FIG. 2.

Response of E. coli O157:H7 isolate 43894 to irradiation treatments. Planktonic cells (filled symbols) and biofilm-associated cells (open symbols) were evaluated after 24 h (circles), 48 h (squares), and 72 h (triangles) of cultivation. Bars indicate standard errors, n = 9 for each point of measurement. Lines indicate the linear regression for planktonic cells at 24 h (solid line), 48 h (long-dash line), or 72 h (short-dash line); biofilm-associated cells at 24 h (dotted line), 48 h (dash-single-dot line), or 72 h (dash-double-dot line).