Photodynamic inactivation of pathogens causing infectious keratitis

Carole Simon; G. Wolf; M. Walther; K. Winkler; M. Finke; D. Hüttenberger; Markus Bischoff; B. Seitz; J. Cullum; H.-J. Foth

doi:10.1117/12.2037704

14 April 2014 Photodynamic inactivation of pathogens causing infectious keratitis

Carole Simon, G. Wolf, M. Walther, K. Winkler, M. Finke, D. Hüttenberger, Markus Bischoff, B. Seitz, J. Cullum, H.-J. Foth

Author Affiliations +

Proceedings Volume 8931, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXIII; 89310T (2014) https://doi.org/10.1117/12.2037704
Event: SPIE BiOS, 2014, San Francisco, California, United States

Abstract

The increasing prevalence of antibiotic resistance requires new approaches also for the treatment of infectious keratitis. Photodynamic Inactivation (PDI) using the photosensitizer (PS) Chlorin e6 (Ce6) was investigated as an alternative to antibiotic treatment. An in-vitro cornea model was established using porcine eyes. The uptake of Ce6 by bacteria and the diffusion of the PS in the individual layers of corneal tissue were investigated by fluorescence. After removal of the cornea’s epithelium Ce6-concentrations < 1 mM were sufficient to reach a penetration depth of 500 μm. Liquid cultures of microorganisms were irradiated using a specially constructed illumination chamber made of Spectralon(R) (reflectance: 99 %), which was equipped with high power light emitting diodes (λ = 670 nm). Clinical isolates of Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) from keratitis patients were tested in liquid culture against different concentrations of Ce6 (1 - 512 μM) using 10 minutes irradiation (E = 18 J/cm² ). This demonstrated that a complete inactivation of the pathogen strains were feasible whereby SA was slightly more susceptible than PA. 3909 mutants of the Keio collection of Escherichia coli (E.coli) were screened for potential resistance factors. The sensitive mutants can be grouped into three categories: transport mutants, mutants in lipopolysaccharide synthesis and mutants in the bacterial SOS-response. In conclusion PDI is seen as a promising therapy concept for infectious keratitis.

Citation Download Citation

Carole Simon, G. Wolf, M. Walther, K. Winkler, M. Finke, D. Hüttenberger, Markus Bischoff, B. Seitz, J. Cullum, and H.-J. Foth "Photodynamic inactivation of pathogens causing infectious keratitis", Proc. SPIE 8931, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXIII, 89310T (14 April 2014); https://doi.org/10.1117/12.2037704

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available