Microbiology

Question 1

Which colour are gram positive and negative organism stained?

Answer 1

Gram positive - purple

Gram negative - pink

Question 2

Why are gram positive organisms stained purple?

Answer 2

Gram negatives have a thick peptidoglycan layer in the cell wall, which retains the crystal violet in the stain

Question 3

What are the different shapes of bacteria?

Answer 3

Cocci
Bacilli
Spiral

Question 4

What are cocci in strips, and what are cocci in clusters?

Answer 4

Strips - streptococci

Clusters - staphylococci

Question 5

How do bacteria replicate?

Answer 5

Binary fission

Question 6

Which bacteria secrete endotoxin and exotoxin?

Answer 6

Endo - gram negative

Exo - gram positive

Question 7

What is an opportunistic pathogen?

Answer 7

One that usually causes problems in immunocompromised patients

Question 8

What is pathogenicity?

Answer 8

Ability of an organism to cause disease/infect host

Question 9

What is virulence?

Answer 9

Degree of pathogenicity/severity of disease in host

Question 10

Are staph and strep gram positive or negative?

Answer 10

Positive

Question 11

Are staph and strep aerobic or anaerobic?

Answer 11

Aerobic

Question 12

Which test is done for staph, and which for strep?

Answer 12

Staph - coagulase test

Strep - haemolysis

Question 13

What are examples of alpha haemolytic strep?

Answer 13

Strep pneumoniae

Strep viridans

Question 14

What are examples of beta haemolytic strep?

Answer 14

Group A strep

Group B strep

Question 15

What are examples of non-haemolytic (gamma) strep?

Answer 15

Enterococcus

Question 16

What are coagulase positive staph?

Answer 16

Just staph aureus

Question 17

What does staph aureus look like on haemolysis?

Answer 17

Golden cocci in clusters

Question 18

What are coagulase negative staph?

Answer 18

Staph epidermidis

Question 19

What does strep pneumoniae cause?

Answer 19

Pneumonia

Meningitis

Question 20

What does strep viridans cause?

Answer 20

Endocarditis

Question 21

What does group A strep cause?

Answer 21

Throat and skin infection

Question 22

What does staph aureus cause?

Answer 22

Wound or skin infection

Lots more

Question 23

What does staph epidermidis cause?

Answer 23

Skin commensal

IV line infection

Question 24

Describe clostridium sp

Answer 24

gram positive anaerobic bacilli

Question 25

What is alpha haemolysis?

Answer 25

Partial haemolysis - green

Question 26

What is beta haemolysis?

Answer 26

Complete haemolysis

Question 27

What is gamma haemolysis?

Answer 27

No haemolysis

Question 28

What are gram negative strict aerobic bacilli?

Answer 28

Legionella | Pseudomonas aeruginosa

Question 29

What are gram negative aerobic cocci (diplococci)?

Answer 29

Neisseria gonorrhoea | Neisseria meningitides

Question 30

What are gram negative aerobic bacilli?

Answer 30

Haemophilus influenzae

Question 31

What are gram negative aerobic coliform (large bacilli)?

Answer 31

E coli | Klebiella

Question 32

What are microaerophilic gram negative bacilli?

Answer 32

Campylobacter | Helicobacter (spiral)

Question 33

What is the first line treatment of coliforms?

Answer 33

Gentamicin

Question 34

What is the process of viral replication?

Answer 34

``` Attachment Entry Uncoating Nucleic acid and protein synthesis Assembly Release ```

Question 35

What do bactericidal and bacteriostatic mean?

Answer 35

Bactericidal - kill bacteria | Bacteriostatic - inhibit bacterial growth

Question 36

What are the sites that antibiotics can work on?

Answer 36

Cell wall Ribosome DNA

Question 37

Which antibiotics work on the cell wall?

Answer 37

Penicillins Cephalosporins (e.g. ceftriaxone) Glycopeptides (e.g. vancomycin) All bactericidal

Question 38

When is flucloxacillin used?

Answer 38

Skin and soft tissue infection, wound infection in adults

Question 39

How do penicillins and cephalosporins work on the cell wall?

Answer 39

Stop cross linking and cause autolysins to degrade cell wall

Question 40

Are penicillins safe in pregnancy?

Answer 40

Yes

Question 41

Which antibiotics act on ribosomes?

Answer 41

Macrolides (e.g. erythromycin) Tetracyclines (e.g. doxycycline) Aminoglycosides (e.g. gentamicin)

Question 42

Which organisms does gentamicin generally act against?

Answer 42

Gram negative

Question 43

Which antibiotics act on bacterial DNA?

Answer 43

Metronidazole Trimethoprim Fluroquinolones

Question 44

What are the 4Cs?

Answer 44

Cephalosporins Co-amoxiclav Ciprofloxacin Clindamycin