Erythrosine-Mediated Photodynamic Inactivation of Bacteria and Yeast Using Green Light-Emitting Diode Light
EN-SHENG, KE1, SAMI NAZZAL2, YU-HANG TSENG3, CHUEH-PIN CHEN3 AND TSUIMIN TSAI3*
1. TaipeiMedicalUniversity – ShuangHoHospital, New Taipei City, Taiwan, R.O.C.
2. Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, MonroeLA, U.S.A.
3. Graduate Institute of Biomedical Materials and Tissue Engineering, College of Oral Medicine,
Taipei Medical University, Taipei, Taiwan, R.O.C.
(Received: February 6, 2012; Accepted: June 26, 2012)
ABSTRACT
Erythrosine, also known as FD&C Red No. 3, is a synthetic dye that has been used for food coloring and dental plaque detection. The objective of this study was to evaluate erythrosine as a viable photosensitizer in photodynamic inactivation (PDI) of bacteria and yeast. Cells were treated with erythrosine with or without acetic acid in the presence and absence of light. Erythrosine in the absence of light did not show any activity against the microorganisms. When treated with light, erythrosine was efficient in eradicating non-adherent (planktonic) Gram (+) bacteria and yeast. However, Gram (-) bacteria were less responsive to PDI. Addition of acetic acid was found to enhance the activity of erythrosine and significantly lower the survival of Gram (-) bacteria. This study demonstrated the potential applications of erythrosine in PDI and the potentiating effects of acetic acid.
Key words: erythrosine, acetic acid, photodynamic inactivation (PDI), bacteria, yeast, biofilm