title: The effect of antimicrobial photodynamic therapy with radachlorin® on Staphylococcus aureus and Escherichia coli: an in vitro study.
abstract: BACKGROUND
  The aim of this study is the evaluation of the effect of Antimicrobial Photodynamic Therapy with Radachlorin on Staphylococcus aureus and Escherichia coli. New windows are open in the antimicrobial field so-call Photodynamic therapy that incorporates a nonpoisonous photosensitizer (PS) with innocuous special wavelength photons to excite the PS.
  
  
  METHODS
  Two strains of bacteria used in this study were Methicillin resistant Staphylococcus aureus (ATCC 33591; PTCC 1764) and Escherichia coli (ATCC 25922; PTCC1399). Concentrations of 0.2 ml of Radachlorin® were applied on 0.2 ml of bacterial suspensions and placed in a 48-well microtiter plate. The following groups were used: (I) L- PS- (no laser, no photosensitizer), (II) L-PS+ (treated only with PS), (III) L+ PS- (treated only with laser) and (IV) L+ PS+ (treated with laser and PS: photodynamic therapy group). Aliquots of bacterial suspensions were sensitized with Radachlorin® for 15 minutes in the dark at room temperature and then bacterial suspensions in group III and IV were irradiated with 210 mW (power density) and 12 J/cm2 (energy density) on continuous mode.
  
  
  RESULTS
  This study showed that photodynamic therapy reduces 0.14 log 10 in E.Coli (group IV) and there were significant differences for group IV (P<0.01). Photodynamic therapy in S.Aureus showed 6.28 log 10 colony count reduction (group IV) and there were highly significant differences in Photodynamic therapy group (P<0.0001).
  
  
  CONCLUSIONS
  Radachlorin® have bactericidal effect on S.aureus (6.28 log 10) and bacteriostaticeffect on E.coli (0.14 log 10).
authors: Department of Dentistry, AJA University of Medical Sciences, Tehran, Iran.
authors: Reza
authors: R
authors: Fekrazad
authors: Periodontic Department, Faculty of Dentistry, Tehran University of Medical sciences, Tehran, Iran.
authors: Hadi
authors: H
authors: Zare
authors: Operative dentistry Department, Faculty of Dentistry, Tehran University of Medical sciences, Tehran, Iran.
authors: Sara
authors: S
authors: Mohammadi Sepahvand
authors: Department of Dentistry, AJA University of Medical Sciences, Tehran, Iran.
authors: Parisa
authors: P
authors: Morsali
keywords: escherichia coli; photodynamic therapy; staphylococcus aureus
references: Am J Infect Control. 2012 Jun;40(5):416-20
references: 21943832
references: J Hosp Infect. 2011 Dec;79(4):364-5
references: 21864936
references: J Vet Pharmacol Ther. 2006 Dec;29(6):501-11
references: 17083454
references: J Antimicrob Chemother. 2009 Jul;64(1):59-61
references: 19411679
references: J Photochem Photobiol B. 1990 May;5(3-4):281-93
references: 2115912
references: Lasers Med Sci. 2010 Sep;25(5):705-10
references: 20414708
references: Pol J Microbiol. 2005;54(4):305-10
references: 16599302
references: Theranostics. 2011 Apr 06;1:230-9
references: 21562630
references: J Antimicrob Chemother. 2002 Jun;49(6):941-51
references: 12039886
references: J Dent (Tehran). 2011 Spring;8(2):48-54
references: 21998808
references: Khirurgiia (Mosk). 2001;(4):10-3
references: 11490483
references: Proc Natl Acad Sci U S A. 2006 Apr 4;103(14):5620-5
references: 16565219
references: Photochem Photobiol. 1984 Jun;39(6):811-6
references: 6431458
references: Sichuan Da Xue Xue Bao Yi Xue Ban. 2011 Sep;42(5):661-5
references: 22007494
references: Photodiagnosis Photodyn Ther. 2004 Dec;1(4):279-93
references: 25048432
references: Lasers Med Sci. 2009 Mar;24(2):162-6
references: 18239960
references: Photodiagnosis Photodyn Ther. 2011 Sep;8(3):249-53
references: 21864798
references: Mikrobiologiia. 1991 May-Jun;60(3):507-11
references: 1745143
references: Clin Microbiol Infect. 2005 Jul;11 Suppl 4:1-16
references: 15953019
references: Antimicrob Agents Chemother. 2004 Jun;48(6):2173-8
references: 15155218
references: J Infect Chemother. 2007 Apr;13(2):87-91
references: 17458675
references: Antimicrob Agents Chemother. 2008 Sep;52(9):3202-9
references: 18474586