The antimicrobial peptide TAT-RasGAP317-326 inhibits the formation and expansion of bacterial biofilms in vitro

Abstract

ABSTRACT: Objectives: Biofilms are structured aggregates of bacteria embedded in a self-produced matrix that develop in diverse ecological niches. Pathogenic bacteria can form biofilms on surfaces and in tissues, causing nosocomial and chronic infections that are difficult to treat. While antibiotics are largely inefficient in limiting biofilm formation and expansion, antimicrobial peptides (AMPs) are emerging as alternative antibiofilm treatments. In this study, we explore the effect of the newly described AMP TAT-RasGAP317-326 on Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus biofilms. Methods: Efficiency of TAT-RasGAP317-326 on biofilms was tested in vitro. Both viability of bacteria contained in the biofilm as well as biomass of the biofilm were quantified using resazurin and crystal violet staining, respectively. The antibiofilm effect of TAT-RasGAP317-326 was compared with a selection of classical antibiotics and AMPs. Results: We observe that TAT-RasGAP317-326 inhibits biofilm formation at concentrations equivalent or two times greater than the minimum inhibitory concentration (MIC) of planktonic bacteria. Moreover, TAT-RasGAP317-326 limits the expansion of A. baumannii and P. aeruginosa established biofilms at twice the concentration inhibiting biofilm formation. Conclusion: These results underscore the potential use of TAT-RasGAP317-326 against biofilms and encourage further studies in the development of AMPs to treat biofilm-related infections.

Keywords

• Biofilm
• Antimicrobial peptide
• Acinetobacter baumannii
• Pseudomonas aeruginosa
• Staphylococcus aureus
• TAT-RasGAP317-326