Motility 3 Flashcards
What level of Spo0A promotes biofilm formation?
High
Why does high levels of Spo0A promote biofilm formation?
Spo0A ends up repressing AbrB, which in turn represses EPS and TasA (biofilm genes) so more Spo0A means less AbrB, and so more biofilm
What are bacteria in biofilms surrounded by?
An adhesive matrix, the EPS
How do bacteria act as part of a community in a biofilm?
the cells express different genes and differentiate based on cell-cell signalling,
What can be different between different biofilms?
The bacteria involved, the matrix sugars and proteins, signalling pathways and physical forms
Two diff types of biofilm?
Mixed and Monoxenic
Most common type of biofilm?
Mixed
Mixed biofilm?
Several diff microbes, occurs naturally, environmentally important
Monoxenic biofilm?
Single microbial species, often considered artificial, often associated w/ infections
How are biofilms structured based on the bacteria they cotnain?
The chemical gradients–> i.e. bacteria at the bottom may be anaerobic due to low oxygen levels
Why are biofilm infections difficult to treat w/ antibiotics?
Lots of diff types of bacteria w/ diff characteristics
How are biofilm infections treated?
w/ large doses of antibiotics and for large periods of time
How does a biofilm benefit bacteria?
Traps and concentrates nutrients, defence, locates growth to favourable locations, prevents detachment in flowing systems
How does a biofilm help bacterial survival?
Antimicrobials cant penetrate into the matrix, resistance genes are expressed, persisters survive antibiotic treatment so the biofilm regrows
How to eradicate biofilms?
Multi drug therapy, anti microbial coating onto catheters, disrupting quorum sensing, blocking genes involved in biofilm formation
