Control of bacterial growth

Question 1

What are ways we can control bacterial growth

Answer 1

• Physical
• Chemical
• Biological

Question 2

Sterilization

Answer 2

Kill everything and spores

Question 3

Decontamination

Answer 3

treat to make them safe to handle

Question 4

Disinfection

Answer 4

Control pathogens on inanimate objects

Question 5

Antisepsis

Answer 5

Control pathogens in living tissues

Question 6

Sanitization

Answer 6

Lower microbe load

Question 7

Sepsis

Answer 7

Bacterial contamination

Question 8

Sepsis

Answer 8

Bodies reaction to bacterial infection

Question 9

“cidal”

Answer 9

Kill microbes

Question 10

“static”

Answer 10

Don’t kill, but won’t grow

Question 11

Factors influencing effectiveness of agents

Answer 11

• Number of microbes
• Environment
• Time of exposure
• Microbial features

Question 12

Modes of actions of antibacterials

Answer 12

• Alteration of membrane permeability
• Damage to proteins
• Damage nucleic acids

Question 13

What are physical methods of killing bacteria

Answer 13

• Heat
• Radiation
• Filtration

Question 14

Thermal death point

Answer 14

Lowest temp where all microbes are killed in 10 min

Question 15

What type of heat is most effective

Answer 15

Moist heat

Question 16

Types of dry heat

Answer 16

• Flaming
• Incineration
• Hot air sterilization

Question 17

Types of moist heat

Answer 17

• Boiling at 100C (doesn’t kill spores)
• Steam under pressure (autoclave) kills spores
• Pasteurization

Question 18

What is autoclaving

Answer 18

121C at 15 PSI for 15min or higher

Question 19

What is pasteurization

Answer 19

Use for liquids sensitive to heat but kills pathogens and prolongs shelf life. Can be HTST or ultra high temp

Question 20

Types of radiation

Answer 20

• Ionizing

- Nonionizing

Question 21

Ionizing radiation

Answer 21

X rays and gamma rays. Generate electrons, OH, and H to disrupt nucleic acids and proteins

Question 22

Nonionizing radiation

Answer 22

UV rays. Thymine dimers

Question 23

Filtration

Answer 23

Sterilize heat sensitive liquids. Filters exclude bacteria. HEPA filters

Question 24

Type of chemicals used to combat microbes

Answer 24

• Cidal

- Static

Question 25

Phenols

Answer 25

Active in presence of organic compounds and stable for a long time. Disrupts cytoplasmic membrane

Question 26

Phenol coefficient

Answer 26

Every other chemical is compared to the effectiveness of phenol. If it is greater than 1 it is more effective if less it is less effective

Question 27

Triclosan

Answer 27

Chlorinated diphenyl. Can become resistant to it as well as antibiotic resistant from it

Question 28

Chlorhexidine

Answer 28

Synthetic cationic antiseptic effective against bacteria but not spores. Used as presurg antiseptic, wound flush, and teat dip

Question 29

Halogen

Answer 29

Iodine and chlorine product

Question 30

Types of iodine

Answer 30

- Tincture (in alcohol) | - Iodophore (in organic molecule; betadaine)

Question 31

What type of alcohol is more effective

Answer 31

Isopropanol

Question 32

Heavy metal antimicrobial

Answer 32

- Silver nitrate - Mercury chloride - Copper sulfate - Zinc chloride

Question 33

Soaps

Answer 33

Not antiseptic, mechanically remove bacteria

Question 34

Quarternary ammonium compounds

Answer 34

Derivative of ammonia. good for Gram +

Question 35

Hydrogen peroxide

Answer 35

Useful for deep wounds to kill anaerobes not on superficial wounds

Question 36

Benzoyl peroxide

Answer 36

Treat wounds for anaerobes

Question 37

Peracetic acid

Answer 37

Kills spores in food

Question 38

Aldehydes

Answer 38

Formaldehydes etc. Inactivates bacteria

Question 39

Ethylene oxide

Answer 39

Gaseous sterilizers. Effective against all microbes over time. Denatures protein and sterilizes medical equipment