Photodynamic inactivation of Gram-negative bacteria: Problems and possible solutions

Malik, Zvi; Ladan, Hava; Nitzan, Yeshayahu

doi:10.1016/1011-1344(92)85104-3

Cited by 308 publications

(246 citation statements)

References 15 publications

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“…Despite a lower 1 O 2 production, RB displayed the highest incorporation rate and antibacterial activity among the three photosensitizers tested [16]. The relative porous layer of peptidoglycan surrounding the cytoplasmic membrane of Gram-positive bacteria was shown to allow the penetration of neutral or anionic PS's [17].…”

Section: Introductionmentioning

confidence: 94%

Rose bengal uptake by E. faecalis and F. nucleatum and light-mediated antibacterial activity measured by flow cytometry

Manoil

Filieri

Schrenzel

et al. 2016

Journal of Photochemistry and Photobiology B: Biology

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Rose bengal uptake by E. faecalis and F. nucleatum and light-mediated antibacterial activity measured by flow cytometry Antibacterial photodynamic therapy (aPDT) using rose bengal (RB) and blue-light kills bacteria through the production of reactive oxygen derivates. However, the interaction mechanism of RB with bacterial cells remains unclear. This study investigated the uptake efficiency and the antibacterial activity of blue light-activated RB against Enterococcus faecalis and Fusobacterium nucleatum. Spectrophotometry and epifluorescence microscopy were used to evaluate binding of RB to bacteria. The antibacterial activity of RB after various irradiation times was assessed by flow cytometry in combination with cell sorting. Uptake of RB increased in a concentration dependent manner in both strains although E. faecalis displayed higher uptake values. RB appeared to bind specific sites located at the cellular poles of E. faecalis and at regular intervals along F. nucleatum. Blue-light irradiation of samples incubated with RB significantly reduced bacterial viability. After incubation with 10 μM RB and 240 s irradiation, only 0.01% (± 0.01%) of E. faecalis cells and 0.03% (±0.03%) of F. nucleatum survived after treatment. This study indicated that RB can bind to E. faecalis and F. nucleatum in a sufficient amount to elicit effective aPDT. Epifluorescence microscopy showed a yet-unreported property of RB binding to bacterial membranes. Flow cytometry allowed the detection of bacteria with damaged membranes that were unable to form colonies on agars after cell sorting.

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Section: Introductionmentioning

confidence: 94%

Rose bengal uptake by E. faecalis and F. nucleatum and light-mediated antibacterial activity measured by flow cytometry

Manoil

Filieri

Schrenzel

et al. 2016

Journal of Photochemistry and Photobiology B: Biology

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“…The Gram-negative bacteria E. coli is pathogenic to humans and other animals. Due to the previously reported higher resistance of Gram-negative species 27,28 the PS concentration and light fluences were increased when compared to the Gram-positive S. aureus. Fig.…”

Section: Photodynamic Inactivation Of Microorganismsmentioning

confidence: 99%

Photobiological characteristics of chlorophyll a derivatives as microbial PDT agents

Uliana

Pires

Pratavieira

et al. 2014

Photochem Photobiol Sci

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a Chlorin-e6 (chl-e6) and a hydrogenated derivative (chl-e6H) were semi-synthesized, and their photophysical properties and photodynamic activity against Escherichia coli, Staphylococcus aureus and Candida albicans evaluated. Methyl pheophorbide-a (Mepheo-a) was obtained from S. maxima using methanolic extraction with acid catalysis (CH 3 OH-H 2 SO 4 ). Chlorin-e6 was prepared from Mepheo-a by basic hydrolysis with H 2 O-acetone and NaOH. Hydrogenated Chlorin-e6 was synthesized by a similar procedure starting from the hydrogenated methyl pheophorbide-a (Mepheo-aH). Photophysical studies were performed in order to determine the singlet oxygen quantum yield of chl-e6H which is higher than that of chl-e6. The microorganism inactivation of chl-e6 and chl-e6H was investigated at two concentrations and three fluence levels. Both chl-e6 and chl-e6H showed microorganism inactivation against Gram-positive bacteria and a fungus.

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“…Gram-negative bacterial cells are relatively resistant to these compounds [14]. The high susceptibility of Gram-positive bacteria and fungi was explained by their physiology as a relatively porous layer of peptidoglycan and lipoteichoic acid, or beta-glucan and chitin, respectively, surrounds their cytoplasmic membrane and both these structures allow noncationic PSs to cross [14,15]. Gram-negative bacteria are less prone to take up exogenous compounds due to the extra outer membrane and the permeability barrier imparted by lipopolysaccharides [16].…”

Section: Antimicrobial Efficacy Of Pdt: the Photosensitizersmentioning

confidence: 99%

Can Nanotechnology Shine a New Light on Antimicrobial Photodynamic Therapies?

Bloise¹,

Minzioni²,

Imbriani³

et al. 2017

Photomedicine - Advances in Clinical Practice

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Recent developments in light-controlled therapies (e.g., photodynamic and photothermal therapies) provide promising strategies to prevent and suppress bacterial infections, which are a leading cause of morbidity and mortality. Antibacterial photodynamic therapy (aPDT) has drawn increasing attention from the scientific society for its potential to kill multidrug-resistant pathogenic bacteria and for its low tendency to induce drug resistance. In this chapter, we summarize the mechanism of action of aPDT, the photosensitizers, as well the current developments in terms of treating Gram-positive and Gram-negative bacteria. The chapter also describes the recent progress relating to photomedicine for preventing bacterial infections and biofilm formation. We focus on the laser device used in aPDT and on the light-treatment parameters that may have a strong impact on the results of aPDT experiments. In the last part of this chapter, we survey on the various nanoparticles delivering photoactive molecules, and photoactive-nanoparticles that can potentially enhance the antimicrobial action of aPDT.

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Photodynamic inactivation of Gram-negative bacteria: Problems and possible solutions

Cited by 308 publications

References 15 publications

Rose bengal uptake by E. faecalis and F. nucleatum and light-mediated antibacterial activity measured by flow cytometry

Rose bengal uptake by E. faecalis and F. nucleatum and light-mediated antibacterial activity measured by flow cytometry

Photobiological characteristics of chlorophyll a derivatives as microbial PDT agents

Can Nanotechnology Shine a New Light on Antimicrobial Photodynamic Therapies?

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