Molecular Characterization of Enterohemorrhagic E. coli O157 Isolated from Animal Fecal and Food Samples in Eastern China

Figure 1

Biofilm formation by EHEC O157 isolates. Biofilm formation by EHEC O157 isolates on polypropylene microtiter plates following incubation for 24 h at 37°C in LB broth without salt (LB-NS). All experiments were repeated at least three times. The columns represent the mean ± standard deviations of the data. Comparisons of the OD values produced by bacterial biofilms to the ODc values were used to classify the strains (non-biofilm producer, weak, moderate, or strong). The cut-off OD (ODc) value was defined as three standard deviations above the mean OD of a blank control. Strains were classified as follows: OD < ODc = no biofilm production; ODc < OD < (2 ODc) = weak biofilm producer; (2 ODc) < OD < (4 ODc) = moderate biofilm producer; and (4 ODc) < OD = strong biofilm producer.