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What are biofilms
- complex groups of many species growing on a solid surface
- genetic diversity, metabolic diversity, metabolic interdependence
- contain an extracellular matrix- glycocalyx- some sort of polysaccharide binds species together
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Formation of Biofilms
- require coloinzing species which is followed by growth and diversity (matrix formation)
- these colonizing organisms stick to surfaces, start to colonize and gain other to help them
- form on submerged surfaces (wet surfaces)
- cell division and recuitment: metabolic transition: quorum sensing- individual cell knows its surrounded by a bunch of other cells so it changes its metabolic activity and what it does
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Examples of biofilms
- Dental plaque
- Prosthetics
- Resident foreign materials: pacemakers, catheters
- Wounds
- Primary environmental surfaces:Rocks, ship hulls, submarine equipment
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Steps of Biofilms (dental plaque)
- 1. Attachment- A few species attach- do not produce a gylcocaylyx
- 2. Initial colonization- Form a gylcocaylyx
- 3. Secondary colonization- Gets bigger
- 4. Mature Biofilms- Very complex architecture, aerobic organisms on top, anaerobic in the middle, circulation of liquid all around the biofilm
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Quorum Sensing
- Genetic and metabolic changes
- dependent on cell density
- pigment production
- drug resistance
- Physical- growth in a matrix prevents drugs from getting there
- Metabolic- drug resistance is produced as a result of cell density
- Toxin formation
- Matrix production
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