Bacteraemia & Septicaemia

Question 1

Define Bacteraemia

Answer 1

Bacteraemia is the presence of bacteria within the blood. It can be asymptomatic if the immune system clears it however it can cause problems if unable to be cleared. Usually benign bacteria in the blood

Question 2

Define Septicaemia

Answer 2

Bacteria within the blood that are active and multiplying. They bring systemic signs of infection such as increased HR, fever, raised WBC level due to PAMPs.

Question 3

Define Sepsis

Answer 3

the clinical manifestation of septicaemia

Question 4

Define Septic shock

Answer 4

Severe cases of sepsis that lead to a massive drop in blood pressure - usually irreversible in its effects

For example: Gram neagative bacteria in the blood stream can exhibit LPS that are recognised by the immune system. Monocytes release chemokines/cytokines in response (Il6, Il1, TNF) that can activate chemotaxis, adhesion, degranulation etc. Monoctyes also release tissue factor that activates coagulation. This can lead to:
- loss of fluid in tissues
- fall in blood pressure
= Septic Shock

Question 5

What are some common bacteria associated with bacteraemia and septicaemia

Answer 5

G +ve: S. aureua, S. pyogenes, S. epidermidis, S. pneumonia, Enterococcus sp.
G -ve: Psuedomonas sp.

Question 6

What is MALDI-TOF?

Answer 6

Technique based on mass spectrometry that will allow the identification of a previously identified organism,

Question 7

Usually, we take blood for testing before administering antibiotic treatments however this is not the case in Meningitis, why?

Answer 7

During Meningitis, Antimicrobial therapies must be given as soon as possible and so it is an exception to the rule “Take blood before giving antimicrobial treatment”