title: Antimicrobial activity of merocyanine 540: a photosensitizing dye.
abstract: The antimicrobial activity of merocyanine 540 (MC 540), a photosensitizing dye previously used to purge malignant cells from autologous bone marrow grafts, was evaluated against a panel of Gram-positive and Gram-negative bacteria and Candida albicans in the presence and absence of light. In the absence of light, MC 540 demonstrated no antibacterial activity against any of the organisms tested. When combined with increasing intervals of photoillumination, growth inhibition was observed with all Gram-positive organisms tested except Mycobacterium fortuitum. Photosensitizing growth inhibition was also observed with Moraxella catarrhalis but not with any other Gram-negative bacilli including members of the Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophila, or Burkhoderia cepacia. These results suggested that differences in cell wall structure confer resistance to the photodamaging effects of the dye. MC 540 exhibited no antimicrobial activity against C. albicans in the presence or absence of light.
authors.affiliation: Department of Pathology, Henry Ford Health System, Detroit, Michigan, USA.
authors.forename: W M
authors.initials: WM
authors.lastname: Dunne
authors.forename: W A
authors.initials: WA
authors.lastname: Slater
mesh_terms: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects* / Q000254:growth & development; D015169:Colony Count, Microbial; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000254:growth & development; D008027:Light; D008826:Microbial Sensitivity Tests; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011744:Pyrimidinones / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D017319:Photosensitizing Agents; D011744:Pyrimidinones; C003954:merocyanine dye