Antimicrobial photodynamic therapy treatment of chronic recurrent sinusitis biofilms

Abstract

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.

International Consensus Statement on Allergy and Rhinology: Rhinosinusitis

“…[344][345][346][347] Photodynamic therapy is a new and promising treatment that shows tremendous biofilm reductions in vitro, and preliminary tissue studies have not shown deleterious side effects. 348,349 Last, low-frequency ultrasound treatments also seem effective in reducing biofilms, also without observed side effects. 350 A promising new approach to understanding biofilms involves bitter taste receptors in the upper respiratory tract.…”

Silver Nanoparticles as Potential Antibacterial Agents

“…In particular, silver nanoparticles (AgNPs) have attracted much attention in the scientific field [11][12][13]. Silver has always been used against various diseases; in the past it found use as an antiseptic and antimicrobial against Gram-positive and Gram-negative bacteria [14][15][16] due to its low cytotoxicity [17]. AgNPs were considered, in recent years, particularly attractive for the production of a new class of antimicrobials [4,[18][19][20][21][22][23][24][25] opening up a completely new way to combat a wide range of bacterial pathogens.…”

“…Alteration of membrane [28,41,47] Listeria monocytogenes Morphological changes, separation of the cytoplasmic membrane from the cell wall, plasmolysis [47] Micrococcus luteus Alteration of membrane [28] Nitrifying bacteria inhibits respiratory activity [31] Pseudomonas aeruginosa Irreversible damage on bacterial cells; Alteration of membrane permeability and respiration [17,28,32,33,36,[41][42][43][44][48][49][50] Proteus mirabilis Alteration of cell wall and cytoplasm. [43,44] …”

Antimicrobial, Antimycobacterial and Antibiofi lm Properties of Couroupita guianensis Aubl. Fruit Extract

“…A signi�cant decrease in CFU/mL (>6 log 10 units) was achieved when 300 g/mL MB and a light dose of 60 J/cm 2 (diode laser, 664 nm) were used. e reduction was >7 log 10 units when 500 g/mL MB and two light doses of 55 J/cm 2 separated by a 5-minute break were used [64,65]. Meire et al observed a statistically signi�cant 1.9 log 10 reduction in the viable counts of E. faecalis bio�lms treated with 10 mg/mL MB and exposed to a so laser of an output power of 75 mW (660 nm) for 2 min [66].…”

“…e non-Candida pathogens T. mucoides and K. ohmeri were inactivated by APDT, with reductions of 0.85 log 10 and 0.84 log 10 , respectively [63]. Biel et al demonstrated that MB-mediated APDT is highly effective in the photoeradication of multispecies bacterial bio�lms (multidrug-resistant P. aeruginosa and MRSA) [64,65]. A signi�cant decrease in CFU/mL (>6 log 10 units) was achieved when 300 g/mL MB and a light dose of 60 J/cm 2 (diode laser, 664 nm) were used.…”