Antibiotics

Question 1

Bacitracin

Answer 1

Gram +
Bactericidal
Cell wall - peptidoglycan polymerization

Question 2

Fosfomycin

Answer 2

Gram + & -
Bactericidal
Cell wall - NAG formation

Question 3

Cycloserine

Answer 3

Cell wall - prevents D-Ala-D-Ala bond

Question 4

Beta lactams

Answer 4

Broad spectrum
Bactericidal
Cell wall - inhibit penicillin bind proteins/crosslinking

R membered ring - similar to D-Ala

Question 5

Penicllins

Answer 5

Beta-lactam
Bactericidal
Cell wall

Question 6

Cephalosporins

Answer 6

Beta-lactam
Bactericidal
Cell wall

Question 7

Carbapenems

Answer 7

Beta-lactam
Bactericidal
Cell wall

Question 8

Monobactams

Answer 8

Beta-lactam
Bactericidal
Cell wall

Question 9

Glycopeptides

Answer 9

Gram +
Bactericidal
Cell wall - prevents crosslinking, acts on PBP

Ex. vancomycin

Question 10

Lipoglycopeptides

Answer 10

Gram +
Bactericidal
Cell wall & membrane - prevents crosslinking, acts

Question 11

Acid-fast bacilli

Answer 11

Ethambutol - arabinogalactan
Isoniazid and ethionamide - mycolic acid synthesis

Question 12

Cell wall targeting

Answer 12

Affect bacteria when they are growing dividing

Question 13

Cell membrane targeting

Answer 13

Intercalation into lipid membrane by forming pores or carpets

Question 14

Sulfonamides

Answer 14

Gram + & -
Bacteriostatic
Folate metabolism - inhibit PABA (earlier)

Question 15

Trimethoprim

Answer 15

Gram + & -
Bacteriostatic
Folate metabolism - inhibit dihydrofolate reductase

Question 16

Bactrim

Answer 16

Comines sulfonamide and trimethoprim

Bactericidal

Question 17

Quinolones

Answer 17

Gram + & -
DNA replication - inhibit topoisomerase

2 six member rings

Question 18

Nitroimidazoles

Answer 18

Bactericidal
DNA replication - cytotoxic product, promote strand breakage

Question 19

Nitrofurans

Answer 19

Same as nitroimidazoles (Bactericidal
DNA replication - cytotoxic product, promote strand breakage) but only aerobic bacteria

Question 20

Rifamycin

Answer 20

Gram + & -
Bactericidal
RNA replication - inhibit RNA polymerase

Question 21

Macrocyclics

Answer 21

Only C. difficile
RNA replication - blocks RNA poly binding

Question 22

Aminoglycosides

Answer 22

Bactericidal
Protein synthesis - incorrect insertion of amino acids

Question 23

Tetracyclines

Answer 23

Bacteriostatic
Protein synthesis - amino acids can’t be inserted

Question 24

Glyclyclines

Answer 24

Bacteriostatic
Protein synthesis - amino acids can’t be inserted

Question 25

Macrolides

Answer 25

Bind reversibly Protein synthesis - prevent amino acid chain from existing

Question 26

Ketolides

Answer 26

Bind reversibly Protein synthesis - prevent amino acid chain from existing Like macrolide but 2 bindings sites instead of one

Question 27

Lincosamides

Answer 27

Bind reversibly Protein synthesis - prevent amino acid elongation

Question 28

Chloramphenicol

Answer 28

Bind reversibly Protein synthesis - prevent amino acid elongation Slightly different binding site to lincosamide

Question 29

Streptogramins

Answer 29

Protein synthesis - prevent peptide bond formation and elongation

Question 30

Macrolides, Lincosamides, Streptogramins

Answer 30

All bind to same area but slightly different actions

Question 31

Oxazolidinones

Answer 31

Gram + Protein synthesis - inhibit initiation

Question 32

Pleuromutilins

Answer 32

Gram + Bacteriostatic Protein synthesis - prevent initiation and elongation

Question 33

Fusidic acid

Answer 33

Gram + & - Bacteriostatic Protein synthesis - prevent energy for motion of ribosome

Question 34

Breakpoint

Answer 34

MIC when bacteria is deemed susceptible or non-susceptible to antibiotic

Question 35

MIC testing

Answer 35

Borth dilution E-test (ruler in plate) Kirby-Bauer (patches of antibiotic)

Question 36

Post-antibiotic effect

Answer 36

How long is antibiotic effective when concentration is less than MIC

Question 37

AUC/MIC dosing

Answer 37

Time and concentration dependent Interval and dose Antibiotic is reversibly inhibiting so have to keep up activity Glycopeptides Consider toxicity

Question 38

T dosing

Answer 38

Time dependent More frequent interval, irreversible but over time, new formed so have to keep up with killing Penicillin

Question 39

Cmax/MIC dosing

Answer 39

Depends on PAE Large dosing, one large dose is enough because it is irreversible - causes PAE because effects last even after Aminoglycoside

Question 40

General resistance

Answer 40

Outer membrane proteins - block entry of antibiotic Efflux pump - low level resistance, can be unregulated

Question 41

Beta-lactam resistance

Answer 41

PBP don't bind well (MRSA) Decreased permeability Modifying enzymes Beta-lactamases on the rise (esp group 2)

Question 42

Beta-lactamases

Answer 42

Produced by bacteria to break down beta-lactam antibiotics ESBL MBL KPC CRE

Question 43

KPC & CRE

Answer 43

On the rise, source of concern Esp CRE because it is to common bacteria

Question 44

NDM-1

Answer 44

Easily transferred amongst people, many resistance genes

Question 45

Quinolone resistance

Answer 45

Mutations in DNA gyrase/topoismerase Decreased permeability Active efflux pumps Protection of DNA gyrase/topoisomerase

Question 46

Aminoglycoside resistance

Answer 46

Methylation of rRNA Decreased permeability Active efflux pumps Direct inactivation

Question 47

MLSB

Answer 47

Reisstance to one - resistance to all Methylation of rRNA Active efflux pumps

Question 48

Linezolid resistance

Answer 48

Methylation of rRNA