Introduction to Microbes

Question 1

Where does angular chelitis present?

Answer 1

at the angles of the mouth

Question 2

What bacteria causes angular chelitis?

Answer 2

staphylococcus aureus

Question 3

What is minimum inhibitory concentration?

Answer 3

lowest concentration of an anti-microbial that will inhibit visible growth of microorganism

Question 4

What does a leukocidin do?

Answer 4

Kills white blood cells

Question 5

What does capnophilic mean?

Answer 5

carbon dioxide

Question 6

What does facultative mean?

Answer 6

with and without oxygen

Question 7

what does aerobic mean?

Answer 7

oxygen

Question 8

What does anaerobic mean?

Answer 8

without oxygen

Question 9

What does microaerophilic mean?

Answer 9

small amounts of oxygen

Question 10

What are the stages of bacterial growth?

Answer 10

Lag, log, stationary, death

Question 11

What happens in the lag phase?

Answer 11

bacteria get used to surroundings

Question 12

What happens in log phase?

Answer 12

replicate exponentially

Question 13

What happens in stationary phase?

Answer 13

growth rate = death rate

Question 14

What happens in death phase?

Answer 14

no growth mediums so cell death

Question 15

What is the D-value?

Answer 15

The time taken to kill 90% of bacteria

Question 16

What are the different shapes of bacteria?

Answer 16

Rod shaped = BACILLI round shaped = COCCI spiral shape

Question 17

What are the steps of gram staining?

Answer 17

primary stain, fixative (iodine), decoloriser (alcohol/acetone), counterstain

Question 18

What is the colour of gram+ bacteria after staining?

Answer 18

purple

Question 19

What is the colour of gram- bacteria after staining?

Answer 19

pink/red

Question 20

Why do gram+ cells stain violet?

Answer 20

due to the presence of a thick layer of peptidoglycan

Question 21

Why do gram- cells stain pink?

Answer 21

thinner peptidoglycan wall

Question 22

what makes up the cell wall of gram- cells?

Answer 22

lipopolysaccharide

Question 23

what is a lipopolysaccharide?

Answer 23

an endotoxin

Question 24

Where do endotoxins come from?

Answer 24

produced by gram- bacteria

Question 25

what is an example of an endotoxin?

Answer 25

prevotella intermedia

Question 26

where do exotoxins come from?

Answer 26

produced by gram+ or gram- bacteria

Question 27

What is an example of an exotoxin?

Answer 27

staphylococcus aureus

Question 28

Name 3 gram+ bacteria

Answer 28

staphylococcus aureus, streptococcus mutans, clostridium difficile

Question 29

Name 2 gram- bacteria

Answer 29

neisseria meningitidis, prevotella intermedia

Question 30

What does staphylococcus aureus cause?

Answer 30

surgical site infections

Question 31

What does streptococcus mutans cause?

Answer 31

dental caries

Question 32

What does clostridium difficile cause?

Answer 32

antibiotic associated diarrhoea

Question 33

what does neisseria meningitidis cause?

Answer 33

meningitis

Question 34

what does prevotella intermedia cause?

Answer 34

periodontal disease

Question 35

what shapes are gram+ bacteria?

Answer 35

bacilli (rod) and cocci (sphere shaped)

Question 36

What shapes are gram- bacteria?

Answer 36

cocci (sphere shaped)