Photodynamic inactivation to prevent and disrupt Staphylococcus aureus biofilm under different media conditions

Abstract

Objective The goal of this work was to investigate the photodynamic activity of 5,10,15,20‐tetrakis[4‐(3‐N,N‐dimethylaminopropoxy)phenyl]chlorin (TAPC) and zinc(II) 2,9,16,23‐tetrakis[4‐(N‐methylpyridyloxy)]phthalocyanine iodide (ZnPPc4+) as photosensitizers to inactivate Staphylococcus aureus biofilms and prevent their formations in different culture media. Methods We incubated S aureus biofilms in different culture media: tryptic soy (TS), nutrient (N), Müeller Hinton (MH) broth, TS with glucose 2 and 5% (w/v) with 5 μM ZnPPc4+ or TAPC and irradiated with visible light (350‐800 nm). Photodynamic inactivation (PDI) was determined by count of colony forming units (CFU) and crystal violet method. Furthermore, we studied PDI effect on biofilm development in TS broth. Finally, we examined the effects of PDI on the structure of S aureus biofilm. Results Greater inactivation was achieved, using TAPC or ZnPPc4+, when S aureus biofilm was grown in N or MH broths rather than in TS. Besides, glucose addition to the medium decreases the ability to develop biofilm and increase the photoinactivation capacity. Prevention of 3 log biofilm developments was obtained when S aureus cultures were treated with TAPC (10 μM) and 108 J/cm2 in TS broth and the number of CFU was counted after 24 hours. Moreover, microscopy studies demonstrated modifications in biofilm architecture. Conclusions These results indicate that TAPC and ZnPPc4+ may be promising photosensitizers for photodynamic inactivation of S aureus biofilms or to prevent their formation.

Photoactive antimicrobial coating based on a PEDOT-fullerene C60 polymeric dyad

“…2.12 Scanning electron microscopy of S. aureus biolm on PEDOT-C 60 S. aureus biolm on PEDOT-C 60 samples were prepared as previously reported. 47,48 The samples were then covered with gold and examined with a scanning electron microscope. SEM images were obtained with a eld emission scanning electron microscope FE-SEM, Sigma Zeiss (LAMARX facilities).…”

New Perspectives on Old and New Therapies of Staphylococcal Skin Infections: The Role of Biofilm Targeting in Wound Healing

“…This suggests that in the most difficult cases, APDT may be a valid treatment option. There are promising studies in the literature demonstrating in vitro anti-biofilm staphylococcal action of APDT with various photosensitisers and blue light, [ 171 , 172 , 173 , 174 , 175 , 176 , 177 , 178 , 179 ] but which are lacking in vivo histological evaluation of wound healing.…”

Antimicrobial Photodynamic Therapy with Chlorin e6 Is Bactericidal against Biofilms of the Primary Human Otopathogens

“…We observed that a single aPDT treatment significantly decreased bacterial viability by >99.9% for all three bacterial strains. It is well established that biofilm-associated bacteria are typically less sensitive to aPDT than planktonic cells ( 17 , 18 ). Thus, it was not unexpected that PS concentration and irradiation times had to be increased to achieve similar photoinactivation rates within the biofilms.…”