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Flashcards in Basic Microbiology Deck (36):
0

How are streptococci further classified?

Patterns of haemolysis α,β,γ

1

What is meant by α haemolysis and how how it appear?

Partial haemolysis
Agar goes green

2

What is meant by β haemolysis and how how it appear?

Complete haemolysis
Agar goes clear

3

What is meant by γ haemolysis and how how it appear?

No haemolysis
Agar stays red

4

What is the lancefield classification?

A way of further classifying β haemolytic strep depending on their carbohydrate composition in their cell wall antigens

5

Give an example of an α haemolytic strep

Strep pneumoniae
Strep viridans

6

Given an example of a group A haemolytic strep

Strep pyogenes

7

Give an example of a group B haemolytic strep

Strep agalactiae

8

Give an example of a γ haemolytic strep

Enterococcus faecalis
Enterococcus faecium

9

What type of organism is strep pneumoniae?

α haemolytic strep
Gram positive cocci

10

What type of organism is strep viridans?

α haemolytic strep
Gram positive cocci

11

What type of organism is strep pyogenes?

Group A haemolytic strep
Gram positive cocci

12

What type of organism is strep agalactiae?

Group B haemolytic strep
Gram positive cocci

13

What type of organism is enterococcus faecalis?

γ haemolytic strep
Gram positive cocci

14

Give some examples of gram negative aerobes

Neisseria meningitides, gonorrhoea
E. coli
H influenza
Legionella
Campylobacter
Shigella
Salmonella

15

Give an example of a gram negative cocci

Neisseria meningitides
Neisseria gonorrhoea

16

Give an example of a gram negative bacilli

E coli
Klebsiella
Enterobacter
Pseudomonas
Salmonella

17

Give an example of a gram negative coccobacilli

H influenzae
Chlamydia
Bordetella pertussis

18

Give an example of a gram positive cocci

Staphylococci
Streptococci

19

How are staphylococci further classified?

Coagulase positive
Coagulase negative

20

Give an example of a Coagulase positive staphylococcus

S aureus

21

Give an example of a coagulase negative staphylococcus

S epidermidis
S saprophyticus

22

What is the function of coagulase in bacteria?

Protein enzyme
Catalysed conversion of fibrinogen to fibrin upon contact with blood, which coats the bacteria and protects it from phagocytosis

23

Which test can be used to differentiate between staphylococci and streptococci?

Catalase test

24

How does the catalase test work?

If the bacteria possesses catalase, oxygen bubbles will form when they are added to hydrogen peroxide

25

What colour do gram positive and gram negative organisms appear on gram staining and why?

Positive - dark blue or purple
Negative - red or pink

Gram positive organisms have a thicker peptidoglycan cell wall which retains the stain

26

Give an example of gram positive bacilli

Clostridium difficile
Listeria

27

What type of organism is H influenzae?

Gam negative coccobacilli

28

What type of organism is chlamydia trachomatis?

Gram negative coccobacilli

29

What type of organism is Neisseria?

Gram negative cocci

30

What type of organism is E. coli?

Gram negative bacilli

31

What type of organism is salmonella?

Gram negative bacilli

32

What type of organism is pseudomonas?

Gram negative bacilli

33

What type of organism is Staph aureus?

Gram positive cocci
Coagulase positive

34

What type of organism is C diff?

Gram positive bacilli

35

What type of organism is staph epidermidis?

Gram positive cocci
Coagulase negative