Red/Orange Autofluorescence in Selected Candida Strains Exposed to 405 nm Laser Light

• Main Authors: Rafał Wiench (Author), Dariusz Paliga (Author), Anna Mertas (Author), Elżbieta Bobela (Author), Anna Kuśka-Kiełbratowska (Author), Sonia Bordin-Aykroyd (Author), Aleksandra Kawczyk-Krupka (Author), Kinga Grzech-Leśniak (Author), Monika Lukomska-Szymanska (Author), Edward Lynch (Author), Dariusz Skaba (Author)
• Format: Book
• Published: MDPI AG, 2024-02-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/dj12030048; 2304-6767
• Keywords: yeast; autofluorescence; oral candidiasis; porphyrins; protoporphyrin; fluorophore; Dentistry; RK1-715
• Source: Dentistry Journal, Vol 12, Iss 3, p 48 (2024)

Background: <i>Candida albicans</i> and similar species are significant pathogens in immunocompromised and hospitalized individuals, known for mucosal colonization and bloodstream/organ invasion. Many pathogenic <i>fungi,</i> including these species, exhibit autofluorescence (R/OF) under specific light conditions, a feature crucial for their detection. Aim: We investigated the use of a 405 nm diode laser for the direct observation of red/orange autofluorescence of <i>Candida</i> spp., common in the oral cavity, exploring its potential in health screenings. Methods: This study utilized cultures of <i>Candida</i> spp. on Sabouraud dextrose agar with Qdot 655 and 685 for fluorescence benchmarking, illuminated using a 405 nm diode laser (continuous wave, power 250 mW, 0.0425 J/cm² fluence, 0.0014 W/cm² power density). Images were captured using a yellow-filter camera at set intervals (48 to 144 h). Visual and computational analyses evaluated the R/OF in terms of presence, intensity, coloration, and intra-colony variation. Results: Most <i>Candida strains</i> displayed red/orange autofluorescence at all observation times, characterized by varied coloration and intra-colony distribution. Initially, there was an increase in R/OF intensity, which then stabilized in the later stages of observation. Conclusions: The majority of the <i>Candida strains</i> tested are capable of emitting R/OF under 405 nm laser light. This finding opens up new possibilities for integrating R/OF detection into routine dental screenings for <i>Candida</i> spp.