Meso-substituted cationic porphyrins as efficient photosensitizers of gram-positive and gram-negative bacteria

✍ Scribed by Michèle Merchat; Giulio Bertolini; Paolo Giacomini; Angeles Villaneuva; Giulio Jori

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 395 KB
• Volume: 32
• Category: Article
• ISSN: 1011-1344
• DOI: 10.1016/1011-1344(95)07147-4

✦ Synopsis

Previous studies on the photosensitization of bacterial cells with different neutral or negatively charged porphyrins and phthalocyanines have demonstrated that, although Gram-positive bacteria are efficiently photoinactivated, Gram-negative bacteria become photosensitive only after modification of the permeability of their outer membrane. The results described in this paper show that two meso-substituted cationic porphyrins, namely tetra(4N-methyl-pyridyl)porphine tetraiodide and tetra(4N,N,N-trimethyl-anilinium)porphine, efficiently photosensitize the inactivation of Gram-negative bacteria, such as Vibrio anguillarum and Escherichia coli. A negatively charged meso-substituted porphyrin, tetra(4-sulphonatophenyl)porphine, has no appreciable photosensitizing activity towards Gram-negative bacteria, although all three porphyrins exhibit a similar subcellular distribution pattern, being mainly localized in the protoplasts or spheroplasts. Moreover, the three porphyrins show similar efficiency in the photoinactivation of the Gram-positive bacterium Entorecoccus seriolicida.