SmaI (A) and KpnI (B) PFGE patterns of selected C. jejuni and C. coli strains isolated in association with waterborne outbreaks 1, 2, and 3. Lanes 1 and 2, patient isolates from outbreak 1; lane 3, drinking water isolate from outbreak 1; lanes 4 and 5, patient isolates from outbreak 2; lane 6, lake water isolate from outbreak 2; lanes 7, 8, and 9, patient isolates from outbreak 3; lane 10, C. jejuni isolate from well 2; lane 11, C. coli isolate from well 1; lane 12, C. coli isolate from dike; lane 13, C. coli isolate from a well at a farm; lane 14, C. jejuni isolate from duck pond; lanes mw, molecular weight markers.