Effect of Ca+ on the photobactericidal efficacy of methylene blue and toluidine blue against gram-negative bacteria and the dye affinity for lipopolysaccharides

Усачева, М. Н.; Teichert, Matthew C.; Sievert, Chet; Biel, Merrill A.

doi:10.1002/lsm.20400

Cited by 36 publications

(31 citation statements)

References 24 publications

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“…The present study continues our previous investigations of the interaction between the phenothiazine dyes, methylene blue (MB) and toluidine blue (TB), and gram-negative bacteria to clarify the differences in the photobactericidal efficacies of these dyes [1][2][3]. MB and TB are commercial phenothiazine dyes widely accepted in medical practice.…”

Section: Introductionsupporting

confidence: 61%

“…Therefore, the initial interaction between TB and LPS could be responsible for the greater total bacterial photodamage with TB as compared to MB. This is supported by our work examining the inhibiting effect of Ca 2þ , a competitor of TB and MB for the LPS interaction, on the photobactericidal efficacy of the dyes [3]. The stronger the complex between TB and LPS, the greater inhibiting effect of CaCl 2 will be on the photokilling of bacteria with TB.…”

Section: Introductionmentioning

confidence: 52%

“…Figure 5 shows that the MB system transformations differed significantly from that of LPS. Specifically the MB bacterial spectrum had two [3]. isosbestic points at 592 and 680 nm; both the monomer and dimer peaks were suppressed with increasing bacterial concentrations.…”

Section: Discussionmentioning

confidence: 97%

“…The fact that PaA is responsible for the fluorescence of P. aeruginosa cells induced by visible light makes it possible to associate the observed changes in the P. aeruginosa fluorescence with the interactions between the PaA system and the dyes. Moreover, the selection of P. aeruginosa for the present investigation was also motivated by the very significant effect of CaCl 2 to inhibit the interaction of TB and MB with pseudomonal LPS and bacterial photodamage induced by these dyes [2,3].…”

Section: Introductionmentioning

confidence: 99%

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Interaction of the photobactericides methylene blue and toluidine blue with a fluorophore in Pseudomonas aeruginosa cells

Усачева¹,

Teichert²,

Usachev

et al. 2008

Lasers Surg Med

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Background and Objectives: The difference in photobactericidal efficacy between methylene blue (MB) and toluidine blue (TB) may be explained by their involvement with proteins, lipopolysaccharides (LPS), and siderophores and siderophore-receptor protein complexes on the bacterial outer membrane. This study aims to determine if this is the case by using the fluorescence given off by a pseudomonal siderophore named pyoverdin. Study Design/Materials and Methods: Confocal laser scanning microscopy was used to observe the fluorescence of Pseudomonas aeruginosa cells excited at 488 nm in the presence of increasing dye concentrations. Results: Cellular fluorescence at 522 nm progressively decreased with increasing dye concentrations. The SternVolmer constants for cellular fluorescence quenching with the dyes were compared to the association constants for dyes complexed with LPS. The quenching of cellular fluorescence was associated with the formation of a ground-state complex between the dyes and pyoverdin-FpvA protein system. MB readily complexed with this system, whereas TB complexed more strongly with LPS. Conclusion: The different affinities of the dyes for both pyoverdin-protein and LPS will affect the contributions of the dyes' interactions with these biopolymers to the overall bacterial photodamage.

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Section: Introductionsupporting

confidence: 61%

Section: Introductionmentioning

confidence: 52%

Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

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Interaction of the photobactericides methylene blue and toluidine blue with a fluorophore in Pseudomonas aeruginosa cells

Усачева¹,

Teichert²,

Usachev

et al. 2008

Lasers Surg Med

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“…In order to compensate for potential photobleaching of TB under the influence of microorganisms, the photosensitizer chlorin e6 (Ce6; C 34 H 36 N 4 O 6 ) was also tested (66). Ce6 is a chlorophyll a-based second-generation photosensitizing agent, which is derived from the green seawater alga Chlorella (Chlorella ellipsoidea) (67).…”

Section: Discussionmentioning

confidence: 99%

Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A

Karygianni

Ruf

Follo

et al. 2014

Appl Environ Microbiol

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Antimicrobial photodynamic therapy (APDT) has gained increased attention as an alternative treatment approach in various medical fields. However, the effect of APDT using visible light plus water-filtered infrared A (VIS ؉ wIRA) on oral biofilms remains unexplored. For this purpose, initial and mature oral biofilms were obtained in situ; six healthy subjects wore individual upper jaw acrylic devices with bovine enamel slabs attached to their proximal sites for 2 h or 3 days. The biofilms were incubated with 100 g ml ؊1 toluidine blue O (TB) or chlorin e6 (Ce6) and irradiated with VIS ؉ wIRA with an energy density of 200 mW cm ؊2 for 5 min. After cultivation, the CFU of half of the treated biofilm samples were quantified, whereas following live/dead staining, the other half of the samples were monitored by confocal laser scanning microscopy (CLSM). TB-and Ce6-mediated APDT yielded a significant decrease of up to 3.8 and 5.7 log 10 CFU for initial and mature oral biofilms, respectively. Quantification of the stained photoinactivated microorganisms confirmed these results. Overall, CLSM revealed the diffusion of the tested photosensitizers into the deepest biofilm layers after exposure to APDT. In particular, Ce6-aided APDT presented elevated permeability and higher effectiveness in eradicating 89.62% of biofilm bacteria compared to TB-aided APDT (82.25%) after 3 days. In conclusion, antimicrobial photoinactivation using VIS ؉ wIRA proved highly potent in eradicating oral biofilms. Since APDT excludes the development of microbial resistance, it could supplement the pharmaceutical treatment of periodontitis or peri-implantitis.

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Antimicrobial photodynamic therapy treatment of chronic recurrent sinusitis biofilms

Biel

Sievert²,

Усачева³

et al. 2011

Int Forum Allergy Rhinol

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Background Chronic recurrent sinusitis (CRS) is an inflammatory disease of the facial sinuses and nasal passages that is defined as lasting longer than 12 weeks or occurring more than 4 times per year with symptoms usually lasting more than 20 days. The National Institute for Health Statistics estimates that CRS is one of the most common chronic conditions in the United States affecting an estimated 37 million Americans. The potential etiologies of CRS include bacteria, viruses, allergies, fungi, superantigens and microbial biofilms. In clinical practice there is a significant subpopulation of patients with CRS who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy and prolonged antibiotic therapy. The reason for treatment failure is thought to be related to the destruction of the sinus mucociliary defense by the chronic sinus infection resulting in the development of secondary antibiotic resistant microbial colonization of the sinuses and biofilm formation. Antimicrobial photodynamic therapy (aPDT) is a non-antibiotic broad spectrum antimicrobial treatment that has been demonstrated to eradicate antibiotic resistant bacteria and biofilms. Objective The objective of this study was to demonstrate the effectiveness of a non-invasive aPDT treatment method of eradicating antibiotic resistant biofilms/microorganisms known to cause CRS in an in vitro model. Methods Antibiotic resistant planktonic bacteria and fungi and polymicrobial biofilms of Pseudomonas aerugenosa and MRSA were grown on silastic sheets and treated with a methylene blue photosensitizer and 670nm non-thermal activating light. Cultures of the planktonic micoroorganisms and biofilms were obtained before and after light treatment to determine efficacy of planktonic baciteria and biofilm reduction. Results The in vitro CRS planktonic microorganism and biofilm study demonstrated that aPDT reduced the CRS polymicrobial biofilm by >99.9% after a single treatment. Conclusions aPDT can effectively treat CRS polymicrobial antibiotic resistant bacteria, fungi and biofilms both in vivo. Human clinical studies are currently planned to assess the safety and efficacy of this treatment for CRS.

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Effect of Ca+ on the photobactericidal efficacy of methylene blue and toluidine blue against gram-negative bacteria and the dye affinity for lipopolysaccharides

Abstract: CaCl(2) inhibits bacterial photokilling by binding with LPS, as well as other anionic polymers including outer membrane proteins. LPS is chiefly involved in TB-mediated photokilling, whereas outer membrane proteins probably are more involved in MB-mediated photokilling.

Cited by 36 publications

References 24 publications

Interaction of the photobactericides methylene blue and toluidine blue with a fluorophore in Pseudomonas aeruginosa cells

Interaction of the photobactericides methylene blue and toluidine blue with a fluorophore in Pseudomonas aeruginosa cells

Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A

Antimicrobial photodynamic therapy treatment of chronic recurrent sinusitis biofilms

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