glycol-substituted Zn(II) phthalocyanine

Methicillin resistant Staphylococcus aureus infections are increasing, especially in intensive care units. A new method for photodynamic inactivation (PDI) generates reactive oxygen species by photosensitization to kill bacteria. We investigated the PDI effect of tetraethylene glycol-substituted Zn(II) phthalocyanine (TEG-P) on S. aureus strains including two standards (ATCC 25923 and ATCC 43400) and 20 clinically isolated methicillin sensitive and 20 methicillin resistance strains. We also investigated three treated groups: 650 nm laser only, TEG-P only and TEG-P + laser, plus one control group. Treatments included 0.5, 1, 2, 4, 8, 16, 32 mu g/ml concentrations of TEG-P. No suppression of bacterial growth was observed in the control, laser only and TEG-P only groups whether or not S. aureus was methicillin resistant. Bacterial growth was suppressed by 85% using 8 mu g/ml TEG-P and completely suppressed by 32 mu g/ml TEG-P in the TEG-P + laser group. A combination of TEG-P + laser treatment may be an alternative to conventional antibiotics for routine treatment of S. aureus infections, although further investigation of the effect at the tissue level is required.C1 [Mete, Ergun; Ergin, Cagri] Pamukkale Univ, Fac Med, Dept Med Microbiol, TR-20160 Denizli, Turkey.[Kabay, Nilgun] Pamukkale Univ, Fac Technol, Dept Biomed Engn, Denizli, Turkey.[Dumoulin, Fabienne] Acibadem Mehmet Ali Aydinlar Univ, Fac Engn, Dept Med Engn, Istanbul, Turkey.[Ahsen, Vefa; Kostakoglu, Sinem Tuncel] Gebze Tech Univ, Fac Basic Sci, Dept Chem, Kocaeli, Turkey