1. Effects of Photodynamic Inactivation on the Growth and Antifungal Susceptibility of Rhizopus oryzae
- Author
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Jing Tang, Zhaoyang Liu, Lujuan Gao, and Yi Sun
- Subjects
Azoles ,0301 basic medicine ,Posaconazole ,Antifungal Agents ,Light ,Itraconazole ,Veterinary (miscellaneous) ,medicine.medical_treatment ,030106 microbiology ,Colony Count, Microbial ,Rhizopus oryzae ,Photodynamic therapy ,Microbial Sensitivity Tests ,Pharmacology ,Applied Microbiology and Biotechnology ,Microbiology ,030207 dermatology & venereal diseases ,03 medical and health sciences ,Minimum inhibitory concentration ,chemistry.chemical_compound ,0302 clinical medicine ,Amphotericin B ,medicine ,Humans ,Microbial Viability ,Photosensitizing Agents ,biology ,Chemistry ,biology.organism_classification ,Antimicrobial ,Methylene Blue ,Growth inhibition ,Agronomy and Crop Science ,Rhizopus ,medicine.drug - Abstract
Mucormycosis is an aggressive and high-mortality opportunistic fungal infection, especially in immunocompromised patients. Conventional antifungals or surgery showed a limited effect on this disease. The antimicrobial photodynamic therapy (aPDT) has been proven to be a promising therapeutic choice against multiple pathogenic fungi. We evaluated the effect of aPDT by using methylene blue (MB) combined with a light emitting diode (LED) on the viability of Rhizopus oryzae, as well as the antifungal susceptibility after aPDT treatment in vitro. A total of six strains were included in this study; MB (8, 16, and 32 μg/ml) was chosen for the photosensitizer, and a light source of LED (635 ± 10 nm, 12 J/cm2) device was used to active it. aPDT with MB (32 μg/ml) and LED was highly effective in cell growth inhibition and exhibited colony-forming unit reductions of up to 4.3log10. The minimal inhibitory concentration ranges of itraconazole, posaconazole, and amphotericin B decreased from > 32 μg/ml to 4–8 μg/ml, 8–16 μg/ml to 0.5–2 μg/ml, and 2–4 μg/ml to 0.25–0.5 μg/ml, respectively, after pre-treatment with MB (8 μg/ml) and LED. In conclusion, aPDT with MB and LED was a promising therapeutic option against R. oryzae infections alone or combined with antifungal agents. However, further investigation is needed to determine the potential for clinic therapy and to elucidate the underlying mechanism.
- Published
- 2019