Combined Use of Bacteriophage K and a Novel Bacteriophage To Reduce Staphylococcus aureus Biofilm Formation

Abstract

ABSTRACTBiofilms are major causes of impairment of wound healing and patient morbidity. One of the most common and aggressive wound pathogens isStaphylococcus aureus, displaying a large repertoire of virulence factors and commonly reduced susceptibility to antibiotics, such as the spread of methicillin-resistantS. aureus(MRSA). Bacteriophages are obligate parasites of bacteria. They multiply intracellularly and lyse their bacterial host, releasing their progeny. We isolated a novel phage, DRA88, which has a broad host range amongS. aureusbacteria. Morphologically, the phage belongs to theMyoviridaefamily and comprises a large double-stranded DNA (dsDNA) genome of 141,907 bp. DRA88 was mixed with phage K to produce a high-titer mixture that showed strong lytic activity against a wide range ofS. aureusisolates, including representatives of the major international MRSA clones and coagulase-negativeStaphylococcus. Its efficacy was assessed both in planktonic cultures and when treating established biofilms produced by three different biofilm-producingS. aureusisolates. A significant reduction of biofilm biomass over 48 h of treatment was recorded in all cases. The phage mixture may form the basis of an effective treatment for infections caused byS. aureusbiofilms.