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

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-RasGAP on Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus biofilms.

METHODS

Efficiency of TAT-RasGAP 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-RasGAP was compared with a selection of classical antibiotics and AMPs.

RESULTS

We observe that TAT-RasGAP inhibits biofilm formation at concentrations equivalent or two times greater than the minimum inhibitory concentration (MIC) of planktonic bacteria. Moreover, TAT-RasGAP 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-RasGAP against biofilms and encourage further studies in the development of AMPs to treat biofilm-related infections.