M1 +M2

Question 1

why is the cell wall important?

Answer 1

• structural barrier

- cell wall includes peptidoglycan

Question 2

what is a target of penicillin?

Answer 2

• FtsI

Question 3

is fimbrae/pilus gram- or gram + ?

Answer 3

gram -

Question 4

under which conditions can pyruvice acid be converted to lactic acid or ethanol?

Answer 4

anaerobic conditions

Question 5

for prokaryotic growth what is the source for carbon?

Answer 5

protein and sugars

Question 6

what factors are important in prokaryotic growth?

Answer 6

• food
• temperature
• hydrogen ion conc
• osmotic protection
• oxygen

Question 7

what are the stages in the bacterial growth?

Answer 7

• lag phase
• exponential phase
• stationary phase
• decline phase

Question 8

what is the definition of a virus?

Answer 8

• very small, obligate intracellular parasite

Question 9

what is the development of the oral flora in babies?

Answer 9

• microbiologically sterile until birth

Question 10

what are the two rules regarding standard infection control?

Answer 10

1. all patients maybe a carrier and therefore pose a significant risk
2. routine procedures must be sufficiently effective to protect against all possible infections and are routinely applied

Question 11

what is the golden rule of standard infection control?

Answer 11

the same cross infection control procedures must be used for all patients

Question 12

what are the structural differences between pro and euk?

Answer 12

pro

• no membrane
• circular chromosme
• peptidoglycan wall

euk

• membrane bound
• linear chromosome
• cell wall or envelope

Question 13

Give three benefits of culturing bacteria?

Answer 13

1. determines viability (aerobic vs anaerobic)
2. component special
3. provides pure material

Question 14

give advantages of transport media (general media)?

Answer 14

• includes charcoal which prevents desiccation and absorbs toxic agents
• rich in nutrients

Question 15

give an advantage of enrichment media?

Answer 15

• addition of blood/serum/extracts will support growth of fastidious organisms

Question 16

what is the advantage of using blood agar?

Answer 16

supports growth and allows haemolytic profiles to be determined

Question 17

which media allows the presence of specific substances permits the growth of one organism over another?

Answer 17

• selective media

Question 18

what does differential media allow you to determine?

Answer 18

incorporation of chemicals produces viable changes in colonies that facilitate identification

Question 19

classification of cocci

Answer 19

single coccus
pair of cocci
cluster of cocci (staphyloccci)
chains of cocci (streptococci)

Question 20

classification of rods (bacilli)

Answer 20

• single rod
• chains of rod
• curved rod (vibrio)
• spiral

Question 21

how can bacteria be biochemically characterised?

Answer 21

metabolic profiling

• Ability to produce acid (urease)
• identification - inoculate single colony
• then compare

Question 22

how do serological tests determine bacteria?

Answer 22

• Ab specific to microbe
• detect presence of specific IgM Ab to virus/microbe
• rapid detection

Question 23

what is the effect of agglutination?

Answer 23

antibody clumps with antigen to deactivate/destroy it

Question 24

why are virulence factors important?

Answer 24

allows us to find out severity of disease

Question 25

what does MALDI-TOF stand for?

Answer 25

Matrix
assisted
laser
desorption
time
of
flight

Question 26

what does MALDI-tof do?

Answer 26

• generates a series of ions
• mass analyzer - separates ions by mass to charge ratio
• detection device: detects spectrum of proteins