Dispersal of Bap-mediated Staphylococcus aureus biofilm by proteinase K

The dominant role of biofilm-associated protein (Bap) in Staphylococcus aureus biofilm development prompted us to investigate Bap as a potential target for proteinase-mediated biofilm dispersion. Biofilm assay in microtitre plates showed that proteinase K hampered the early adhesion of cells as well as biofilm development. Proteinase K treatment of 24- and 48-h-old biofilms showed enhanced dispersion of bap-positive S. aureus biofilm; however, proteinase K did not affect the bap-negative S. aureus biofilm. When antibiotics were used in combination with proteinase K, significant enhancement in antibiotic action was noticed against bap-positive S. aureus biofilm. This study establishes that antibiotics in combination with proteinase K can be used for controlling S. aureus biofilms in whose development Bap surface protein has a major role. We propose that Bap protein could be a potential target for therapeutic control of S. aureus infections (for example, bovine mastitis). The Journal of Antibiotics (2013) 66, 55-60; doi:10.1038/ja.2012.98; published online 14 November 2012