Effect of the zinc on the biofilms formed by typical EAEC strains isolated from children with diarrhea and controls. The data represent the average percent reduction in biofilm formation obtained after three independent assays at least. Solid squares represent the reduction displayed by strains recovered from persistent diarrhea (> 14 days); solid circles represent the reduction displayed by strains recovered from diarrhea lasting 12 days; and open circles represent the reduction displayed by strains isolated from diarrhea lasting 10 days or less. Reductions in biofilm formation displayed by strains isolated from healthy children are represented by triangles. Dotted line indicates the average reduction displayed by the prototype EAEC strain 042.