Pulsed photodynamic inactivation of gram-negative bacteria: in vitro study using methylene blue

Masafumi Nagasawa; Shunichi Sato; Satoko Kawauchi; Nariyoshi Shinomiya; Daizo Saito; Hiroshi Ashida; Minoru Obara

doi:10.1117/12.530817

14 June 2004 Pulsed photodynamic inactivation of gram-negative bacteria: in vitro study using methylene blue

Masafumi Nagasawa, Shunichi Sato, Satoko Kawauchi, Nariyoshi Shinomiya, Daizo Saito, Hiroshi Ashida, Minoru Obara

Proceedings Volume 5315, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XIII; (2004) https://doi.org/10.1117/12.530817
Event: Biomedical Optics 2004, 2004, San Jose, CA, United States

Abstract

Pulsed photodynamic effect on Ps.aeruginosa has been investigated in vitro with the use of methylene blue (MB) as a photosensitizer. Bacterial suspensions were illuminated with 665-nm, nanosecond light pulses under the various drug and light dose conditions. Bacterial survival fraction decreased with increasing the drug and light doses, while no significant bacterial cell death was observed when the bacteria were washed after incubation with the drug. These results suggest a two-step photo-bactericidal mechanism; the photodynamic effect first induces membrane damage through which MB molecules were translocated into the bacterial cytoplasm, and then caused bacterial cell death.

Citation Download Citation

Masafumi Nagasawa, Shunichi Sato, Satoko Kawauchi, Nariyoshi Shinomiya, Daizo Saito, Hiroshi Ashida, and Minoru Obara "Pulsed photodynamic inactivation of gram-negative bacteria: in vitro study using methylene blue", Proc. SPIE 5315, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XIII, (14 June 2004); https://doi.org/10.1117/12.530817

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