Singlet oxygen in Escherichia coli: New insights for antimicrobial photodynamic therapy.
Antimicrobial photodynamic therapy is an emerging treatment for bacterial infections that is becoming increasingly more attractive because of its effectiveness and unlikelihood of inducing bacterial resistance. However, there is limited knowledge about the localization of the photoactive drug in the bacteria and about the details of production of the main cytotoxic species, singlet oxygen. This article describes a combination of spectroscopic and time-resolved photophysical techniques that provide such information for a cationic porphyrin photosensitizer in gram-negative Escherichia coli bacteria. Our results reveal a double localization of the photosensitizer, inside (bound to the nucleic acids) and outside (bound to the cell wall) of the E. coli cells. Singlet oxygen is produced at both sites and is able to cross the cell wall.
Ragàs
Xavier
X
Institut Químic de Sarrià, Universitat Ramon Llull, 08017 Barcelona, Spain.
Agut
Montserrat
M
Nonell
Santi
S
D000890:Anti-Infective Agents / Q000378:metabolism / Q000494:pharmacology; D003903:Deuterium / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism; D004927:Escherichia coli Infections / Q000188:drug therapy*; D015200:Fluoroimmunoassay; D008826:Microbial Sensitivity Tests; D008954:Models, Biological; D010778:Photochemotherapy / Q000379:methods* / Q000639:trends; D017319:Photosensitizing Agents / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D026082:Singlet Oxygen / Q000378:metabolism* / Q000494:pharmacology*; D012997:Solvents / Q000494:pharmacology
D000890:Anti-Infective Agents; D017319:Photosensitizing Agents; D012997:Solvents; D026082:Singlet Oxygen; D012710:Serum Albumin, Bovine; D003903:Deuterium