chapter 26 (2)

Question 1

Chemical antimicrobial agents for external use

Answer 1

1. Products used to control microorganisms in commercial/industrial applications. —chemicals in foods…
2. Products that prevent growth of human pathogens in inanimate environments and on external body surfaces. –sanitizers, disinfectants…

Question 2

Sterilants

Answer 2

Destroy all forms of microbial life, including endospores.
Used where impractical to use heat or radiation.
Use of cold sterilization employing a gaseous chemical…
Liquid sterilants used on delicate instrument cannot withstand high temperatures or gas.

Question 3

Sanitizers

Answer 3

Role: to reduce, but may not eliminate microbial numbers to a level considered to be safe.

Question 4

Antiseptics and Disinfectants

Answer 4

Chemicals that kill or inhibit growth of bacteria.
Most bactericidal.
Applied only to skin because internally can kill host cell.
Antiseptic: applied to skin.
Disinfectant: applied to inanimate objects and surfaces.
Best against actively dividing cells…

Question 5

Characteristics of antibiotics

Answer 5

1. Low molecular weight
2. Produced by bacteria or fungi
3. Kill or inhibit growth of bacteria
4. Can be ingested or injected into human with minimal side effects

Question 6

Ideal antibiotics

Answer 6

Selective toxicity.
Favorable pharmacokinetics: reach target site w/ effective concentration.
Little resistance development.

Question 7

Antimicrobial agents: classified

Answer 7

Antimicrobial drugs are classified on the basis of:

1. molecular structure
2. mechanism of action
3. spectrum of antimicrobial activity

Question 8

Synthetic antimicrobial drugs

Answer 8

Paul Ehrlich studied selective toxicity in early 1900’s.

• ability to inhibit or kill a pathogen without affecting host.
• Salvarson: one of the first antimicrobial drugs.

Question 9

Synthetic antimicrobial drugs: growth factor analogs

Answer 9

Structurally similar to growth factors but do not function in the cell.

Question 10

Synthetic antimicrobial drugs: Sulfa drugs & Isoniazid.

Answer 10

Sulfa drugs: discovered by Gerhard Domagk in the 1930’s.
-Inhibit growth of bacteria
Isoniazid: growth analog effective only against Mycobacterium.
-Interferes with synthesis of my colic acid

Question 11

Synthetic antimicrobial drugs: Nucleic acid base analogs and Quinolones.

Answer 11

Nucleic acid base analogs: have been formed by addition of bromine or fluorine.
Quinolones: antibacterial compounds that interfere with DNA gyrase.