FIG 4.

DNase I reduces MRSA biofilm. (A) Role of extracellular DNA (eDNA) on early biofilm formation for MRSA strains. Results are expressed as relative differences (equation 1) in the amounts of biofilm as measured by the BioFilm Ring Test after 6 h of incubation in the presence of DNase compared with untreated control strains. Data represent means and the corresponding standard errors of two independent experiments analyzed in duplicate. ***, P < 0.001, using the Mann-Whitney test. (B) Quantification of eDNA in MRSA biofilm cultures. Black bars and dots represent medians and quartiles.