title: Cationic, anionic and neutral dyes: effects of photosensitizing properties and experimental conditions on the photodynamic inactivation of pathogenic bacteria.
abstract: The aim of this study was to evaluate the photobactericidal effect of four photosensitizers (PSs) with different structural and physico-photochemical properties, namely mesotetracationic porphyrin (T4MPyP), dianionic rose Bengal (RB), monocationic methylene blue (MB) and neutral red (NR). Their photokilling activity was tested in vitro on pathogenic bacteria such as Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) suspended in nutrient broth (NB) and in phosphate buffered saline (PBS) through following their influence on the PSs antimicrobial efficacy. Photodynamic inactivation (PDI) experiments were performed using visible light (L) and different PSs concentrations (20-70 μM). The ability of these PSs to mediate bacterial photodynamic inactivation was investigated as a function of type of PS and its concentrations, spectral and physico-chemical properties, bacterial strain, irradiation time and suspending medium. Indeed, they showed antibacterial effects against S. aureus and P. aeruginosa with significant difference in potency. Staphylococcus aureus suspended in NB showed 0.92 log units reduction in viable count in the presence of T4MPyP at 20 μM. Changing the suspending medium from NB to PBS, S. aureus was successfully photoinactivated by T4MPyP (20 μM) when suspended in PBS at least time exposure (10 and 30 min), followed by MB and RB.
authors: Laboratoire de Parasitologie des Eaux Usées et des Boues Résiduaires, Institut National de Recherche en Génie Rural Eaux et Forêts (INRGREF), Rue Hédi Karray, B.P. 10, 2080, Ariana, Tunis, Tunisia E-mail: sabbahisonia@yahoo.fr.
authors: Sonia
authors: S
authors: Sabbahi
authors: Laboratoire Sciences et Techniques de l'Eau, Institut National Agronomique de Tunis, Tunisia.
authors: Layla
authors: L
authors: Ben Ayed
authors: Laboratoire Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Tunisia.
authors: Abdellatif
authors: A
authors: Boudabbous
mesh_terms: D000818:Animals; D004396:Coloring Agents / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D008027:Light; D015394:Molecular Structure; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000528:radiation effects; D013211:Staphylococcus aureus / Q000187:drug effects / Q000528:radiation effects; D013997:Time Factors; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods
chemical_list: D004396:Coloring Agents; D017319:Photosensitizing Agents