Anitmicrobial Chemotherapy From Chapter 20 In The Textbook

Front 1

Is only active against a limited variety of bacteria

Back 1

Narrow Spectrum

Front 2

1. Can inhibit the growth of a wide variety of Gram + and Gram – bacterial species
2. Often used for empirical or “blind” treatment of infections when the causative agents are unknown (but likely to be bacterial).

Back 2

Broad Spectrum

Front 3

Inhibits the growth of an organism

Back 3

Bacteriostatic

Front 4

Kills an organism

Back 4

Bacteriocidal

Front 5

Combination of antibiotics that has enhanced antibacterial activity (sum better than individual agents)

Back 5

Synergism

Front 6

Combination of antibiotics in which the activity of one or more agent interferes with the activity of others
(sum worse than individual agents)

Back 6

Antagonism

Front 7

List four characteristics of Anitmicrobial Agents

Back 7

1. Can be directly toxic
2. Can interact with other drugs to increase their toxicity
3. Can alter microbial flora
4. Can cause allergic reactions

Front 8

True/False:
Antibiotics can work independently from the immune system.

Back 8

False.
Antibiotics must work with the immune system. Antibacterial agents are not capable of completely eliminating an infection in a host with an extremely compromised immune systems
Antibiotics can not reach all sites in the body
Antibiotics only kill or inhibit sensitive organisms

Front 9

List the mechanisms by which bacteria exchange DNA

Back 9

1. Transformation
2. Conjugation
3. Transduction

Front 10

List the types of mobile elements

Back 10

1. transposons
2. plasmids
3. Phage
4. Conjugaive transposons
5. Pathogenicity Islands
6. Integrating Conjugative elements (ICEs) and other mobilizable elements

Front 11

use that maximizes therapeutic impact while minimizing toxicity and the development of resistance.

Back 11

Appropriate antimicrobial drug use

Front 12

emerges when drugs are prescribed inappropriately
1. Infections caused by viruses
2. Infections caused by bacteria not susceptible to the antibiotic
3. Antibiotics used at the wrong dose

Back 12

antibiotic resistance

Front 13

True/False

Appropriate antimicrobial drug use can simply be interpreted as simply reduced use.

Back 13

False

Appropriate antimicrobial drug use should not be interpreted simply as reduced use because these drugs offer valuable benefits when used appropriately.

Front 14

What are the types of antibacterial agents?

Back 14

1. Inhibition of Cell Wall Synthesis
2. Disruption of Membranes
3. Inhibition of Nucleic Acid Synthesis
4. Inhibition of Protein Synthesis
5. Antimetabolites

Front 15

Which phase is..
1. At the membrane
2. activated units are attached and assembled on the undecaprecol phosphate membrane pivot at the membrane.

Back 15

Phase 2

Front 16

Which Phase...
1. In cytoplasm
2. soluble substrates are activated and assembly and transport inside the cells

Back 16

Phase 1

Front 17

Which phase..
1. Outside the cell
2. The peptidoglycan units are attached to and cross-linked into the pepetidoglycan polysaccharide outside the cells

Back 17

Phase 3

Front 18

Drugs that inhibit polymerization and attachment of new peptidoglycan to cell wall

Back 18

Penicillins
Cephalosporins
Carbapenems and monbactams

Front 19

Drugs that inhibit biosynthetic enzymes

Back 19

Fosfomycin and Cycloserine

Front 20

Drugs that combine with carrier molecules

Back 20

Bacitracin

Front 21

Drugs that combine with cell wall substrates

Back 21

Vancomycin

Front 22

1. Inhibits the last step of cell wall synthesis, involving polymerization of peptidoglycan subunits
2. contain a four-membered ring
3. Penicillin-Binding Proteins (PBPs)

Back 22

b-lactam antibiotics

Front 23

b-lactam antibiotics where the b-lactam ring is fused with a dihydrothiazine ring.

have a wider antibacterial spectrum, resistance to many b-lactamases and have longer half-lifes improved pharmacokinetic properties over penicillins

Back 23

Cephalosporins

Front 24

related to Cephalosporins but are more resistant to b-lactamases

have a wider antibacterial spectrum, resistance to many b-lactamases and have longer half-lifes improved pharmacokinetic properties over penicillins

Back 24

Cephamycins

Front 25

a b-lactam antibiotic
Broad spectrum
Resistance has been reported in oxacillin-resistant staphylococci and Pseudomonas

Back 25

Carbapenems

Front 26

a b-lactam antibiotic
narrow spectrum
Effective only against aerobic Gram negative bacteria

Back 26

Monobactams

Front 27

Three general mechanisms for resistance to b-lactam antibiotics

Back 27

1. Prevention of the interaction between the PBP and the antibiotic
2. Modification of the interaction between the PBP and the antibiotic
3. Hydrolysis of the antibiotic by b-lactamases

Front 28

b-lactam Antibiotics Summary

Back 28

Mechanism of action
-inhibit polymerization and attachment of peptidoglycan to cell wall

Uses (spectrum)
-Range from narrow to broad depending on the particular compound

Mechanisms of resistance
-Exclusion from the target PBP
-Modification of the PBP
-b-lactamases

Front 29

Inhibition of biosynthetic enzymes

Back 29

Fosfomycin and Cycloserine

Front 30

1. Inhibits the enzyme UDP-GIcNAc-3-enol-pyruvyltransferase
2. Involved in the first phase of cell wall synthesis

Back 30

Fosfomycin

Front 31

1. an inhibitor of both alanine racemase and D-alanyl-D-alanine synthetase preventing the cross-linkage of peptidoglycan that occurs in the first phase of cell wall synthesis
2. fairly toxic and is generally only used as a secondary treatment for tuberculosis

Back 31

Cycloserine

Front 32

Drugs that combine with carrier molecules

Back 32

Bacitracin

Front 33

1. a peptide antibiotic that specifically interacts with the pyrophosphate derivate of the undecaprenyl alcohol, preventing further transfer of the muramylpentapeptide from the precursor nucleotide to the nascent peptidoglycan
2. This occurs in Phase II of Cell Wall Synthesis

Back 33

Bacitracin

Front 34

Drug that combine with cell wall substrates

Back 34

Vancomycin

Front 35

1. a glycopeptide.
2. binds to the pentapeptide terminus and inhibits both transglycosylation and transpeptidation reactions during peptidoglycan assembly
3. This occurs during phase II of cell wall synthesis

Back 35

Vancomycin

Front 36

1. not effective against Gram-negative bacteria because of its large size it can not penetrate the Gram-negative outer membrane
2. used to treat Gram-positive infections caused by organisms that are resistant to b-lactams

Back 36

Vancomycin

Front 37

Resistance:
1. Mediated by changes in the pentapeptide terminus
2. can be encoded on mobile genetic elements and can be trasferred from one species to another

Back 37

Vancomycin resistance

Front 38

bactericidal against actively replicating Mycobacteria

Back 38

Isoniazid

Front 39

inhibits synthesis of mycolic acid

Back 39

Isoniazid

Front 40

Resistance:
results both from decreased uptake of the drug into the cells and by alteration of the enzymes involved in mycolic acid synthesis

Back 40

Isoniazid

Front 41

Disruption of Membranes

Back 41

Polymyxins

polymyxin B and colistin (polymyxin E)

Front 42

1. High molecular-weight octapeptides
2. inhibit Gram-negative bacteria
3. Interact with the membrane and cause increased cell permeability
4. Only used topically - bind to various ligands in body tissues and are potent toxins for the kidney and nervous system

Back 42

Polymyxin

Front 43

Inhibition of DNA replicaiton

Back 43

The quinolones

Front 44

1. One of the most widely used class of antibiotics
2. Synthetic agents that inhibit gyrase (bacterial topoII) or topoisomerase IV thereby interfering with DNA replication, recombination and repair
3. In Gram negative bacteria gyrase is usually the primary target
4. In Gram positive bacteria topoIV is usually the primary target
5. Bactericidal

Back 44

The quinolones

Front 45

used to treat urinary tract infections caused by Gram negative bacteria but resistance to the drug developed rapidly

Back 45

Nalidixic acid

Front 46

DNA damaging agents

Back 46

the Nitroimidazoles

Front 47

1.Only inhibits anaerobic bacteria and protozoa
2.reduced by an electron transport protein in anaerobic bacteria. The reduced drug causes strand breaks in the DNA
3.Bactericidal

Back 47

Nitroimidazole

Front 48

Inhibition of Transcription

Back 48

Rifamycins

Front 49

1.bind to bacterial RNA polymerase and inhibit initiation of RNA synthesis
2.Bacteriocidal
3. active against many Gram positive bacteria
4. Hydrophobic, therefore the outermembrane of Gram negatives inhibit uptake
5. resisance develops rapidly

Back 49

Rifamycins