Pseudomonas

Question 1

Characteristics - Pseudomonas

Answer 1

Opportunistic pathogen, mainly comes from P. aeruginosa. Most common gram negative bacterium in nosocomial infections, higher change of infection in burn patients.

Question 2

Diseases caused - Pseudomonas

Answer 2

Burn infections, corneal keratitis, cystic fibrosis (leads to infection)

Question 3

Adhesion Virulence factors - Pseudomonas

Answer 3

type 4 pili, flagella. Can also bind to mucin and epithelial cells through non-pilus adhesion. Biofilm formation by exopolysaccharide

Question 4

Invasion/Replication Virulence factors - Pseudomonas

Answer 4

LasA and LasB which destroys host physical barriers and aids in spread. Both degrade elastin, with LasB also degrading fibrin and collagen. LasA nicks elastin, denaturing it and leaving it vl;nerable to LasB. Alkaline protease degrades parts of the cell helping with spread, nutrients and destruction of immune complexes. Exotoxin A helps with invasion

Question 5

Evasion Virulence factors - Pseudomonas

Answer 5

Exotoxin A helps with Evasion by suppressing B and T lymphocytes. Alkaline protease helps destroy immune complexes by inactivating IgG, IgA and complement system as well as inhibiting neutrophil chemotaxis. Biofilm formation by exopolysaccharide

Question 6

Toxins - Pseudomonas

Answer 6

Exotoxin A through a T3SS, responsible for local and systemic disease as well as tissue damage, helps with invasion and evasion. It is a catalyst for ADP-ribosylation, leading to inactivation of protein synthesis and elongation factor which leads to cell death. ExoT,S,Y,U are T3SS effector proteins. T-S = ADP-ribosyltransferase, GTPase activators. Y = actin-activated adenylate cyclase. U = phospholipase and potent cytotoxin

Question 7

Pathogenesis Corneal Keratitis - Pseudomonas

Answer 7

binds to innermost portion of tear layer where there is mucus. CFTR on epithelial cells which allow for pseudomonas to replicate inside corneal epithelial cells

Question 8

Burn infections pathogenesis - Pseudomonas

Answer 8

burns decrease physical barrier efficiency. Bacteria either non-invasive or invasive. Non-invasive infects non-viable skin and will have mild symptoms. Invasive infects viable tissue beneath the non-viable skin and destroys it, eventually becoming serpticaemic and has an 80% mortality rate

Question 9

Cystic fibrosis pathogenesis.- Pseudomonas

Answer 9

heavily increased mucus in lungs from CF causes P Aeruginosa infections to have an ideal place to colonise

Question 10

How are pseudomonas detected?

Answer 10

culture of wound swab

Question 11

How are pseudomonas treated?

Answer 11

antibiotics short term, no long term solution