7. Antibiotics (Mode of Action) Flashcards Preview

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Flashcards in 7. Antibiotics (Mode of Action) Deck (16)
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1

Functions of antibiotics (2)

Break down gram-positive and gram-negative cell walls
Reduce competition for nutrients and space

2

Microbial growth control (2)

Physical
Chemical

3

Types of physical microbial growth control (2)

Heat sterilisation
Radiation sterilisation

4

Types of chemical microbial growth control (3)

Antiseptics (biological) and disinfectants (inanimate)
Natural antimicrobials
Synthetic antimicrobials

5

Definition of antibiotics (3)

Chemical substance produced by one organism that is destructive to another
Naturally occurring antimicrobials
Metabolic products of bacteria and fungi

6

Types of antibiotics (2)

Bacteriostatic
Bactericidal (better)

7

Cellular targets of antibiotics (4)

Cell wall
Cell membrane
Nucleic acid
Protein synthesis

8

Ideal antimicrobial agent features (8)

Selective toxicity against microbial target
Minimal toxicity to host
Cidal activity (kills micro-organisms)
Long plasma half-life
Good tissue distribution
Low binding to plasma proteins
Oral and parenteral preparations
No adverse interactions with other drugs

9

Antimicrobial targets/function (5)

Inhibition of cell wall synthesis
Inhibition of protein synthesis
Inhibition of nucleic acid replication and transcription
Injury to plasma membrane
Inhibition of synthesis of essential metabolites

10

Antimicrobials that inhibit cell wall synthesis (4)

Penicillins
Cephalosporins
Bacitracin
Vancomycin

11

Antimicrobials that inhibit protein synthesis (4)

Chloramphenicol
Erythromycin
Tetracyclines
Streptomycin

12

Antimicrobials that inhibit nucleic acid replication and transcription (2)

Quinolones
Rifampin

13

Antimicrobials that injure plasma membrane

Polymyxin B

14

Antimicrobials that inhibit synthesis of essential metabolites (2)

Sulphanilamide
Trimethoprim

15

How does antibiotic resistance develop

From misuse of antibiotics selected for resistant mutants

16

Examples of antibiotic misuse (5)

Using outdated or weakened antibiotics
Using antibiotics for a cold and other inappropriate conditions (viruses)
Using antibiotics in animal feed
Failing to complete prescribed antibiotic regiment
Using someone else’s (leftover) prescription