General Flashcards
Class?
Gammaproteobacteria
Genus?
Psuedomonas
Gram?
Negative
Motile?
Yes
Shape?
Rod shaped
Primary habitat?
Primary habitat is the environment (soil, water, vegetation) with a preference to moist environment
How is it able to grow in low nutrient availability?
Can use ammonium and carbon dioxide as nitrogen and carbon sources
Can grow at a broad temperature range?
20-42 oC
Can grow anaerobically when it uses what as an electron acceptor?
Either nitrate or nitrite
What type of pathogen is it?
It is an opportunistic pathogen
Most infections are?
Nosocomial
Can form biofilms on medical equipment including?
Intravenous vein catheters
Urinary catheters
Ventilation devices
Psuedomonas aeruginosa is rarely pathogenic in?
Healthy individuals
What size is the genome?
5.5-7 Mb
What is the genome size of E.coli?
4.6Mb
Psuedomonas aeruginosa can grow where?
The environment and inside our bodies
What gives Pseudomonas aeruginosa the capacity to be so versatile?
- Has a large genome encoding multiple genes. Its genome is 5.5-7Mb which is much larger than that of E.coli (4.6Mb). It allows it to turn on different genes in different environments as required.
- It has a high metabolic diversity
- 8% of the genome comprises regulatory genes which are responsible for encoding products that can regulate the expression of multiple genes
Is it motile?
Yes
What are the different types of motility?
Swarming
Twitching
Swimming
Which motility is used in liquid environments?
Swimming
Which motility is used in semi-solid environments?
Swarming
Which motility is used on solid surfaces?
Twitching
When does swarming occur?
When there is low nutrient availability- local starvation
In response to certain amino acids
Swimming requires what?
Flagella
Swarming requires what?
Flagella- often hyperflagellated phenotype
Rhamnolipids
Twitching is performed using?
Type IV pili
Why are rhamnolipids required for swarming motiltiy?
They are postulated to lower the surface tension of the surface through their surfactant properties, allowing the bacterial cell to swarm
What is the function of rhamnolipids in swarming motility?
To lower the surface tension of the surface through their surfactant properties, allowing the bacterial cell to swarm
What pattern does swarming motility achieve?
Dendritic-like patterns
Psuedomonas aeruginosa produces two soluble pigments?
Pyocyanin and pyoverdine
Pyocyanin is what colour?
Blue
Pyoverdine is what colour?
Green
What is pyocyanin?
It is a blue redox-active secondary metabolite
What does pyocyanin do?
It can divert the electron flow and increase intracellular levels of reactive oxygen species e.g. H2O2. Causes damage to eukaryotic cells
What is pyoverdine?
It is a siderophore
What is pyocyanin?
It is a redox-active secondary metabolite
What is the precursor to pyocyanin?
Chorismic acid
What encodes pyocyanin?
Two sets of almost identical genes
Chorismic acid is converted into?
phenazine-1-carboxylic acid
Phenazine-1-carboxylic acid can be converted to pyocyanin via?
PhzM and PhzS
Pyoverdine is a?
Siderophore
The main function of pyoverdine as a siderophore is to?
Chelate iron- Fe3+ ions
How is ferripyoverdine transported back into the bacteria?
Outer membrane receptor FpvA
What is FpvA?
It is an outer membrane receptor
FpvA binds to?
Ferripyoveridine complex
Pyoverdine-mediated iron uptake by the FpvA receptor in the outer membrane of Pseudomonas aeruginosa is dependent on the inner membrane protein?
TonB
What is TonB?
An inner membrane protein
When ferripyoveridine binds the FpvA receptor what happens?
There is a conformational change which is generated by the interaction of TonB and FpvA. The conformational change opens up the receptor and allows the ferripyoverdine complex to enter
