G5289 could not be typed by PFGE (and are grouped together at the bottom of Fig. ). The bacteriophage lambda DNA ladder standard for PFGE applications (Bio-Rad) was used. Molecular sizes (in kilobase pairs) are shown to the right.