Biofilm

Question 1

What is a biofilm?

Answer 1

Breeding ground for antibiotic resistance as they change in genetic information and form a protective matrix consisting of sugar/ proteins and extracellular DNA.

Question 2

What are the three stages of the formation of a biofilm:

Answer 2

Attachment, growth and detachment.

Question 3

What type of bacteria form biofilms?

Answer 3

Gram positive

Question 4

What type of environment does a biofilm become a mushroom strcuture?

Answer 4

In a hydrodynamic environment.

In a flow cell - pseudomonas aeruginosa forms mushroom in lab.

Question 5

What type of environment does a column and canopy structure form?

Answer 5

In space, microgravity static environment.

Question 6

Are biofilms polymicrobial?

Answer 6

Yes, biofilms may contain only one or two species of bacteria but more commonly many species are formed (mixed biofilm)

Question 7

What is an example of a pioneer bacteria?

Answer 7

S. gordonii, S.oralis

Question 8

What are some surfaces in which microbial biofilms form?

Answer 8

Medical devices, inert surfaces to include water systems and pipework.

Question 9

Where does Vibrio Cholerae form biofilms before entry into a host?

Answer 9

In aquatic environments.

It also changes DNA before entering the host becoming more virulent.

Question 10

What pathogen forms biofilms in the airways of cystic fibrosis sufferers?

Answer 10

The opportunistic human pathogen Pseudomonas Aeruginosa - in the mucus of the lungs.

Question 11

What are three reasons why biofilms are important?

Answer 11

• survival
• remain in favourable niche
• close proximity to nutrients and other genetic material exchanges.

Question 12

How are biofilms able to TOLERATE antimicrobial substances?

Answer 12

• reduced penetration, biofilm structure
• bacteria grows slower
• different gene expression with enhanced expression of genes conferring tolerance to antimicrobial substances.

Question 13

How can bacteria influence other cells in biofilm community?

Answer 13

Through both chemical and physical interactions.

Question 14

What is the mechanism (3 - step) to the formation of the microbial biofilm?

Answer 14

• Attachment - planktonic cells to surface using pilli, flagella, adhesion proteins.
• Colonisation and cell-cell adhesion by the extracellular matrix (maturation)
• Dispersal: may be triggered by nutrient by nutrient availability or other environmental factors.

Question 15

What blocks Quorum sensing?

Answer 15

Furanone C30

Question 16

What are 3 of the strategies used for the control of biofilm formation?

Answer 16

• Inhibition of regulatory systems that control the formation trough low molecular weight molecules.
• DNASes
• Enzymes

Question 17

What can rapid dispersal of biofilms do?

Answer 17

This can be aggravating as it can quickly disseminate large numbers of bacteria into the bloodstream.

Question 18

How (3) are biofilms found in the lab?

Answer 18

• High throughput screening
• Metagenomic BioDiscovery ex: marine sponge
• Mining Microbe speak
• Immobilisation

Question 19

What is mining ‘microbe speak’?

Answer 19

This is when microbial compounds can be blocked in the biofilm in co-colonising pathogens.
Clinical isolates sensitive to small molecule analogues

Question 20

What is the most common signal bacteria use to contact eachother?

Answer 20

3-oxo-C12

Question 21

What does pseudomonas mainly use to communicate with each other?

Answer 21

HHQ - heptylquinoline

Question 22

What is the chemical form of communication used specifically by aeruginosa pseudomonas?

Answer 22

4-Alkylquinolones

Question 23

What is the inhaled/nebulised antibiotic used along with Furanone C30 to block Quorum Sensing?

Answer 23

Tobramycin