Antimicrobials

Question 1

What are the 3 targets of antibiotics/microbials?

Answer 1

Peptidoglycan layer of cell wall (1)

Inhibition of bacterial protein synthesis (2)

DNA gyrase and other prokaryote-specific enzymes (3)

Question 2

What 2 groups of antimicrobials inhibit cell wall synthesis?

Answer 2

1. B-lactam antibiotics

2. Glycopeptides

Question 3

Name examples of drugs that inhibit cell wall synthesis from the b-lactam group

Answer 3

Penicillin i.e. amoxicillin

Cephalosporin i.e. cefuroxime

Carbapenems i.e. Meropenem

Question 4

what class of drug is teicoplanin?

Answer 4

glycopeptide

inhibits cell wall synthesis

Question 5

what class of drug is vancomycin?

Answer 5

glycopeptide

inhibits cell wall synthesis

Question 6

Streptococci are what type of bacteria?

Answer 6

gram positive

Question 7

which is the most active beta lactam drug subclass?

Answer 7

penicillin

Question 8

which has the thin peptidoglycan wall?

Answer 8

gram NEGATIVE bacteria

remember: negative = less peptidoglycan

Question 9

which drug class inactivates / mainly targets transpeptidases?

Answer 9

B lactams i.e. Penicillin etc

Question 10

Can B-lactams be used against mycoplasma?

Answer 10

No as no peptidoglycan

Question 11

which penicillin is not broken down by S aureus

Answer 11

flucoxacillin

Question 12

what is a beta-lactamase?

Answer 12

made by S aureus

breaks down most pencillins

Question 13

Can B-lactams be used against chlamydia?

Answer 13

No as no peptidoglycan

Question 14

clavulanic acid is what class of drug?

Answer 14

beta-lactamase inhibitors

protect penicillins from breakdown by beta-lactamase

Question 15

Tazobactam is what class of drug?

Answer 15

beta-lactamase inhibitors

protect penicillins from breakdown by beta-lactamase

Question 16

which drugs work for gram negatives?

Answer 16

Cephalosporins (3rd gens in particular)

so other b-lactams are gram positive cover

Question 17

A patient present with meningitis which drug class to use and why?

Answer 17

Cephalosporins for gram neg cover

particularly - CEFTRIAXONE

Question 18

What is an Extended Spectrum Beta-Lactamase (ESBL)?

Answer 18

breakdown cephalosporins as well as penicillins

Question 19

What drugs used against ESBL?

Answer 19

cephalosporins i.e. morepenem

Question 20

which drug class are:
Imipenem
Ertapenem

Answer 20

cephalosporins

Question 21

which drugs are bactericidal?

Answer 21

b lactams

glycopepetides

Question 22

glycopeptides cover gram __ bacteria?

Answer 22

positive

remember - peptide = large = can’t cross

Question 23

oral vancomycin is what class of drug and treatment example?

Answer 23

Glycopeptide

C difficile

Question 24

what prevents glycosidic bonds and peptide cross links from forming?

Answer 24

glycopeptides

Question 25

how are glycopeptides different from b lactams

Answer 25

bind to the binding site of the enzymes rather than enzymes themselves

Question 26

TAMCO group of drugs work via which mechanism of action?

Answer 26

inhibit protein synthesis

Question 27

TAMCO stands for?

Answer 27

``` • Tetracyclines • Aminoglycosides (e.g. gentamicin) • The MSL Group ○ Macrolides (e.g. erythromycin) etc • Chloramphenicol • Oxazolidinones ```

Question 28

amikacin is what type of drug?

Answer 28

aminoglycoside

Question 29

tobramycin is what type of drug?

Answer 29

aminoglycoside

Question 30

which drug class is ototoxic and nephrotoxic

Answer 30

aminoglycosides glycopeptides - nephro

Question 31

aminoglycosides won't work against?

Answer 31

anaerobes i.e. Actinomyces, Bacteroides, Clostridium | abscesses

Question 32

patient with pseudomonas aeroginosa which drug to use?

Answer 32

Gentamicin or tobramycin fluorquinolones i.e. ciproflocaxin

Question 33

which drugs prevent elongation of peptide chain?

Answer 33

aminoglycosides

Question 34

which drug NOT to give to pregnant women and kids?.

Answer 34

tetracycline

Question 35

Which drug is effective against intracellular pathogens (e.g. Chlamydiae, Rickettsiae and Mycoplasmas)

Answer 35

tetracycline

Question 36

tetracycline works via what MOA?

Answer 36

bacteriostatic

Question 37

patient gets light sensitive rash AND teeth discolouration what drug have they taken?

Answer 37

tetracycline

Question 38

which drug binds to the ribosomal 30S subunit?

Answer 38

tetracycline

Question 39

which drug binds to the ribosomal 50S subunit?

Answer 39

Macrolides

Question 40

which drug binds to the peptidyl transferase OF the ribosomal 50S subunit?

Answer 40

chloramphenicol stops peptide bond formation

Question 41

tetracycline macrolide chloramphenicol have which MOA in common?

Answer 41

bacteriostatic

Question 42

which drug may cause thrombocytopaenia and optic neuritis

Answer 42

Oxazolidinones (E.g. Linezolid)

Question 43

which 2 drug classes act as Inhibitors of DNA Synthesis

Answer 43

• (flour)Quinolones ○ Ciprofloxacin, Levofloxacin, Moxifloxacin • Nitroimidazoles ○ Metronidazole, Tinidazole

Question 44

which drug class Act on the alpha-subunit of DNA gyrase ?

Answer 44

flouroQuinolones

Question 45

flouroQuinolones act on gram __ bacteria?

Answer 45

negative

Question 46

which drugs are active against anaerobic bacteria and protozoa?

Answer 46

Nitroimidazoles i.e Metronidazole, Tinidazole

Question 47

which drug concentrates in the bladder?

Answer 47

nitrofurantoin

Question 48

Which drug should NEVER be used as a single agent because resistance develops rapidly due to chromosomal mutation?

Answer 48

Rifampicin

Question 49

Which drugs acts as Cell Membrane Toxins?

Answer 49

Daptomycin and Colistin

Question 50

Sulphonamides and Diaminopyrimidines work via which MOA?

Answer 50

Inhibitors of Folate Metabolism examples are; sulphamethoxazole + trimethoprim

Question 51

Beta-lactamases are a major mechanism of resistance to beta-lactams adopted by which organisms?

Answer 51

s. aureus e.COLI Klebsiella's

Question 52

which organisms causes resistance through coding PBP2a through the meta gene?

Answer 52

MRSA

Question 53

which organisms causes resistance through mutations in the PBP gene?

Answer 53

Streptococcus pneumoniae

Question 54

which drug is Rarely used because risk of aplastic anaemia and grey baby syndrome ?

Answer 54

chloramphenicol

Question 55

which drug turns contacts orange?

Answer 55

rifampicin

Question 56

name 2 abx for use in c diff rx?

Answer 56

1st - PO Metronidazole (can give IV if severe) ``` PO Vancomycin (no IV) - if above fails ```

Question 57

non drug rx for c dpi??

Answer 57

faecal transfer colon resection IVIG - because the young can make antibodies against c diff.

Question 58

possible abx rx for ESBL e.coli?

Answer 58

mirapenem

Question 59

possible abx rx for MRSA

Answer 59

Vancomycin

Question 60

rx for PCP?

Answer 60

Co-trimoxazole + high dose steroid

Question 61

in PCP patients classically presnet how?

Answer 61

SOB Desaturate on walking (O2 sats drop) Dry cough

Question 62

which antibiotics are most implicated as causes of c diff? essential knowldege for ID rotations!

Answer 62

Cephalosporins (especially second and third generation) - Ceftriaxone!! Fluoroquinolones - levofloxacin Ampicillin/amoxicillin Clindamycin