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

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, which are difficult to treat. While antibiotics are largely inefficient in limiting biofilm formation and expansion, antimicrobial peptides (AMPs) are emerging as alternative anti-biofilm 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 and both viability of bacteria contained in the biofilm as well as biomass of the biofilm were quantified using resazurin and crystal violet labelling, respectively. Antibiofilm effect of TAT-RasGAP317-326 was compared to a selection of classical antibiotics and AMPs. Results We observe that TAT-RasGAP317-326 inhibits biofilm formation at concentrations equivalent or two times superior to the minimal inhibitory concentration 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. Conclusions 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.