Antimicrobial and anti-biofilm effect of a novel BODIPY photosensitizer against Pseudomonas aeruginosa PAO1

Abstract

Photodynamic therapy (PDT) combines the use of organic dyes (photosensitizers, PSs) and visible light in order to elicit a photo-oxidative stress which causes bacterial death. GD11, a recently synthesized PS belonging to the boron-dipyrromethene (BODIPY) class, was demonstrated to be efficient against planktonic cultures of Pseudomonas aeruginosa, causing a 7 log unit reduction of viable cells when administered at 2.5 μM. The effectiveness of GD11 against P. aeruginosa biofilms grown in flow-cells and microtiter trays was also demonstrated. Confocal laser scanning microscopy of flow-cell-grown biofilms suggests that the treatment has a biocidal effect against bacterial biofilm cells.

Keywords:

• BODIPY
• photodynamic treatment
• Pseudomonas aeruginosa

Acknowledgements

The authors thank Fabrizio Pogliana for collaboration in the experimental work. This research was funded by the University of Insubria (Fondo di Ateneo per la Ricerca), and by a grant from the Danish Council for Independent Research.