Acute Infection Flashcards
Which toxin is secreted by the T2SS?
Exotoxin A
T2SS secretes toxins where?
Into the extracellular space
T6SS is used for what?
To secrete effectors into bacterial cells where they can cause cell damage. Effectors that are able to cleave DNA, impact the cell integrity of the target bacterium by interfering with the cell wall/membrane.
T3SS is used for what?
To kill eukaryotic cells
To infect effectors directly into eukaryotic cells to harm them
What is the most toxic virulence factor of P.aeruginosa?
Exotoxin A
Exotoxin A is secreted by?
T2SS
Exotoxin A is toxic how?
Cleaves EF2- elongation factor 2 which is needed for translation
Prevents protein synthesis
T2SS secretes exotoxin A where?
Into the extracellular space
What are the three domains of exotoxin A?
Has a receptor binding domain
Has a translocation domain
Has a catalytic domain
Exotoxin A is what type of toxin?
It is a proenzyme
What is the main difference between the effectors of P.aeruginosa T3SS and those of the pathogenic E.coli T3SS?
The T3SS of P.aeruginosa only secretes types of 4 effectors which is different to pathogenic E.coli which is able to secrete a range
What are the 4 possible T3SS effectors?
STUY ExoS ExoT ExoU ExoY
A P.aeruginosa never has?
Both ExoS and ExoU
Which effectors are very similar and share the same chaperone?
ExoS and ExoT
What is the importance of chaperones?
To ensure the appropriate delivery of effectors into the eukaryotic cells.
What is the chaperone for ExoS and ExoT?
SpcS
ExoS and ExoT share the same molecular chaperone known as?
SpcS
ExoY has which chaperone?
No chaperone identified
ExoU has which chaperone?
SpcU
What are the two catalytic domains of ExoS and ExoT?
GTPase activating domain- GAP domain
ADPRT: Adenosine diphosphate ribosyltransferase domain
What are all the domains present in ExoS and ExoT?
CBD- chaperone binding domain
MTD- membrane translocation domain
GAP domain
ADPRT domain
Which catalytic domain in ExoS/ExoT is N-terminal?
GAP domain
Which catalytic domain in ExoS/ExoT is C-terminal?
ADPRT domain
Describe the structure of ExoS/ExoT?
S secretion signal CBD MLD GAP catalytic domain ADPRT catalytic domain
ExoU is only found in strains?
Lacking ExoS
Chaperone for ExoU?
SpcU
Catalytic domains of ExoU?
Phospholipase domain
What does the phospholipase domain do?
It can degrade phospholipids
Degrade the eukaryotic cell membrane- interfere with the integrity of the eukaryotic cell membrane and can result in cell death
In comparison to ExoS/ExoT what is different about ExoU?
It causes rapid cell death
Causes cell death much quicker
What is the most toxic T3SS effector?
ExoU
ExoY chaperone?
No chaperone has been identified
ExoY catalytic domain?
Adenylate cyclase
Adenylate cyclase causes?
Intracellular cAMP accumulation
This cAMP can lead to the expression of multiple genes regulated by cAMP. Can disrupt the actin cytoskeleton and increase endothelial permeability.
What is associated with acute infection?
Acute infection is associated with:
T3SS
Virulence factors e.g. T2SS: Exotoxin A, T3SS: Exo T,U,S,Y, virulence factors from QS: hydrogen cyanide etc…
Motility
