Dispersal of established biofilms by Proteinase K.

Strains tested are shown along the x-axis and grouped based on methicillin-sensitivity and isolation source. The indicated strains were grown statically for 24 hours to allow biofilm formation. Wells were washed and treated with buffer alone (- Prot. K) or 100 µg/ml Proteinase K (+ Prot. K) for 2 hours. Biofilm formation was then quantified by standard microtiter assays and measuring the absorbance at 538 nm, plotted along the y-axis. Bars represent the average absorbance obtained from at least 3 independent plates representing biological replicates; error bars represent the SEM. Asterisks (*) denote a p-value less than 0.05 between the treated and untreated groups.