Advantage and Core Benefit
- High Versatility Independent of Specific Antibiotics: Confirmed effective with multiple antibiotics, such as kanamycin and gentamicin, allowing for broad applications.
- Potential for Developing Novel Formulations Based on Mechanisms: Experiments using Safranin as a reagent have confirmed efficacy, enabling the screening of other candidate compounds utilizing an established evaluation system.
- Applicability to a Wide Range of Bacteria: Efficacy has been demonstrated in Shewanella (a model bacterium) and Pseudomonas aeruginosa (a pathogenic bacterium), suggesting potential applications across various bacterial species.
Background and Technology
Biofilms inhibit antibiotic penetration and reduce bactericidal effects due to the polysaccharide matrix formed by bacteria. Traditional antibiotic treatments struggle to eliminate biofilms. Biofilm control strategies include inhibition and dispersion techniques using D-amino acids and nanoparticles, as well as methods leveraging hydrophobicity changes induced by metal ions. However, these methods are limited by bacterial species specificity, making them less effective for broad biofilm control.
This technology employs redox molecules (e.g., safranin) to activate electron transfer within biofilms, promoting bacterial metabolism and enhancing antibiotic sensitivity.
Key Mechanisms
- Promotion of Electron Transfer: Redox molecules such as safranin donate electrons, altering the NADH/NAD⁺ balance in bacteria and activating metabolism.
- Enhancement of Drug Sensitivity: Reactivating dormant bacteria increases antibiotic penetration.
This technology is expected to be applied in biofilm control for infectious disease treatment and hygiene management products in combination with antibiotics.
Data
- Shewanella oneidensis biofilms were formed on medium containing Safranin and cultured for 24 hours, followed by an additional 24-hour culture in medium containing various concentrations of kanamycin. CFU measurements showed enhanced kanamycin sensitivity in bacteria treated with 10µM safranin.
- In electron transfer pathway-deficient strains (lacking OmcA-containing cytochromes), safranin addition showed no effect under similar test conditions, suggesting that antibiotic sensitivity enhancement is due to electron transfer activation rather than safranin toxicity.
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Patent & Publication
Patent Pending (Unpublished)
Researcher
Dr. Yoshihide Tokuno (University of Tsukuba, Faculty of Life and Environmental Sciences)
Expectations
We seek collaborative research with pharmaceutical and hygiene product development companies to further elucidate the mechanism and develop formulations. The Laboratory at the University of Tsukuba possesses the following evaluation systems for the practical application of this technology.
- Visualization system for NADH/NAD⁺ ratio within biofilms
- Evaluation system for electron transfer within colonies
- Assessment using biofilm model bacterium (Shewanella oneidensis)
Project No.WL-05092