Microbiology

Question 1

What are the three ways an antibiotic can act on the cell?

Answer 1

Act on the bacterial cell wall
Affecting the bacterial ribosome
Acting on bacterial DNA directly

Question 2

Penicillins act to break the bacterial strand of DNA - True/False?

Answer 2

False - they act to inhibit cell wall synthesis

Question 3

What facilitates the action of penicillins?

Answer 3

b-lactam ring

Question 4

What are the benefits of using penicillin?

Answer 4

safe to use in healthy and pregnant patients

Question 5

What are the disadvantages of penicillins?

Answer 5

Hypersensitivity in some patients

Rapid excretion requires more frequent dosing

Question 6

What species is penicillin effective on?

Answer 6

Clostridium
Streptococcum
Bacteroides
Neisseria
S. Aureus

Question 7

Clostridium

Answer 7

Gram +

Question 8

Streptococcus

Answer 8

Gram +

Question 9

Bacteroides

Answer 9

Gram -

Question 10

Neisserin

Answer 10

Gram -

Question 11

Staphylococcus

Answer 11

Gram +

Question 12

What types of bacteria is Flucloxacillin effective against?

Answer 12

Gram +

Question 13

Flucloxacillin is narrow spectrum - True/False?

Answer 13

True

Question 14

What types of bacteria is flucloxacillin used against?

Answer 14

staphylococci

streptococci

Question 15

What sort of infection is flucloxacillin used for?

Answer 15

skin infection, wound infection, cellulitis

Question 16

For what type of infection is Flucloxacillin the drug of choice?

Answer 16

Staphylococcus aureus

Question 17

What are the benefits of amoxicillin?

Answer 17

safe and well tolerated

Question 18

What are the disadvantages of amoxicillin?

Answer 18

less effective in bacteria which have developed b-lactamase

Question 19

What species is amoxicillin effective against?

Answer 19

Clostridium
Streptococcus
Enterococcus
E.coli
Haemophilus influenzae
Neisseria
Bacteroides

Question 20

Enterococcus

Answer 20

Gram +

Question 21

E.Coli

Answer 21

Gram -

Question 22

Haemophilus Influenzae

Answer 22

Gram -

Question 23

Neisseria

Answer 23

gram -

Question 24

What is co-amoxiclav?

Answer 24

combined antibiotic, amoxicillin and clavulanic acid

Question 25

What is clavulanic acid?

Answer 25

b-lactamase inhibitor

Question 26

Which bacteria can co-amoxiclav treat that amoxicillin cannot?

Answer 26

staphylococcus | improves outcomes for other species

Question 27

Piperacillin/Tazobactam?

Answer 27

Combination of antibiotic and tazobactam b-lactamase inhibitor

Question 28

What does piperacillin/Tazobactam treat?

Answer 28

almost anything apart from MRSA and resistanct coliforms

Question 29

How do cephalosporins act?

Answer 29

inhibit cell wall synthesis by preventing cross linking of peptidoglycan

Question 30

What is the disadvantage of cephalosporins?

Answer 30

significantly affect normal gut flora

Question 31

Give a first gen cephalosporin

Answer 31

cefalexin -UTI

Question 32

2nd Gen cephalosporin

Answer 32

cefuroxime

Question 33

3rd Gen Cephalosporin

Answer 33

cefixime - Gonnorhoea | ceftriaxone - meningitis

Question 34

4th Gen Cephalosporin

Answer 34

Ceftazidime - pseudomonas

Question 35

Glycopeptides

Answer 35

Vancomycin | Teicoplanin

Question 36

How do glycopeptides work?

Answer 36

inhibit cell wall synthesis but by binding growing pentapeptide chains and preventing cross-linking

Question 37

What are the issues with glycopeptides?

Answer 37

Has to be given IV Can be toxic to renal failure patients Not absorbed from the gut

Question 38

What infection can vancomycin be used to treat?

Answer 38

C.diff

Question 39

What forms of antibiotics affect protein synthesis?

Answer 39

macrolides tetracyclines aminoglycosides

Question 40

How do antibiotics affecting proteins synthesis work?

Answer 40

attach to bacterial ribosomes - bacteriostatic not bacteriacidal

Question 41

What is the exception to the bacteriostatic rule in protein synthesis?

Answer 41

aminoglycosides where binding the ribosome is lethal

Question 42

Examples of macrolides

Answer 42

erythromycin clarithromycin azithromycin

Question 43

How are macrolides excreted?

Answer 43

liver --> biliary tract --> gut

Question 44

What are macrolides particularly useful for treating?

Answer 44

intracellular bacteria because they are lipophillic and can pass through cell membrane Legionella

Question 45

Which macrolide is safe in pregnancy?

Answer 45

erythromycin

Question 46

Where are macrolides useful?

Answer 46

where bacteria do not have a proper cell wall

Question 47

Which species do macrolides work well on?

Answer 47

``` clostridium streptococcus enterococcus staphylococus MRSA Neisseria Haemophilia influenzae Bacteroides ```

Question 48

Aminoglycoside

Answer 48

Gentamycin

Question 49

What do aminoglycosides mostly act on?

Answer 49

Gram -, aerobic organisms, coliforms, pseudomonas

Question 50

What are the disadvantages of aminoglycosides?

Answer 50

narrow therapeutic index damage to kidneys damage to VIII cranial nerve - deafness and balance issues

Question 51

Which species do aminoglycosides act on?

Answer 51

``` MRSA S.Aureus Pseudomonas aeruginosa E.coli Neisseria ```

Question 52

Tetracycline in Tayside

Answer 52

Doxycycline

Question 53

What is doxycycline useful for treating?

Answer 53

atypical pneumonia | chest/skin infections in patients who are penicillin allergic