Abstract
Purpose :
To investigate the influence of blue light emission on pathogenic filamentous fungi Fusarium solani (F. solani) spores obtained from fungal keratitis patients.
Methods :
Pathogenic filamentous fungi were obtained from four patients with fungal keratitis (two with single and two with repeated fungal infection) and a standard F. solani strain was also imported. All five strains were identified based on DNA sequencing as F. solani. Fungal spores were isolated and irradiated by a light-emitting diode (LED) device with peak wavelength of 458nm at 5W/m2 or maintained in darkness for 0 to 48 hours. Pictures of fungi were taken by inverted microscope at 0, 12, 24, 36 and 48 hours. The treated spores from these five time points were then cultured on Sabouraud's Dextrose Agar plates at 29 °C for 36 hours before determination of colony formation as a measure of viability.
Results :
Significantly increased number of spores was observed with blue light emission group compared to dark condition in all five fungi samples. Patient-originated F. solani strains presented enhanced growth activities than standard fungi, and there was no significantly difference between single and repeated infective groups. After 36 hours plate culture, the number of clones was significantly higher in patient-originated samples in comparison with standard F. solani strain, although identical number of spores was coated. Blue light significantly enhanced the number of clones after 24 or more hours of emission in all samples, and the extent of elevation was more remarkable in four patient-originated F. solani strains. In darkness group, the number of clones began to shrink from 36-hour time point and significantly decreased after 48 hours incubation. However, consistent number of clones was recorded at 24, 36 and 48 hours time points in all five samples from blue light emission group.
Conclusions :
Blue light emission could possibly promoted spore formation and consequently improved viability in standard and patient-originated F. solani strains. F. solani samples isolated from fungal keratitis patients presented enhanced growth activities and more remarkable response to blue light against standard strain.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.