Universität Innsbruck

Seminar of the Department of Microbiology

Fungal Photosensitizers for Photodynamic Antimicrobial Therapy

Johannes Fiala, PhD candidate - University of Innsbruck, Department of Pharmacognosy (Inst. Pharmacy)

02.12.2021, 11:00 - Join online (Meeting-ID: 679 622 0429 / Password: 8R39Sa)



The overuse and inapt application of antimicrobial drugs have driven the rapid emergence of multidrugresistant bacteria, as well as human pathogenic fungi. Antimicrobial drug resistance is considered a serious threat to human health. Photodynamic antimicrobial chemotherapy (PACT), based on the synergistic effect of light and a chromophore, succeeds in killing multidrug-resistant microorganisms (MOs), causing non-specific multi-target damage through reactive oxygen species (ROS) [1]. To our current knowledge, PACT is considered unlikely to promote resistance, making this approach an interesting treatment option in times of antibiotic crisis and “superbugs” like Candida auris. Established photosensitizers (PSs) for PACT are often based on dyes or porphyrin structures. Our goal is to discover novel, more active structures aside from well-known scaffolds. We established a high-throughput screening (HTS) method, based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST), allowing for examination and comparison of potential PSs under different wavelengths, light doses, and preincubation times [2]. Utilizing the ancient evolutionary battle of survival between fungi and bacteria we are screening Ascomycota, Basidiomycota and lichen for novel PSs, following a bioactivity guided approach.

[1] S. Marasini, L.G. Leanse, T. Dai, Can microorganisms develop resistance against light based anti-infective agents?, Advanced drug delivery reviews (2021).

[2] J. Fiala, H. Schöbel, P. Vrabl, D. Dietrich, F. Hammerle, D.J. Artmann, R. Stärz, U. Peintner, B. Siewert, A New High-Throughput-Screening-Assay for Photoantimicrobials Based on EUCAST Revealed Unknown Photoantimicrobials in Cortinariaceae, Front Microbiol 12 (2021) 703544.