Inactivation of Candida albicans following exposure to 624-nanometer light from a supraluminous diode array.
OBJECTIVE
To determine the potential for visible light (405 or 624 nm) to produce an inhibitory effect on Candida albicans. In addition, the study sought to evaluate a series of doses in terms of their respective inhibiting capabilities.


BACKGROUND
The authors have studied the effect of blue light on Staphylococcus aureus and found that a bactericidal outcome can be obtained with low doses of blue light.


METHODS
Candida albicans was tested because of its common appearance in human skin and mucous membrane infections. The organism was treated in vitro with 405-nm (blue) and with 624-nm (red) light emitted from a supraluminous diode array. Doses of 3, 9, 15, 30, and 60 J/cm(2) were used. Colony counts were performed and compared with untreated controls using Student t tests and 1-way analysis of variance with Tukey post hoc analysis.


RESULTS
The results revealed no inhibition produced by 405 nm on C albicans (F4,20 = 0.901; P = .482). However, 624 nm did inhibit growth of C albicans at 3, 9, and 30 J/cm(2) (F4,20 = 6.064; P = .002).


CONCLUSIONS
Appropriate doses of 624-nm light from a supraluminous diode array can inhibit the growth of C albicans in vitro. Three, 9, and 30 J/cm(2) are all effective dose levels.
J. Stephen Guffey, PT, EdD, is an Associate Professor of Physical Therapy; William Payne, MS, ASCP(MT), is an Assistant Professor of Clinical Laboratory Science; Leslie James, BS, is a Doctor of Physical Therapy Student; Zhuoyuan Qian, BS, is a Doctor of Physical Therapy Student; and Carly Dodson is a Clinical Laboratory Science Student; all at Arkansas State University, Jonesboro, Arkansas. Dr Guffey has disclosed that he is a consultant for Dynatronics Corporation. The coauthors have disclosed that they have no financial relationships related to this article.
J Stephen
JS
Guffey
William
W
Payne
Leslie
L
James
Zhuoyuan
Z
Qian
Carly
C
Dodson
D002176:Candida albicans / Q000254:growth & development* / Q000528:radiation effects*; D002177:Candidiasis / Q000175:diagnosis / Q000532:radiotherapy; D015169:Colony Count, Microbial; D003881:Dermatomycoses / Q000175:diagnosis / Q000532:radiotherapy; D006801:Humans; D066298:In Vitro Techniques; D054023:Lasers, Semiconductor / Q000627:therapeutic use; D010789:Phototherapy / Q000379:methods*; D011829:Radiation Dosage; D012680:Sensitivity and Specificity