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Published on: April 23, 2019
Inactivation of Candida albicans following exposure to 624-nanometer light from a supraluminous diode array
J Stephen Guffey1, William Payne, Leslie James
1J. 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.
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 Data:
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.

