TY - JOUR
T1 - Influence of blue light on Streptococcus mutans re-organization in biofilm
AU - Chebath-Taub, Daniella
AU - Steinberg, Doron
AU - Featherstone, John D.B.
AU - Feuerstein, Osnat
N1 - Funding Information:
Supported in part by the US–Israel Binational Foundation (2005094).
PY - 2012/11/5
Y1 - 2012/11/5
N2 - Our aim was to examine the viability and structure of new biofilm formed by Streptococcus mutans that was previously exposed to blue light. S. mutans bacteria were grown to form a mature biofilm, that was exposed to blue light (wavelengths, 400-500 nm) for 1-10 min (equivalent to 68-680 J/cm2). Biofilm was dispersed by sonication, and then the suspended bacteria were grown to re-organize as a new biofilm. Biofilm formation after 2, 4, and 6 h, was examined by viable counts and by confocal laser scanning microscopy using live/dead bacterial staining. A significant decrease in bacterial viability was found in the 6 h biofilms formed by bacteria that had been previously exposed to blue light for 7 or 10 min. Confocal microscopy images showed a decrease in the live/dead bacterial ratio after 3-10 min of light exposures. Dead bacteria were mainly at the outer layers of the biofilm. Exposure of S. mutans in biofilm to blue light affected the re-formation of a new biofilm, showing an increase in the amount of dead bacteria. This phenomenon suggests that blue light has a delayed antibacterial effect, although it does not interfere with bacterial capability to reform an initial biofilm.
AB - Our aim was to examine the viability and structure of new biofilm formed by Streptococcus mutans that was previously exposed to blue light. S. mutans bacteria were grown to form a mature biofilm, that was exposed to blue light (wavelengths, 400-500 nm) for 1-10 min (equivalent to 68-680 J/cm2). Biofilm was dispersed by sonication, and then the suspended bacteria were grown to re-organize as a new biofilm. Biofilm formation after 2, 4, and 6 h, was examined by viable counts and by confocal laser scanning microscopy using live/dead bacterial staining. A significant decrease in bacterial viability was found in the 6 h biofilms formed by bacteria that had been previously exposed to blue light for 7 or 10 min. Confocal microscopy images showed a decrease in the live/dead bacterial ratio after 3-10 min of light exposures. Dead bacteria were mainly at the outer layers of the biofilm. Exposure of S. mutans in biofilm to blue light affected the re-formation of a new biofilm, showing an increase in the amount of dead bacteria. This phenomenon suggests that blue light has a delayed antibacterial effect, although it does not interfere with bacterial capability to reform an initial biofilm.
KW - Antibacterial
KW - Oral biofilm
KW - Plaque
KW - Visible light
UR - http://www.scopus.com/inward/record.url?scp=84865975060&partnerID=8YFLogxK
U2 - 10.1016/j.jphotobiol.2012.08.004
DO - 10.1016/j.jphotobiol.2012.08.004
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C2 - 22982208
AN - SCOPUS:84865975060
SN - 1011-1344
VL - 116
SP - 75
EP - 78
JO - Journal of Photochemistry and Photobiology B: Biology
JF - Journal of Photochemistry and Photobiology B: Biology
ER -