Bacteria - Structure and Classification Flashcards Preview

Infection Medicine > Bacteria - Structure and Classification > Flashcards

Flashcards in Bacteria - Structure and Classification Deck (51):
1

 

 

What is gram staining?

 

 

Method of staining bacterial cells where bacteria are stained with crystal violet dye

2

 

 

What is gram positive?

 

 

Class of bacteria which retains crystal violet - due to thick peptidoglycan layer

PURPLE COLOUR

A image thumb
3

 

 

What is gram negative?

 

 

Class of bacteria which do not retain crystal violet dye - Thin peptidoglycan layer sandwiched between inner and outer cell membrane

A image thumb
4

 

 

What is the outer membrane in gram negative organisms called?

 

 

Lipopolysaccharide (LPS) - which is anchored to peptidoglycan by lipoproteins

5

 

 

What are the main classes of bacteria by shape?

 

  • Cocci - spherical
    • Diplococcus - 2 cocci
    • Streptococcus - chain
    • Staphylococcus - cluster
  • Bacilli - rod shaped
  • Spirilli - spiral shaped

A image thumb
6

 

 

What is the capsule of a bacteria?

 

 

Polysaccharide layer that lies outside the cell envelope of some prokaryotes. It is considered a virulence factor. It can protect cells from phagocytosis, and can protect bacteria from desiccation.

A image thumb
7

 

 

What are flagellae?

 

 

Whip like structures that consist of helical filaments which help the bacteria rapidly propel themselves through different media.

8

 

 

What are fimbriae?

 

An appendage composed of curlin proteins that can be found on most gram positive bacteria and some gram negative bacteria. It is thinner and shorter than a flagellum. They are used to adhere to each other, animal cells, and inanimate objects.

A image thumb
9

 

 

What is a Plasmid?

 

 

Mobile, independent, self-replicating circular units of dsDNA. They carry genes that may benefit the organisms survival, and can frequently be transmitted between organisms by horizontal gene transfer.

A image thumb
10

 

 

What class of bacteria is S. Aureus?

 

 

Gram Positive Coagulase positive (has coagulase enzyme) Cocci

11

 

 

Can you name Gram positive coagulase negative Staphylococci?

 

  • S. hominis
  • S. epidermidis
  • S. Haemolyticus

12

 

 

What class of bacteria is S. Pneumoniae?

 

 

Gram positive, alpha-haemolytic cocci

13

 

 

What does alpha haemolysis mean?

 

 

Partial haemolysis

14

 

 

What class of bacteria is S. viridans?

 

 

Gram positive, alpha haemolytic cocci

15

 

 

What indicates partial haemolysis on blood agar plate?

 

Agar turns green - hydrogen peroxide produced by bacteria due to oxidation of haemoglobin to methoglobin

A image thumb
16

 

 

What is beta-haemolysis?

 

 

Complete haemolysis - turns blood agar clear

A image thumb
17

 

 

What does lancefield serotyping describe?

 

 

Specific carbohydrates present in the bacterial cell wall. Groups A, B and D are most clinically significant

18

 

 

What class of bacteria is S. Pyogenes?

 

 

Gram negative, beta haemolytic group A strep

19

 

 

What class of bacteria is S. agalactiae?

 

 

Gram positive, beta-haemolytic Group B strep

20

 

 

What can S. pneumoniae (Group A strep) cause?

 

 

  • Sore throats
  • Cellulitis
  • Necrotising fasciitis

 

21

 

 

What class of bacteria is E. Faecalis?

 

 

Gram positive, non-haemolytic group D strep

22

 

 

What class of bacteria are enterococci?

 

 

Gram positive, non-haemolytic streptococci

23

 

 

What class of bacteria is L. monocytogenes?

 

 

Gram positive, aerobic bacilli

24

 

 

What class of bacteria is diptheria?

 

 

Gram positive, aerobic bacilli

25

 

 

What class of bacteria is C. difficile?

 

 

Gram positive, anaerobic bacilli

26

 

 

What class of bacteria is C. Perfringens?

 

 

Gram positive, anaerobic bacilli

27

 

 

What class of bacteria is C. Tetani?

 

 

Gram positive, anaerobic bacilli

28

 

 

What class of bacteria is N. meningitidis (meningococcus)?

 

 

Gram negative diplococcus

29

 

 

What class of bacteria is N. gonorrhoae?

 

 

Gram negative diplococcus

30

 

 

What class of bacteria is M. catarrhalis?

 

 

Gram negative cocci

31

 

 

What class of bacteria is E. Coli?

 

 

Gram negative lactose fermenting bacilli

32

 

 

What class of bacteria is S. enterica?

 

 

Gram negative, non-lactose fermenting bacilli

33

 

 

What class of bacteria is S. typhi?

 

 

Gram negative bacilli

34

 

 

What class of bacteria is Shigella?

 

 

Gram-negative bacilli

35

 

 

What class of bacteria is K. pneumoniae?

 

 

Gram-negative, lactose fermenting bacilli

36

 

 

What class of bacteria is Proteus spp.?

 

 

Gram negative bacilli

37

 

 

What are coliforms?

 

 

Gram-negative bacilli which can ferment lactose with the production of acid and gas when incubated at 35–37°C. Normally found in the gut

38

 

 

What class of bacteria are Campylobacter spp.?

 

 

Gram negative, S-shaped bacteria

39

 

 

What class of bacteria is H. Pylori?

 

 

Gram Negative, curved rods

40

 

 

What class of bacteria is H. Influenzae?

 

 

Gram Negative, cocco-bacilli

41

 

 

What class of bacteria is Pseudomonas spp.?

 

 

Gram negative, aerobic bacilli

42

 

 

What class of bacteria is Bacteriodes spp.?

 

 

Gram-negative, anaerobic bacilli

43

 

 

What is the staining used to identify mycobacterium?

 

 

Ziehl-Neelsen Stain

44

 

 

What is does a positive Ziehl-Neelsen Staining mean?

 

 

Resistant to decolourisation by acid or alcohol following carbol fuschin staining

45

 

 

What is a Spirochaete?

 

 

Long, spiral shaped bacteria, which is most easily seen by immunoflourescence

A image thumb
46

 

 

What class of bacteria is T. Pallidum?

 

 

Spirochaete

47

 

 

What class of bacteria is borellia burgdoferri?

 

 

Spriochaete

48

 

 

What class of bacteria is Leptospira?

 

 

Spirochaete

49

 

 

What class of bacteria is Chlamydia trachomatis?

 

 

Gram negative ovoid bacteria

50

 

 

What class of bacteria is Legionella pneumophila?

 

 

Gram-negative

51