Methicillin-resistant Staphylococcus aureus (MRSA) infections are a particular problem in hospitals and other healthcare environments. MRSA can survive on normal surfaces and fabrics but researchers at Rensselaer Polytechnic Institute have now developed a coating that kills MRSA on contact. The coating contains lysostaphin linked by a short flexible polymer to carbon nanotubes and can be applied to surgical equipment, hospital walls, door handles and other surfaces. Lysostaphin is an example of a bacteriocin, a defensive bacterial antimicrobial agent that kills other, often closely related, bacteria. Lysostaphin, a cell wall-degrading enzyme, is produced by non-pathogenic strains of Staphylococcus bacteria and is very effective against Staphylococcus aureus, including MRSA, but completely harmless to humans and other organisms.
The lysostaphin-nanotube conjugate can be mixed with a wide range of surface finishes – in the present study, latex house paint was used. In tests, 100% of MRSA were killed within 20 minutes of contact with the paint. Treated surfaces can be washed repeatedly without losing their effectiveness and the team believe that the new coating is likely to prove superior to coatings that release biocides or those that ‘spear’ bacteria using amphipathic polycations and antimicrobial peptides. The team also believe that is unlikely that Staphylococcus aureus will be able to develop resistance to lysostaphin.
The study is published in the journal ACS Nano.