Chemical Growth Control

Question 1

Examples of QAC

Answer 1

Detergents, lysol, cepacol, soaps

Question 2

• Kirby-Bauer Antimicrobial Assay
• Observe for the zone of inhibition

Answer 2

Disc Diffusion Technique

Question 3

• Kill organisms (not endospores)
• Use on inanimate objects

Answer 3

Disinfectants

Question 4

• Nontoxic agents that can kill or inhibit growth of organisms
• Use on living tissues

Answer 4

Antiseptics and germicides

Question 5

Inhibits growth

Answer 5

Statics

Question 6

MOA of QAC

Answer 6

• Probably disrupts the membrane
• Interacts with phospholipids

Question 7

What is alcohol?

Answer 7

Antiseptic (most effective at 70%)

Question 8

Examples of Alkylating Agents

Answer 8

• Formaldehyde
• Gluteraldehyde (spore killers)
• Ethylene oxide
• OPA (ortho-pthalaldehyde)

Question 9

Uses of Alkylating Agents

Answer 9

• Surface disinfectant, sterilant for temp-sensitive materials (plastic, lenses)
• High0level disinfectant for medical insturments

Question 10

• Antiseptic
• Mode of Action (MOA): disrupts cytoplasmic membrane, denatures DNA, inactivates enzymes

Answer 10

Phenol and Phenolics

Question 11

Kills microorganisms

Answer 11

Cidals

Question 12

Halogens are

Answer 12

Sterilant, disinfectant, sanitizer

Question 13

Destroy all forms of microorganisms, including endospores

Answer 13

Sterilant

Question 14

Alkylating Agents

Answer 14

Disinfectant, sterilant

Question 15

Uses of halogens

Answer 15

Topical antiseptic, disinfectant of lab surfaces

Question 16

Reduce microbial numbers

Answer 16

Sanitizers

Question 17

MOA of Oxidizing Agents

Answer 17

• Disrupt disulfide bonds in proteins
• Membrane and protein stability

Question 18

Examples of Alkylating Agents

Answer 18

• Formaldehyde
• Gluteraldehyde (spore killers)
• Ethylene oxide
• OPA (ortho-pthalaldehyde)

Question 19

Uses of QAC

Answer 19

• Medical, food, and dairy equipment
• Soaps, lotions, topical disinfectant

Question 20

Examples of halogens

Answer 20

• Iodine, chlorine, mercuric dichloride
• Betadine
• Chlorox

Question 21

• Inhibitors of protein synthesis
• Binding to ribosomes
• Viable and total cells are the same

Answer 21

Bacteriostatic

Question 22

Oxidizing Agents

Answer 22

Antiseptic, disinfectant, sterilant

Question 23

MOA of Halogens

Answer 23

• Iodine binds to tyrosine residues of proteins, inhibits protein production
• Iodine oxidizes sulfhydryl groups and disrupts protein structure
• Water + Cl = hypochlorous acid (oxidizing agent)

Question 24

MOA of Alkylating Agents

Answer 24

Disrupts proteins and structure of nucleic acid

Question 25

- Tube dilution technique - smallest amount of agent needed to inhibit microbial growth - Observe for the clear tube

Answer 25

Minimum Inhibitory Concentration (MIC)

Question 26

Examples of Alkylating Agents

Answer 26

- Formaldehyde - Gluteraldehyde (spore killers) - Ethylene oxide - OPA (ortho-pthalaldehyde)

Question 27

- Kills by cell lysis; release of cytoplasmic contents - Decreased viable and total cell number

Answer 27

Bacteriolytic

Question 28

Examples or Oxidizing Agents

Answer 28

- Hydrogen peroxide - Potassium permanganate

Question 29

Uses of phenol/phenolics

Answer 29

Soaps, lotions, cosmetics, body deodorants, PineSol

Question 30

- Binds to cellular target, kills - Dead cells are not destroyed - Viable cells are killed, but turbidity is constant

Answer 30

Bacteriocidal

Question 31

Factors that affect MIC

Answer 31

- Bacterial species - Inoculum size - Culture medium - Incubation conditions

Question 32

Quaternary Ammonium Compounds

Answer 32

- Disinfectant - Antiseptic - Sanitizer

Question 33

Examples of phenol/pehnolics

Answer 33

Lysol, hexachlorophene, trichlosan

Question 34

Uses of alcohol

Answer 34

Topical antiseptic

Question 35

MOA of Alcohol

Answer 35

- Denatures proteins (water must be present) - Disrupts cellular membrane - Lipid solvent