Chapter 7 The Control Of Microbial Growth

Front 1

Sepsis

Back 1

Microbial contamination

Front 2

Asespsis

Back 2

Absence of significant contamination

Front 3

Aseptic surgery technique

Back 3

Prevent microbial contamination of wounds

Front 4

Sterilization

Back 4

Removal of all microbial life

Front 5

Commericial sterilzation

Back 5

Killing C botulinum endospores in canned food

Front 6

Disinfection

Back 6

Removal of pathogens

Front 7

Antisepsis

Back 7

Removal of pathogens from living tissue

Front 8

Degerming

Back 8

Removal of microbes from a limited area

Front 9

Sanitization

Back 9

Lower microbial counts on eating utensils

Front 10

Biocide/Germicide

Back 10

Kills microbes

Front 11

Bacteriostasis

Back 11

Inhibting, not klling, microbes (refrigerator)

Front 12

One log decrease

Back 12

90 percent of population killed

Front 13

Bacterial population death

Back 13

Constant logarithmic rate when treated

Front 14

Effectiveness of antimicrobial treatment

Back 14

Number of microbes

Environment (organic matter, temperature, biofilms)

Time of exposure

Microbial characteristics (capsules/spores)

Front 15

Action of Microbial Control agents

Back 15

Alternation of permeable membrane-Damage to plasma membrane

Damage to proteins-especially enzymes

Damage to nucleic acids - DNA or RNA

Front 16

Heat: Thermal Death Point

Back 16

Lowest temperature at which all cells in a culture are killed in 10 min. Lower temp may not damage vitamins or antibiotics or damage products

Front 17

Heat: Thermal Death Time

Back 17

Time to kill all cells in a culture

Front 18

Decimal reducton time

Back 18

Minutes to kill 90% of a population at a given temperature

Front 19

DRT or D Value

Back 19

Decimal Reduction time

Front 20

Moist Heat

Back 20

Denatures proteins (breaks hydrogen bonds between nucleotides) boiling

Front 21

Autoclave

Back 21

Steam under pressure

Front 22

Steam sterilization

Back 22

Steam must contact item's surface

Steam does pass through foil

Use paper to wrap objects

Use sterility indicators (tape or spore vials)

Front 23

Pasteurization

Back 23

Reduces pathogenic microbes which elimates spoilage.

Front 24

Equivalent pastuerization treatments

Back 24

63C for 30 min traditionally

High temperature, short time: 72C for 15 sec

Ultra high tempature: 140C for <1sec

Thermoduric organisms survive

Front 25

Dry heat

Back 25

Sterilizaiton kills by oxidation

Flaming, Incineration, Hot air sterilization

Hot air 170C @ 2 hours =

Autoclave 121C @ 15 min

Front 26

Filtration

Back 26

Removes microbes

Front 27

Low Temperature

Back 27

Inibits microbial growth

Doesn't work on Listeria

Slow deep freezing ruptures cells

Lyophilization

Front 28

High pressure

Back 28

Denatures proteins

Front 29

Desiccation

Back 29

prevents metabolism

Front 30

Osmotic pressure

Back 30

Causes plasmolysis - High salt or sugar levels

Front 31

Radiation

Back 31

Damages DNA.

Front 32

Ionizing radiation

Back 32

X rays gamma rays, electron beams

Front 33

Nonionizing radiation

Back 33

UV

Front 34

Microwaves

Back 34

Kill by heat, not especially antimicrobial

Front 35

Principles of effective disinfection

Back 35

Concebtration of disinfectant, Organic matter, pH, Time

Front 36

Evaluation of a disnfectant

Back 36

Diluation test

1. Metal rings dipped in test bacteria are dried.

2. Dried cultures are placed in disinfectant for 10 min at 20C

3. Rings are transferred to culture media to determine whether bacteria survived treatment

Front 37

Phenotics

Back 37

Lysol

Front 38

Bisphenols: Hexachlorophene, Triclosan

Back 38

Soaps and toothpast - disrupt plasma membranes

Front 39

Biguanides: Chlorhexidine

Back 39

Disrupt plasma membrane.

Surgical hand scrubs when combined with alocohol

Microbial control skin/mucous membrane up to 6 hours

Front 40

Halogens: Iodine, chorline

Back 40

Oxidizing agents

Bleach is hypochlorous acid

Front 41

Alochols: Ethanols, isopropanol

Back 41

Denature proteins, dissolve lipids

Not good for wounds-coagulated

Skin degermination

Front 42

Heavy Metals: Ag, Hg, and Cu

Back 42

Oligodynamic action - metals exerting antimicrobial activityy ex. Silver nitrate solution

Denature proteins

Front 43

Surface-active agents or surfactants

Back 43

Decrease surface tension molecules

Front 44

Soap

Back 44

Degerming

Front 45

Acid-anionic detergents Dairy industry

Back 45

Santinzing

Front 46

Quarternary ammonium compounds, Cationonic detergents, Used in moutwash

Back 46

Bactericidal, Denature proteins, disrupt plasma membrane

Front 47

Chemical food preservatives

Back 47

organic acids

Nitrite

Antibiotics

Front 48

Organic Acids

Back 48

Inhibit metabolism

Sorbic Acid, Benzoic acid, and calcium propionate

Control molds and bacteria in foods and cosmetics

Front 49

Nitrite

Back 49

Prevents endospore germination used in meat

Front 50

Antibiotics

Back 50

Nisin and natamycin prevent spoilage of cheese

Front 51

Aldehydes

Back 51

Inactivate proteins by by cross linking with funcitonal groups

Front 52

Gaseous sterilants

Back 52

Denature proteins

Ethylene oxide

Front 53

Peroxygens

Back 53

Oxidzing agents

O3, H2O2, peracetic acid

Benzoyl peroxide

Front 54

Most Resistant Microbe

Back 54

Prions

Front 55

Least Resistnat Microbe

Back 55

Viruses with lipid envelops