Mircobiology Basics

Question 1

what do aerobic bacteria require

Answer 1

oxygen

Question 2

difference between gram +ve and gram -ve bacteria

Answer 2

gram +ve have thick peptidoglycan wall that stains with crystal violet
gram -ve don’t have thick peptidoglycan wall and don’t stain with crystal violet

Question 3

what shape are:

• bacilli
• cocci

Answer 3

bacilli = rods
cocci = circular

Question 4

where does protein synthesis occur in bacteria

Answer 4

ribosomes

Question 5

what colour do gram +ve bacteria stain

Answer 5

purple

crystal violet stain binds to cell wall in gram +ve bacteria

Question 6

what colour do gram -ve bacteria stain

Answer 6

pink

counterstain is added that binds to the cell membrane in gram -ve bacteria that don’t have cell wall

Question 7

examples of gram positive cocci

Answer 7

staphylococcus
streptococcus
enterococcus

Question 8

examples of gram positive bacilli

Answer 8

mycobacteria
listeria
bacillus

Question 9

examples of gram positive anaerobes

Answer 9

clostridium

lactobacillus

Question 10

what are ESBLs

Answer 10

extended spectrum beta lactamase bacteria

• bacteria that produce beta lactamase enzymes
• resistant to broad range of antibiotics

Question 11

examples of ESBLs

Answer 11

E.coli

Klebsiella

Question 12

treatment of ESBLs

Answer 12

meropenem
imipenem
(carbapenems)

Question 13

example of a strict aerobe (requires oxygen)

Answer 13

pseudomonas

Question 14

what are coliforms

Answer 14

organisms that inhabit large bowel

Question 15

what are pseudomonas and coliforms sensitive to

Answer 15

Gentamicin

Question 16

Gentamicin belongs to which class of antibiotic

Answer 16

Aminoglycosides

Question 17

how does gentamicin act

Answer 17

inhibits protein synthesis

Question 18

what are anaerobic bacteria sensitive to

Answer 18

metronidazole

Question 19

where does metronidazole act

Answer 19

cell DNA

Question 20

where do penicillins + cephalosporins act

Answer 20

cell wall

Question 21

what antibiotics inhibit protein synthesis

Answer 21

gentamicin
tetracylines e.g doxycycline
macrolides e.g. clarithromycin

Question 22

what bacteria is coagulate positive

Answer 22

staph aureus

Question 23

what is alpha haemolysis?

what organisms are responsible?

Answer 23

partial haemolysisis

• strep pneumoniae
• strep viridans

Question 24

what is beta haemolysis?

what organisms are responsible?

Answer 24

complete haemolysis

- Group A + B strep

Question 25

treatment of staph aureus

Answer 25

flucloxacillin

Question 26

treatment of MRSA

Answer 26

vancomycin