title: Photosensitizing activity of hematoporphyrin on Staphylococcus aureus cells.
abstract: The photosensitizing action of hematoporphyrin (Hp) on two Staphylococcus aureus strains was investigated to determine if the photoprocess induces in vivo damage in DNA in addition to that occurring at the level of the cytoplasmic membrane. The results obtained demonstrate that the photokilling is dependent on the Hp dose even though the two strains, having a similar Hp-binding capacity, show different levels of photosensitivity. The electrophoretic analysis of cytoplasmic membrane proteins and DNA (chromosomal and plasmidial) suggests that the membrane represents the primary target of the photoprocess, while the DNA, that is damaged both in vivo and in vitro only at relatively long irradiation time, might be a secondary target. Moreover, the photoprocess results in mutagenesis for Salmonella typhimurium tester strains. This information is particularly important in view of the potential use of photodynamic therapy for the treatment of microbial infections.
authors.affiliation: Istituto di Microbiologia, Via A. Gabelli 63, 35121, Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Bertoloni
authors.forename: F M
authors.initials: FM
authors.lastname: Lauro
authors.forename: G
authors.initials: G
authors.lastname: Cortella
authors.forename: M
authors.initials: M
authors.lastname: Merchat
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002470:Cell Survival; D004249:DNA Damage; D004269:DNA, Bacterial / Q000032:analysis / Q000187:drug effects / Q000528:radiation effects; D004586:Electrophoresis; D006415:Hematoporphyrins / Q000494:pharmacology*; D008027:Light; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000528:radiation effects; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D006415:Hematoporphyrins; D017319:Photosensitizing Agents