Antibiotics

Question 1

What is the most common mechanism of antibiotic activity

Answer 1

Effects on cell wall integrity
- Interferes with cell wall synthesis

Question 2

How do beta lactams work

Answer 2

Target serine proteases and penicillin binding proteins
- Inhibits assembly and degrade cell wall

Question 3

Four different beta lactams

Answer 3

• Penicillin
• Cephalosporin
• Monobactams
• Carbapenems

Question 4

What is commonly associated with Clostridium difficile infections?

Answer 4

3rd generation/broad spectrum cephalosporins

Question 5

Penicillin effective against mostly…

Answer 5

Gram +

Question 6

Cephalosporins mostly effective against…

Answer 6

G- with each generation, but also some G+

Question 7

Monobactams mostly effective against

Answer 7

Aerobic G-

Question 8

Carbapenems mostly effective against

Answer 8

G+, G-, anaerobes

Question 9

Glycopeptides/vancomycin

Answer 9

Targets cell wall
- Targets G+

Question 10

Lipopeptides/daptomycin

Answer 10

Cell membrane inhibitor
Disruption of ionic concentration gradiet of the cell membrane
- Targets G+

Question 11

Polypeptides

2 types

Answer 11

Cell membrane target
Bacitracin: topical, G+
Polymyxins/colistin: topical or IV, G-

Question 12

Antimycobacterial

2 types

Answer 12

Inhibit mycolic acid synthesis in cell wall
Isoniazid and ethambutol

Question 13

Prokaryotic ribosomes are made up of what?

Answer 13

30s and 50s subunits on the mRNA that lead to translation of genetic message

Question 14

What are the 3 antibiotics that target the 30s ribosomal subunit

Answer 14

• Aminoglycosides
• Tetracycline
• Glycylcycline

Question 15

The six antibiotics that target the 50s ribosomal subunit

Answer 15

• Macrolides
• Lincosamide
• Chloramphenicol
• Oxazolidinone
• Streptogramins
• Ketolides

Question 16

Aminoglycosides

Answer 16

30s
- Almost always used with cell wall synthesis inhibitors
- Anaerobes are usually resistant
- GNR, some GP, mycobacteria

Question 17

Tetracyclines

Answer 17

30s
- G+, G-, mycoplasma, chlamydiae, rickettsiae
- Not give to <8 yo children, preg women
- Food decreases absorption

Question 18

Glycylcyclines

Answer 18

30s
- Similar to tetracyclines
- More against G-, anaerobes, rapid growing mycobacteria

Question 19

Macrolides

Answer 19

50s
- Aerobic and anaerobic G+ cocci

Question 20

Lincosamides

Answer 20

50s
- G+ cocci, anaerobes
- C. difficile diarrhea

Question 21

Chloramphenicol

Answer 21

50s
- G+, G-, anaerobes, chlamydiae, mycoplasma, rickettsiae
- Aplastic anemia risk, backfire against human protein synthesis

Question 22

Oxazolidinones

Answer 22

50s
- Aerobic G+, mycobacteria, anaerobes

Question 23

Streptogramin

Answer 23

50s
- G+, anaerobes

Question 24

Ketolides

Answer 24

50s
- Similar to erythromycins from macrolides
- - G+ cocci

Question 25

What was the first effective systemic antimicrobial used in the US in the 1930s

Answer 25

Essential metabolite antimicrobials

Question 26

Sulfonamides

Answer 26

Essential metabolite inhibitor

Question 27

Trimethoprim

Answer 27

Essential metabolite inhibitor

Question 28

Inhibitors of DNA **replication**

Answer 28

Quinolones/fluoroquinolones

Question 29

Interfere with DNA **transcription**

Answer 29

Rifampin

Question 30

Causes **breaks in DNA**

Answer 30

Metronidazole

Question 31

Drug of choice for bacterial vaginosis

Answer 31

Metronidazole

Question 32

Group at the heart of multi drug antibiotic resistance

Answer 32

ESKAPE - ENFA - STAU - KLPN - ACBA - PSAE - Enterobacter species

Question 33

Multi drug resistance

Answer 33

Resistance to at least 1 in 3 or more antimicrobial categories

Question 34

Extensively drug resistant

Answer 34

Resistance in at least one in ALL but 1-2 antimicrobial categories

Question 35

Pan drug resistant

Answer 35

Resistant to everything

Question 36

Preventing resistance

Answer 36

Vaccination Infection control Protect food supply Antibiotic responsibility Screening, treatment, education

Question 37

Intrinsic mechanisms of antimicrobial resistance

Answer 37

Impermeability barriers Biofilms Drug efflux Enzyme inactivation or degradation

Question 38

Horizontal gene transfer: transformation

Answer 38

Parts of DNA taken up by bacteria from outside environment

Question 39

Horizontal gene transfer: conjugation

Answer 39

Cell to cell contact between two bacteria and transfer plasmids

Question 40

Horizontal gene transfer: transduction

Answer 40

Bacteria specific viruses transfer DNA between 2 closely related bacteria | Bacteriophag

Question 41

Intrinsic antimicrobial resistance: impermeability barriers

Answer 41

- LPS - Can reduce the number of porins or change sructure to reduce affinity for antibiotics

Question 42

Intrinsic antimicrobial resistance: biofilms

Answer 42

Motile bacteria attached to substrate - Decreased penetration of antibiotic - Slowed bacterial growth

Question 43

Intrinsic antimicrobial resistance: drug efflux

Answer 43

Pumps that transport the antibiotic back out of the cell

Question 44

Intrinsic antimicrobial resistance: enzyme inactivation/degradation

Answer 44

Self explanatory

Question 45

Fourextrinsic antimicrobial resistance mechanisms

Answer 45

Efflux Target site modification Antibiotic alteration Enzymatic inactivtion

Question 46

How to combat beta lactam antibiotics

Answer 46

- Making enzyme beta lactamase - alter antibiotic target site - alter porin channels

Question 47

How to combat glycopeptides

Answer 47

- Alter antibiotic target site

Question 48

How to combat aminoglycosides

Answer 48

- Alter antibiotic target site - Modify antibiotic - Alter porin channels

Question 49

How to combat quinolones

Answer 49

- Alter antibiotic binding site - efflux

Question 50

What is MIC?

Answer 50

Minimum inhibitory concentration that visibly inhibits growth of the test organism