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Introduction to Clinical Sciences > Microbiology > Flashcards

Flashcards in Microbiology Deck (22)
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1
Q

What colour do Gram positive bacteria stain?

A

Purple

2
Q

What colour do Gram negative bacteria stain?

A

Pink

3
Q

What does the catalase test show?

A

It differentiates between Staph (catalase positive) and Strep (catalase negative)

4
Q

What is gamma haemolysis?

A

No haemolysis

5
Q

What is alpha haemolysis?

A

Partial haemolysis?

6
Q

What is beta haemolysis?

A

Complete haemolysis

7
Q

What test differentiates between beta haemolytic strep?

A

Lancefield grouping

8
Q

What bacteria is group A strep?

A

Streptococcus pyogenes

9
Q

What bacteria is optochin resistant?

A

Strep. viridans

10
Q

What bacteria is optochin sensitive?

A

Strep. pneumoniae

11
Q

What is the coagulase test for?

A

To differentiate between Staph

12
Q

What colour colonies are Staph. aureus?

A

Golden on blood agar

13
Q

What bacteria test coagulase positive?

A

S. aureus

14
Q

What bacteria test coagulase negative?

A

S. epidermidis

15
Q

What test narrows down which Gram negative bacteria is growing?

A

Lactose fermenting - MacConkey agar or CLED agar or XLD

16
Q

Name some important lactose fermenters

A

E. coli

17
Q

Name some important non-lactose fermenters

A

Salmonella, Yersinia, Shigella

18
Q

Under the microscope after Gram staining, it is reported that the organism from the sample you sent is Gram negative. What organism are you worried about?

A

Neisseria meningitidis

19
Q

What is infective endocarditis?

A

An infection of the endocardial lined structures e.g. heart valves

20
Q

What organisms commonly cause infective endocarditis?

A

Strep. viridans, S. aureus, S. epidermidis

21
Q

What are the clinical features of infective endocarditis?

A
Fever
Splinter haemorrhages
Janeway lesions
Osler's nodes
Roth spots
New murmur
Malaise
Symptoms of septic emboli e.g. stroke, PE, pneumonia
22
Q

What agar is used to grow H. influenzae?

A

Chocolate agar.

Factors X and V are released which H. influenzae to grow