Control Of Growth

Question 1

Disinfect

Answer 1

Reduce number of pathogens to safe level on inanimate objects

Example cleaning a lab bench

Question 2

antisepsis

Answer 2

Disinfect on living things,

Reduce number of pathogens to safe level on living things

Question 3

Microbiocidal

Answer 3

Kill micro organisms

Question 4

Bactericidal

Answer 4

Kills bacteria

Question 5

Viricidal

Answer 5

Kills viruses

Question 6

Fungicidal

Answer 6

Kills fungi

Question 7

Tuberculocidal

Answer 7

Kills TUberuculosis

Question 8

Microbiostatic

Answer 8

Inhibits growth,
If agent removed, growth continues

Example: refrigerator

Question 9

Bacteriastatic

Answer 9

Inhibits growth of bacteria

Question 10

Degerming

Answer 10

Mechanical removal of MO

Reduce number by brushing, flossing, hand washing, scrubbing

Question 11

Pasteurization

Answer 11

Heat used to reduce spoilage MO

And kill disease causing pathogens

Question 12

Decontaminate

Answer 12

To reduce number of MO to safe level

Question 13

Sanitize

Answer 13

Similar to disinfect used in food industry

Question 14

Mysophobia

Cypriphobia

Answer 14

Mysophobia: fear of germs
Cypriphobia: fear of getting an STD

Question 15

Factors that effect growth

Answer 15

1. Concentration of disinfectant
2. Time to work
3. Environmental conditions ( temp and PH)
4. Site/tissue to be treated
5. Sensitivity of MO
6. Microbe density
7. Real world considerations ( cost, smell, stain ect.)

Question 16

How do control agents work?

Answer 16

1. Affect cell membrane or cell wall
2. Affect DNA by mutation
3. Affect protiens

Question 17

Sterilize

Answer 17

Kill all MO

All of them including viruses and endospores

Question 18

Moist heat

Answer 18

Used to disinfect, sanitize, sterilize, pasteurize

Kills by denaturing proteins
Penetrates and water conducts heat better,

Boiling: kills but not sterilized( virus and endospores survive)

Autoclave: sterilized at 121 C and 15 psi for 15 min
(Tape is often used to insure conditions are met)
Kills endospores but not prions)
Effective on equipment that can withstand conditions

Question 19

Pasteurization

Answer 19

“Sanitize milk”
Reduce spoilage MO and kill pathogens
It is a time and temp relationship

Not sterilized (other countries do this but changes taste)

Question 20

Dry heat

Answer 20

Killing cells
Examples:direct flame (lab)
Incineration for prions and burn boxes(a very high temp)

Question 21

Low heat (cooling)

Answer 21

Decrease growth by slowing protiens down
Refrigeration : some MO grow ( listeria, Yersinia, psycotrphes)

Freezing: does not kill MOs (Bactericidal)
Slow cooling more effective than fast

Question 22

Radiation

Answer 22

UV: used to sterilize surfaces but can NOT penetrate
Mutates DNA

Ionizing radiation: high energy radiation
Causes free radical in cells that kill them
Used on medical equipment and on food (bread and hamburger)

Question 23

Filtration

Answer 23

Air filtration
Small pores trap MO
Is not sterilized
HEAP filters ( some prokaryotes and virus get through)
Rooms pressurized to keep “cleaner air in”

Membrain
Think cleaning water
Used for filtering vaccines

Question 24

Desiccation

Answer 24

Means to dry out
Think jerky or dried fruit
Important in history for survival

Question 25

Sound waves

Answer 25

Cavitation uses high frequency to creat bubbles that kill cells
Clear debris off medical equipment
Most effective on gram -

Is not sterilized or disinfected

Question 26

Osmotic strength

Answer 26

Put lots of salt or sugar in food to preserve it
Causes cells to dry out

Cultured materials
Beer, wine, yogurt

Question 27

Alcohols

Answer 27

Disrupts cell membrane of all living things
Advantage-cheap and easy
Disadvantage- evaporate, does not kill endospores,

Used to degerm skin (must be in correct concentration)

Question 28

Aldehydes

Answer 28

Affects proteins and nuclaic acid
Advantages: sporicidal and can sterilize
Disadvantage: toxic, carcinogen

Used: add as vaccine preservative, soak heat sensitive instriments

Question 29

Gases ( ethylene oxide)

Answer 29

Works on proteins
Advantage: penetrate, effective, sterilize
Disadvantage: carcinogen, explosive, highly regulated

Used to sterilize medical devices and our petri plates

Question 30

Halogens

Answer 30

Chlorine and iodine
Broad range and cheap, and fast

Disadvantage: reacts with organic compounds

Used: pools and for clean water

Question 31

Metals (silver)

Answer 31

Works by denaturing protein
Advantage: effective
Disadvantage: toxic, persist, expensive

silver for wound cleaning or eye drops
Mercury( treating material and syphilis)
Copper for algae

Question 32

Peroxide

Answer 32

Hydrogen peroxide and ozone
Advantage: fast, used on non living things, no residue
Disadvantage: can damage tissue

Uses: teach whiting, pools in Europe, surface cleaner

Question 33

Phenolic compounds (tea tree oil, pinesol)

Answer 33

Destroy PM and protiens
Advantage: first known disinfect, effective, cheep, works if organic material present

Disadvantage: smell, irritating, not great against viruses

Uses: cleaning, soap

Question 34

Quats ( surfactants)

Answer 34

Works by affecting plasma membrain
Advantage: cheap and effective
Disadvantage: takes time, endospores, mycobacterium non enveloped not effected

Uses:
Lab bench cleaner
Good on inanimate objects

Question 35

Biological control

Answer 35

Fermentation
Cultures like yogurt
Phage use ( antibiotic resistance)