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bioRxiv · 10.1101/227603

Annihilation of Methicillin-resistant Staphylococcus aureus via Photobleaching of Staphyloxanthin

Dong, P.-T.·Mohammad, H.·Wang, X.·Hui, J.·Li, J.·Liang, L.·Seleem, M. N.·Cheng, J.-X.
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Abstract

Given that the dearth of new antibiotic development loads an existential burden on successful infectious disease therapy1, health organizations are calling for alternative approaches to combat methicillin-resistant Staphylococcus aureus (MRSA) infections. Here, we report a drug-free photonic approach to eliminate MRSA through photobleaching of staphyloxanthin, an indispensable membrane-bound antioxidant of S. aureus2-5. The photobleaching process, uncovered through a transient absorption imaging study and quantitated by absorption spectroscopy and mass spectrometry, decomposes staphyloxanthin and sensitizes MRSA to reactive oxygen species attack. Consequently, staphyloxanthin bleaching by low-level blue light eradicates MRSA synergistically with external or internal reactive oxygen species. The effectiveness of this synergistic therapy is validated in MRSA culture, MRSA-infected macrophage cells, S. aureus biofilms, and a mouse wound infection model. Collectively, these findings highlight broad applications of staphyloxanthin photobleaching for treatment of MRSA infections.

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Dong, P.-T., Mohammad, H., Wang, X., Hui, J., Li, J., Liang, L., Seleem, M. N., Cheng, J.-X.. 2017-12-01. Annihilation of Methicillin-resistant Staphylococcus aureus via Photobleaching of Staphyloxanthin. https://doi.org/10.1101/227603

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