Lysostaphin is a Staphylococcus simulans metalloendopeptidase. It can function as an antimicrobial against Staphylococcus aureus. Lysostaphin is a 27 KDa glycylglycine endopeptidase, an antibacterial enzyme which is capable of cleaving the crosslinking pentaglycin bridges in the cell wall of Staphylococci. Lysotaphin was first isolated from a culture of Staphylococcus simulans by Schindler and Schuhardt in 1964. S. aureus cell walls contain high proportions of pentaglycin, making lysostaphin a highly effective agent against both actively growing and quiescent bacteria. Staphylococcal infections of both Staphylococcus aureus and Staphylococcus epidermidis continue to be a major issue in clinical settings, particularly those with implantable devices. Staphylococci cause a significant percentage of device infections, and like many other pathogens, rather than living as free planktonic cells within the host they have the ability to form a multilayered community of sessile bacteria cells known as a biofilm on implantable devices. Once a "Staphylococcal" biofilm has formed on an implanted medical device, it is difficult to disrupt due to its antibiotic resistance and protection against bacterial action.
