In vitro bactericidal effect of Nd:YAG laser on Actinomyces israelii.
A bactericidal effect has been reported by the use of near-infrared laser light on both Gram-positive and Gram-negative bacteria. The aim of this study was to evaluate the effect of Nd:YAG laser on Actinomyces israelii, filamentous bacteria causing cervicofacial actinomycosis. Experiments were realized on bacterial cells in saline suspension or streaked on Mueller-Hinton (MH) agar plates with or without India ink. Laser application was performed in Eppendorf tubes with different powers and frequencies for 40 s; bacterial suspensions were then streaked on agar plates and incubated at 35 °C in proper conditions for 5 days before colony enumeration. A reduction of colony number variable from 60.13 to 100 % for powers of 2, 4, and 6 W at 25-50 Hz of frequency was observed in comparison with growth control. For agar plates, laser application was performed with different powers at 50 Hz for 60 s. A growth inhibition was observed after 5 days of incubation on MH plates with powers of 6 W and on MH-ink plates with all applied powers. This preliminary study showed a bactericidal effect caused by Nd:YAG laser application worthy to be evaluated in further experiments in vivo.
Faculté de Médécine et Chirurgie de Liège, Liege, Belgium.
Paolo
P
Vescovi
Stefania
S
Conti
Elisabetta
E
Merigo
Tecla
T
Ciociola
Luciano
L
Polonelli
Maddalena
M
Manfredi
Marco
M
Meleti
Carlo
C
Fornaini
Jean-Paul
JP
Rocca
S Amir
SA
Nammour
D000190:Actinomyces / Q000254:growth & development / Q000472:pathogenicity / Q000528:radiation effects*; D000197:Actinomycosis, Cervicofacial / Q000382:microbiology / Q000532:radiotherapy; D058491:Bacterial Load; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use; D028022:Low-Level Light Therapy / Q000379:methods