Biofilms Flashcards
1
Q
Define Biofilm
A
- morphologically heterogeneous & multi-layered
- surface-attached communities of bacteria encases in an extracellular matrix
- able to attach to surfaces & each other
2
Q
Describe the Biofilm Phenotype
A
- slower growth rate
- increased antibiotic resistance
- chemotaxis
- motility
3
Q
How do polysaccharides determine biofilm architecture ?
A
- by protecting cells from the host defences and anti microbial
4
Q
What are some applications of Biofilms
A
- purify water in water treatment plants
- break down often toxic chemicals
- produce biomolecules, including drugs
5
Q
What are some examples of where biofilms can be found ?
A
- on humans
- plants
- animals
6
Q
What are the key components of a biofilms matrix ?
A
- glycolipids
- living cells
- dead debris
- proteins
- polysaccharides
- lipids
-surfactants
7
Q
Define Adherence Factors
A
Many pathogenic bacteria colonise mucosal sites by using fimbriae to adhere to cells
8
Q
Describe antibiotic resistance in biofilms
A
- centre of a biofilm the bacteria have a greater antibiotic resistance
- this is due to ;
- poor antibiotic penetration
- adaptive stress responses
9
Q
Define Persister cells
A
- occur stochastically
- mechanism for population survival
- forgo rapid growth and remain slow growing
10
Q
What is Quorum Sensing ?
A
- process of bacterial communication involving producing, releasing, detecting and responding to small hormone-like molecules of diffusible molecules called ‘autoinducers’
11
Q
Describe Enterococcus Faecalis
A
- high levels of antibiotic resistance
- can cause life-threatening infections
- E. faecalis can form biofilms on dental root canals, urethral catheters & stents
12
Q
What is the most commonly biofim found in humans ?
A
- dental plaque
13
Q
Describe Biofilm Based Wound Care
A
- debridement
- selective biocides
- antibiofilm agents
- antibiotics
14
Q
What are the primary gram positive colonisers ?
A
- Streptococcus sanguis
- Streptococcus mutans
15
Q
What primary gram negative colonisers ?
A
- Fusobacterium nucleatum
- Prevotella intermedia
