Background
Biofilm: mischief maker in an armored cocoon
The facilitating factors and environment
A. Host factors
B. Microbial factors
C. Environmental factors
The clinical significance of biofilms in wounds
A. Recalcitrant wound healing
B. Antimicrobial tolerance and resistance
Diffusion barrier
Nutrition limitation
General stress response
Quorum sensing (QS)
Biofilm-specific phenotype
Host immune response resistance
Host immune responses to biofilm constituents
Host cell response to pathogenic biofilms
Tools for the detection of biofilms
Therapeutic options
Anti-biofilm strategies | Mechanism of action | Examples | |
---|---|---|---|
(A) Inhibition of biofilm initiation | |||
1 | Alteration of hydrophobicity, surface charge | Hyaluronic acid, Hydrogel membranes, fluorinated silica/titanium coatings | |
2 | Altering the exterior of biomaterial | Ion coatings, biocides, antibiotics | |
(B) Inhibition of biofilm establishment/Biofilm dispersals | |||
1 | Disruption of the biofilm mode of existence | Meta-bromo-thiolactone, FS3, Daptomycin | |
2 | Anti-Quorum sensing peptides [96] | Attenuate quorum sensing | RNA III-inhibiting peptide |
(C) Biofilm eradicators | |||
1 | Destroy extracellular polymeric substances (EPS) [97] | Disruption of protective EPS to expose bacteria to antibacterial agents | Deoxyribonuclease I (DNase I), Dispersin B, Alginate lyase |
2 | Nanoparticles [98] | Creating artificial channels in EPS | Laser-induced nanobubbles, Magnetic nanoparticles |
3 | Disruption of the cell membrane, inhibition of enzymatic activity | LL-37, Oritavancin | |
4 | Disruption of the bacterial membrane–cell lysis | Mono-/bis-/tris-QACs, XF-70, XF-73 | |
5 | Cell lysis, disruption of electron transport chain, inhibition of bacterial enzymes | Glycerol monolaurate, Docosahexaenoic acid, Eicosapentaenoic acid | |
6 | Anti-biofilm mediators | PhilBB-PF 7A | |
7 | Variable | 1. Plant extracts: Green tea, Dandasa, fresh garlic extract (FGE) 2. Honey: Sidr, Manuka 3. Essential oils: Cumin, Cinnamon oil | |
8 | Broad-spectrum antibiotics | Vancomycin-D-octaarginine (V-r8), Pentobra | |
9 | Adjuncts to enhance the sensitivity of conventional antibiotics | 1. Electrochemical treatment: damage bacterial membrane 2. Cryogenic freezing |
Therapies targeting bacteria
Bacteriophage therapy
Bacteriophages are viruses and the natural predators of bacteria. Their ability to negate the protective biofilm stems from these proposed mechanisms: