RESEARCH ARTICLE A Bioengineered Nisin Derivative to Control Biofilms of Staphylococcus pseudintermedius

Antibiotic resistance and the shortage of novel antimicrobials are among the biggest chal-lenges facing society. One of the major factors contributing to resistance is the use of front-line clinical antibiotics in veterinary practice. In order to properly manage dwindling antibiotic resources, we must identify antimicrobials that are specifically targeted to veteri-nary applications. Nisin is a member of the lantibiotic family of antimicrobial peptides that exhibit potent antibacterial activity against many gram-positive bacteria, including human and animal pathogens such as Staphylococcus, Bacillus, Listeria, and Clostridium. Al-though not currently used in human medicine, nisin is already employed commercially as an anti-mastitis product in the veterinary field. Recently we have used bioengineering strate-gies to enhance the activity of nisin against several high profile targets, including multi-drug resistant clinical pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) and also against staphylococci and strepto-cocci associated with bovine mastitis. However, newly emerging pathogens such as methi-cillin resistant Staphylococcus pseudintermedius (MRSP) pose a significant threat in terms of veterinary health and as a reservoir for antibiotic resistance determinants. In this study we created a nisin derivative with enhanced antimicrobial activity against S. pseudinterme-dius. In addition, the novel nisin derivative exhibits an enhanced ability to impair biofilm for-mation and to reduce the density of established biofilms. The activities of this peptide represent a significant improvement over that of the wild-type nisin peptide and merit further investigation with a view to their use to treat S. pseudintermedius infections