Phage-Encoded Antimicrobial Peptide gp28 Demonstrates LL-37-Like Antimicrobial Activity Against Multidrug-Resistant.

BACKGROUND: () is a gram-negative bacterial pathogen commonly associated with nosocomial infections. Treatment ofinfections is notoriously difficult due to biofilm formation and antibiotic resistance. Antimicrobial peptides (AMPs) are thought to be promising new antimicrobials. Gp28, a phage-derived AMP, is a novel class of characterized phage AMPs with activity againstin a manner similar to the human peptide LL-37. LL-37 exhibits strong antimicrobial activity againstas well as biofilm disruption and synergy with certain antibiotics posing the question whether gp28 could act similarly. METHODS: Antibacterial activity of gp28 againstwas established using growth inhibition assays, with minimum inhibitory concentration calculated. Biofilm disruption was assessed using crystal violet staining and scanning electron microscopy. Combined treatment of gp28 with tobramycin againstwas measured using a modified time-kill assay at sublethal concentrations. RESULTS: Gp28 inhibitsplanktonic growth, with a minimum inhibitory concentration of 109 μg mLand disrupts established biofilms. We demonstrate that gp28 increases the susceptibility ofto tobramycin. CONCLUSIONS: Gp28 demonstrates potential for development as a putative therapeutic agent against a clinically resistantstrain either alone or in combination with the frontline antibiotic tobramycin.