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Photo-activated porphyrin in combination with antibiotics: Therapies against Staphylococci ☆

Paper ID Volume ID Publish Year Pages File Format Full-Text
30181 44463 2013 9 PDF Available
Title
Photo-activated porphyrin in combination with antibiotics: Therapies against Staphylococci ☆
Abstract

•Meso-Tetra (4-aminophenyl) porphine (TAPP) is a light, dose, and time-dependent antimicrobial.•Antibiotics + illuminated TAPP are at least additive for S. aureus, S. epidermidis, MRSA, and E. coli.•TAPP can be used for several cycles before losing phototoxicity through photodegradation.

Staphylococcal infections have become difficult to treat due to antibiotic insensitivity and resistance. Antimicrobial combination therapies may minimize acquisition of resistance and photodynamic therapy is an attractive candidate for these combinations. In this manuscript, we explore combined use of antibiotics and meso-tetra (4-aminophenyl) porphine (TAPP), a cationic porphyrin, for treatment of Staphylococcus aureus contamination. We characterize the antimicrobial activity of photoactivated TAPP and show that activity is largely lost in the presence of a radical scavenger. Importantly, TAPP can be reactivated with continued, albeit attenuated, antibacterial activity. We then show that the antimicrobial activity of illuminated TAPP is additive with chloramphenicol and tobramycin for S. aureus and Escherichia coli, and synergistic for MRSA and Staphylococcus epidermidis. Chloramphenicol + methylene blue, another photosensitizer, also show additivity against S. aureus. In contrast, ceftriaxone and vancomycin do not strongly augment the low level effects of TAPP against S. aureus. Eukaryotic cells exhibit a dose-dependent toxicity with illuminated TAPP. Our results suggest that even sub-minimum inhibitory concentrations of photo-activated TAPP could be used to boost the activity of waning antibiotics. This may play an important role in treatments reliant on antibiotic controlled release systems where augmentation with photo-active agents could extend their efficacy.

Keywords
Porphyrins; TAPP; Antibiotics; Staphylococci; E. coli; Osteoblasts
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 129, 5 December 2013, Pages 27–35
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us