Gram Positive Cocci

Question 1

What bacteria is catalase positive and coagulase positive

Answer 1

Staph Aureus

Question 2

What bacteria are catalase positive and coagulase negative

Answer 2

Staph Spp.
Staph Epidermidis
Staph Saprophyticus

Question 3

What does the catalase test differentiate between

Answer 3

Staph and Strep genus
Staph = catalase +ve
Strep = coagulase -ve
Apply hydrogen peroxidase 3% to pure colony = bubbling = +ve

Question 4

What does coagulase test differentiate between

Answer 4

S.aureus and coagulase negative staphococcus (CONS)
Apply rabbit plasma to a sample of pure colony. Observe for fibrin clot lumps.

Question 5

What bacteria is catalase negative, alpha haemolytic on blood agar and optician resistant

Answer 5

S. Mitis

Question 6

What bacteria is catalase negative, alpha haemolytic on blood agar and optician sensitive

Answer 6

S. pneumoniae

Question 7

What bacteria is catalase negative, beta haemolytic on blood agar and Lancefield group A

Answer 7

S. pyogenes

Question 8

What bacteria is catalase negative, beta haemolytic on blood agar and Lancefield group B

Answer 8

S. agalactiae

Question 9

What bacteria is catalase negative, beta haemolytic on blood agar and Lancefield group C

Answer 9

S. dysgalactiae

Question 10

What bacteria is catalase negative, beta haemolytic on blood agar and Lancefield group D

Answer 10

S. bovis or enterococcus faecalis

Question 11

What is the haemolysis test

Answer 11

Alpha - partial haemolysis causing by product = hydrogen peroxide oxidising haemoglobin - the agar appears green
Beta = complete haemolysis because of lysis of red blood cell by haemolysis such as streptolysin O by s.pyogenes
Gamma - haemolysis implies no haemolysis.

Question 12

Difference between community acquired pneumonia and hospital acquired

Answer 12

CAP = symptoms first occur less than 24 hours in hospital

Question 13

Most common cause of CAP

Answer 13

s.pneumoniae

Question 14

Typical causes of CAP

Answer 14

H.influenzae
Moraxella catarrhalis

Question 15

Atypical causes of CAP

Answer 15

Mycoplasma pneumoniae
Chlamydophilia pneumonie
Legionella pneumoniae

Question 16

Diagnosis of CAP

Answer 16

CXR with new consolidation sputum or blood culture
CURB-65

Question 17

Treatment of CAP

Answer 17

First line = amoxicillin
Co-amoxiclav if unwell
Otherwise guided by micro

Question 18

Which people most likely to get HAP

Answer 18

Usually people on ventilators, stroke, long stays, infectious contact

Question 19

Most common cause of HAP

Answer 19

E.coli
Klebsiella pneumonae

Question 20

Other causes of HAP

Answer 20

Enterobacter spp.
Pseudomonas aeruginosa
Acinetobacter baumannii
Stenotophomonas maltophilla
MRSA
Streptococci

Question 21

Diagnosis of HAP

Answer 21

CXR with new consolidation, sputum or blood culture

Question 22

Treatment of HAP

Answer 22

Guided by micro
Often IV co-amoxiclav and gentamycin