Streptococcus Pneumoniae

Question 1

What sort of diseases can it cause?

Answer 1

Bacterial pneumonia (most common cause)
Otitis Media (Ear ache)
Sepsis (esp. if asplenic)
Meningitis(affects children, young adults and the elderly)

Question 2

Gram positive/negative?

Answer 2

Positive

Question 3

Shape?

Answer 3

Cocci

Question 4

Normal site?

Answer 4

Nasopharnyx of many healthy individuals

Question 5

What two ways can it cause infection

Answer 5

Develop impaired resistance to the bacteria (eg alcoholism, malnutrition, depressed immune system, asplenic). causes illness through nasopharnyx (endogenously)

Exogenously- Droplets from the nose of carrier

Question 6

Name some virulence factors and what effect these have on the body

Answer 6

Capsule: antiphagocytic and antigenic
Pili: Attachment to epithelial cells of the upper resp tract
Autolysis: Responsible for the release of intracellular virulence factors (eg. Pneumolysin)
Pneumolysin: Attacks cell membranes–>lysis

Question 7

Investigations to test for this bacteria

Answer 7

Its alpha haemolytic- Wet, moist looking, green on blood agar
Gram stain- Purple, lancet shaped, diplococci

Question 8

Treatment?

Answer 8

Vancomysin or 3rd generation cephalosporins

Question 9

Prevention?

Answer 9

Vaccines