The impact of EcO157 on biofilm community β-diversity.

aThe β-diversity (mean ± standard error, n = 3) of each biofilm community was calculated based on Euclidean index. Different letters after the means indicate statistical difference at P<0.05 by least significant distance (LSD) test with Holm–Bonferroni adjustment when the interaction effect was significant by PANOVA. bPermutational analysis of variance (PANOVA) of β-diversity to test for effect of EcO157, time, and their interaction on community dissimilarity.