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Flashcards in Microbiology Deck (45)
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1

Gram+ organisms stain...

Purple
Stain well due to thick peptidoglycan layer

2

Gram- organisms stain...

Pink
Thinner peptidoglycan layer doesn't retain stain well

3

Endotoxin is produced by...

Gram- organisms
Part of the cell wall

4

Exotoxin is produced by...

Gram+ organisms
Exported from the cell

5

Gram+ cocci in chains are?

Streptococci

6

Gram+ cocci in clusters are?

Staphylococci

7

The test to classify different Streptococci spp.?

Haemolysis
Alpha (partial) - Strep. pneumoniae + viridans
Beta (complete) - Group A (pyogenes) and B Strep.
Gamma (none) - Enterococcus sp.

8

Examples of: Alpha-haemolytic Streptococci?

Strep. pneumoniae + "viridans" group

9

Examples of: Beta-haemolytic Streptococci?

Group A Strep. (Strep. pyogenes), Group B Strep.

10

Examples of: Non-haemolytic Streptococci?

Enterococcus sp.

11

The test to distinguish Staphylococcus aureus from other Staph. spp.?

Coagulase test
+ve = Staph. aureus
-ve = other Staph. spp. (common skin commensals)

12

Treatment of choice for Staph. aureus infection?

Flucloxacillin

13

Examples of gram- cocci in pairs (diplococci)

Neisseria meningitidis and Neisseria gonorrhoeae

14

Some examples of Gram- bacilli

Bordetella
H. influenzae
Coliforms
Pseudomonas
Campylobacter

15

Examples of coliforms that are gut commensals

E. coli
Klebsiella sp.
Proteus sp.

16

Examples of coliforms that are gut pathogens

Salmonella sp.
Shigella sp.
E. coli 0157

17

The name of the toxin produced by E. coli 0157 is...

Verotoxin (VTEC)

18

Treatment of choice for coliform infections?

Gentamicin

19

Examples of strict aerobes (2)

Pseudomonas sp. (Gram- bacilli)
Legionella sp. (Gram- bacilli)

20

Examples of strict anaerobes (2)

Clostridium spp. (Gram+ bacilli)
Bacteroides spp. (Gram- bacilli)

21

Treatment of choice for anaerobic infections?

Metronidazole

22

Genetic variation in bacteria is dangerous because...

Resistance to antibiotics may develop.

23

Gene transfer: Transformation

DNA from dead bacteria is taken up by living bacteria and incorporated into plasmids/bacterial chromosome.

24

Gene transfer: Conjugation

Sex pilus forms between bacteria to allow transfer of plasmid DNA.

25

Gene transfer: Transduction

Viruses can transfer bacterial DNA between cells they infect.

26

The 5 methods of spread of infection are...

Inhalation, Ingestion, Inoculation, mother to Infant, Intercourse

27

Viruses contain RNA or DNA, never both. True/False?

True
Size of their capsid (protein coat) limits space

28

Bactericidal antibiotics inhibit cell growth. True/False?

False
Kill bacteria directly - bacteriostatic inhibits cell growth

29

Vancomycin is part of which family of antibiotics?

Glycopeptides

30

Penicillins, cephalosporins and glycopeptides act on the bacterial ___ ___

Cell wall