Recognition of the fact that bacterial biofilm may play a role in the pathogenesis of disease has led to an increased focus on identifying diseases that may be biofilm-related. Biofilm infections are typically chronic in nature, as biofilm-residing bacteria can be resilient to both the immune system, antibiotics, and other treatments. This is a comprehensive review describing biofilm diseases in the auditory, the cardiovascular, the digestive, the integumentary, the reproductive, the respiratory, and the urinary system. In most cases reviewed, the biofilms were identified through various imaging technics, in addition to other study approaches. The current knowledge on how biofilm may contribute to the pathogenesis of disease indicates a number of different mechanisms. This spans from biofilm being a mere reservoir of pathogenic bacteria, to playing a more active role, e.g., by contributing to inflammation. Observations also indicate that biofilm does not exclusively occur extracellularly, but may also be formed inside living cells. Furthermore, the presence of biofilm may contribute to development of cancer. In conclusion, this review shows that biofilm is part of many, probably most chronic infections. This is important knowledge for development of effective treatment strategies for such infections.

The aim of the study was to evaluate the antibacterial efficacy of Lugol's solution, acetic acid, and boric acid against Staphylococcus aureus biofilm. The efficacy of Lugol's solution 1%, 0.1%, and 0.05%, acetic acid 5% or boric acid 4.7% for treatment of Staphylococcus aureus biofilm in vitro was tested using 30 clinical strains. Susceptibility in the planktonic state was assessed by disk diffusion test. Antiseptic effect on bacteria in biofilm was evaluated by using a Biofilm-oriented antiseptic test (BOAT) based on metabolic activity, a biofilm bactericidal test based on culturing of surviving bacteria and confocal laser scanning microscopy combined with LIVE/DEAD staining. In the planktonic state, all tested S. aureus strains were susceptible to Lugol's solution and acetic acid, while 27 out of 30 tested strains were susceptible to boric acid. In biofilm the metabolic activity was significantly reduced following exposure to Lugol's solution and 5% acetic acid, while boric acid exposure led to no significant changes in metabolic activities. In biofilm, biocidal activity was observed for Lugol's solution 1% (30/30), 0.1% (30/30), and 0.05% (26/30). Acetic acid and boric acid showed no bactericidal activity in this test. Confocal laser scanning microscopy, assessed in 4/30 strains, revealed significantly fewer viable biofilm bacteria with Lugol's solution (1% p < 0.001, 0.1% p = 0.001 or 0.05% p = 0.001), acetic acid 5% for 10 min (p = 0.001) or 30 min (p = 0.015), but not for acetic acid for 1 min or boric acid. Lugol's solution 1.0% and 0.1% effectively eradicated S. aureus in biofilm and could be an alternative to conventional topical antibiotics where S. aureus biofilm is suspected such as external otitis, pharyngitis and wounds.

Background: Increasing antimicrobial resistance to antibiotics is a substantial health threat. Bioactive glass S53P4 (BAG) has an antimicrobial effect that can reduce the use of antibiotics. The aim of this study was to evaluate the antimicrobial efficacy of BAG in vitro on staphylococci in biofilm and in planktonic form. Secondary aims were to investigate whether supernatant fluid primed from BAG retains the antibacterial capacity and if ciprofloxacin enhances the effect. Methods: BAG-S53P4 granules, <45 µm, primed in tryptic soy broth (TSB) were investigated with granules present in TSB (100 mg/mL) and after removal of granules (100, 200, and 400 mg/mL). The efficacy of BAG to eradicate Staphylococcus aureus biofilm in vitro was tested using 10 different clinical strains and 1 reference strain in three test systems: the biofilm-oriented antiseptic test based on metabolic activity, the biofilm bactericidal test based on culturing surviving bacteria, and confocal laser scanning microscopy (CLSM) combined with LIVE/DEAD staining. Results: Exposure to 48 h primed BAG granules (100 mg/mL) produced bactericidal effects in 11/11 strains (p = 0.001), and CLSM showed reduction of viable bacteria in biofilm (p = 0.001). Supernatant primed 14 days, 400 mg/mL, reduced metabolic activity (p < 0.001), showed bactericidal effects for 11/11 strains (p = 0.001), and CLSM showed fewer viable bacteria (p = 0.001). The supernatant primed for 48 h, or in concentrations lower than 400 mg/mL at 14 days, did not completely eradicate biofilm. Conclusion: Direct exposure to BAG granules, or primed supernatant fluid, effectively eradicated S. aureus in biofilm. The anti-biofilm effect is time- and concentration-dependent. When BAG had reached its full antimicrobial effect, ciprofloxacin had no additional effect.

The study aimed to evaluate the antibacterial efficacy of Lugol's solution 5% and Gentian violet 1% against methicillin‐resistant Staphylococcus aureus (MRSA) biofilm in vivo. The bactericidal efficacy for treatment of MRSA‐biofilm skin wound infection was tested in a murine model. Luciferase‐tagged S. aureus Xen31, a MRSA‐strain derived from S. aureus ATCC‐3359130, was used for infection. Wounds were made in the skin of mice and infected with MRSA. The mice were treated with Lugol's solution and Gentian violet. Application of the antimicrobial agents started 24 hours post infection and was repeated daily for five‐days. The antimicrobial effect on the biofilm bacteria was evaluated by measuring bioluminescence from MRSA daily for seven‐days. Lugol's solution and Gentian violet showed a significant reduction in luminescent signals from the first assessment day to all subsequent days (P < .001). Lugol's solution and Gentian violet effectively eradicated MRSA in biofilm in vivo and could be alternatives or in addition to topical antibiotics when MRSA‐biofilm wound infection is suspected.