Effect of rChymotrypsin on nascent S. epidermidis 1457 and 5179-R1 and S. aureus SA113 biofilms (a) and preformed S. epidermidis 1457 and 5179-R1 and S. aureus SA113 biofilms (b). Significant effects were seen on nascent S. epidermidis 5179-R1 and S. aureus SA113 biofilm formation (*, P < 0.05), but on the preformed biofilms, rChymotrypsin had a significant effect only on S. epidermidis 5179-R1 (*, P < 0.05). OD550, optical density at 550 nm. Error bars indicate the standard errors of the means.