Antibacterial and Antibiofilm Surfaces through Polydopamine-AssistedImmobilization of Lysostaphin as an Antibacterial Enzyme.

Antibioticresistance and the colonization of bacteria on surfaces,often as biofilms, prolong hospitalization periods, increase mortality,and are thus major concerns for health care providers. There is anurgent need for antimicrobial and antibiofilm surface treatments thatare permanent, can eradicate both biofilms and planktonic pathogensover long periods of time, and do not select for resistant strains.In this study, we have demonstrated a simple, robust, and biocompatiblemethod that utilizes the adhesive property of polydopamine (PDA) tocovalently attach the antimicrobial enzyme lysostaphin (Lst) to avariety of surfaces to generate antibacterial and antibiofilm interfaces.The immobilization of the recombinant Lst onto PDA-coated surfaceswas carried out under physiological conditions, most probably throughthe C-terminal His6-tag fragment of the enzyme, minimizing the lossesof bioagent activity. The modified surfaces were extensively characterizedby X-ray photoelectron spectroscopy and peak force quantitative nanomechanicalmapping (PeakForce QNM) AFM-based method, and the presence of Lston the surfaces was further confirmed immunochemically using anti-Lstantibody. We also found that, in contrast to the physically adsorbedLst, the covalently attached Lst does not leach from the surfacesand maintains its endopeptidase activity to degrade the staphylococcalcell wall, avoiding most intracellular bacterial resistance mechanisms.Moreover, the Lst-coated surfaces kill hospital strains of Staphylococcus aureusin less than 15 min and prevent biofilmformation. This immobilization method should be applicable also toother proteins and enzymes that are recombinantly expressed to includethe His6-tag fragment. [ABSTRACT FROM AUTHOR]