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 of infections 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 against in a manner similar to the human peptide LL-37. LL-37 exhibits strong antimicrobial activity against as well as biofilm disruption and synergy with certain antibiotics posing the question whether gp28 could act similarly.

METHODS

Antibacterial activity of gp28 against was 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 against was measured using a modified time-kill assay at sublethal concentrations.

RESULTS

Gp28 inhibits planktonic growth, with a minimum inhibitory concentration of 109 μg mL and disrupts established biofilms. We demonstrate that gp28 increases the susceptibility of to tobramycin.

CONCLUSIONS

Gp28 demonstrates potential for development as a putative therapeutic agent against a clinically resistant strain either alone or in combination with the frontline antibiotic tobramycin.