1. Pseudomonas Infection

Question 1

What are the stages of the chain of infection ?

Answer 1

Infectious agent.
Reservoir.
Portal of exit.
Mode of transmission.
Portal of entry.
Susceptible host.

Question 2

What type of bacteria is pseudomonas aeruginosa ?

Answer 2

Gram negative bacilli.

Question 3

What is the key virulence factor of pseudomonas aeruginosa ? What is its function ?

Answer 3

Extracellular polysaccharide capsule.
Defence mechanism - inhibit and slows penetration of antibacterials.

Question 4

What are the potential endogenous sources of pseudomonas infection ?

Answer 4

Oral flora (transient commensal).
Hands.

Question 5

What are the potential exogenous sources of pseudomonas infection ?

Answer 5

Water - dental unit water supply.
Suction system.
Aerosols.
Hands.
Inadequate decontamination.

Question 6

Mode of transmission - what are ways of reducing risk of pseudomonas infection which a dentist can take ?

Answer 6

Use of type B steriliser - wrapping prior to sterilisation.
Segregate clean from dirty.

Question 7

Portal of exit - give examples of portal of exit for pseudomonas infection ?

Answer 7

Aerosols produced from dental unit waterlines.
Splashing from sinks.

Question 8

Known as opportunistic pathogen - what patients are considered susceptible patients to pseudomonas infection ?

Answer 8

Cystic fibrosis.
Post-op eye infections.
Septicaemia in neutropenic.
Burn/graft infection.
Hospital acquired pneumonia.
Catheter associated urine infections.