Controlling Microbial Growth

Question 1

sepsis

Answer 1

bacterial contamination

Question 2

asepsis

Answer 2

absence of significant contamination
- aseptic technique used in labs/surgery

Question 3

sterilization

Answer 3

removing and destroying all microbial life

Question 4

commercial sterilization

Answer 4

killing C. botulinum endospores from canned goods

Question 5

disinfection

Answer 5

destroying harmful microorganisms

Question 6

antisepsis

Answer 6

destroying harmful microorganisms
from living tissue

Question 7

degerming

Answer 7

the mechanical removal of microbes
from a limited area

Question 8

sanitization

Answer 8

lowering microbial counts to safe levels

Question 9

biocide

Answer 9

treatments that kill microbes

Question 10

bacteriostasis

Answer 10

inhibiting, not killing microbes

Question 11

death curve

Answer 11

display the logarithmic decline of living microbes exposed to a method of microbial control

Question 12

physical methods of microbial growth control

Answer 12

• 1.Heat
• 2. Filtration
• 3. Low Temperatures
• 4. High Pressure
• 5. Desiccation
• 6. Osmotic Pressure
• 7. Radiation

Question 13

moist heat sterilization

Answer 13

boiling, free-flowing steam, autoclave

Question 14

heat

Answer 14

denatures enzymes (proteins) causing changes in shape to make them ineffective

Question 15

thermal death point

Answer 15

the lowest temperature at which all cells in liquid culture are killed in 10 min

Question 16

thermal death time

Answer 16

minimal time for all bacteria in a liquid culture to be killed at a
particular temperature

Question 17

decimal reduction time

Answer 17

minutes it takes to kill 90% of the population (a 1-log decrease in the total population) when exposed to a specific microbial control protocol at a given temperature

Question 18

autoclave

Answer 18

steam under pressure
* 121 C at 15 psi for 15 min
* Kills all organisms and endospores
* Steam must contact the item’s surface
* Test strips are used to indicate sterility

Question 19

pasteurization

Answer 19

reduces spoilage organisms and pathogens without ruining taste
- does not sterilize
High temp. @ certain amt of time

Question 20

equivalent treatments of pasteurization

Answer 20

(HTST) high temp. short time- 72 C 15 sec
- milk found on shelf

(UHT) ultra-high temp.- 140 C for 4 sec
- Found in fridge

Question 21

thermoduric

Answer 21

• these organisms survive pasteurization
• typically not harmful

Question 22

dry heat sterilization

Answer 22

flaming, incineration, hot air sterilization (oven)

Question 23

flaming

Answer 23

completely kills microorganisms
- used in lab to flame a loop

Question 24

incineration

Answer 24

creates hot environment

Question 25

dessication

Answer 25

absence of water prevents metabolism

Question 26

filtration desiccation

Answer 26

Passage of substance through a screenlike material * Used for heat-sensitive materials NOT heat-sensitive bacteria - used when certain chemicals want to be kept - vacuum can be used to speed up the process

Question 27

radiation

Answer 27

cause damage to DNA

Question 28

ionizing radiation

Answer 28

(x-rays, gamma rays, electron beams) Ionizes water to create reactive hydroxyl radicals

Question 29

nonionizing radiation

Answer 29

(UV 260 nm) Damages DNA by creating thymine dimers

Question 30

microwaves

Answer 30

Kill by heat; waves themselves are not antimicrobial

Question 31

chemical methods of microbial growth

Answer 31

Concentration of disinfectants Organic matter PH Time

Question 32

phenols

Answer 32

used to be used in surgery Now used in mouth Phenol ring

Question 33

triclosan

Answer 33

Added to liquid soaps but realized adding the antibiotic wasn't more effective - Harmed the environment and could cause allergic reactions - Rise in antibiotic resistance; FDA banned it in 2016

Question 34

heavy metals

Answer 34

Bind to enzymes, inhibiting their function - Ions, most are damaging, used on inanimate objects - (EX) Copper: door handles, utensils - Inhibit microbial growth (antimicrobial)

Question 35

betadines

Answer 35

Topical antiseptic before surgery - Solution of modified iodine (iodophor) - Releases iodine very slowly onto skin=effective longer

Question 36

chloramines

Answer 36

Disinfect drinking water (in emergencies) - Can be irritating to human tissues Derived from ammonia by the replacement of one hydrogen atom with a chlorine atom - Releases chlorine over time

Question 37

alcohols

Answer 37

Rapidly denatures proteins and dissolves lipids in bacteria and fungi No effect on endospores and nonenveloped viruses - isopropyl and ethyl alcohol

Question 38

isopropyl alcohol

Answer 38

related molecular structure and is another commonly used disinfectant 

Question 39

ethyl alcohol

Answer 39

the intoxicating ingredient found in alcoholic drink, and is also used commonly as a disinfectant

Question 40

soap

Answer 40

Surfactants disrupt water tension so everything mixes - Soaps are the salts of fatty acids that have the ability to emulsify lipids - Interact with water through their hydrophilic head and lipid at their hydrophobic tails - Degermer NOT an antiseptic

Question 41

quats

Answer 41

Hydrophobic nonpolar carbon chain Nitrogen has four bonds Stronger than soaps: disinfectants - Able to infiltrate the phospholipid plasma membranes of bacterial cells and disrupt their integrity

Question 42

use dilution test

Answer 42

Used to determine a chemical's disinfection effectiveness on an inanimate surface Different dilutions on different surfaces

Question 43

in use test

Answer 43

To determine whether an actively used disinfectant in a clinical setting microbially contaminated Is something growing in something currently in use

Question 44

disk-diffusion method

Answer 44

Filter paper disks are soaked in a chemical and placed on a plated culture Look for "zone of inhibition" around disks after incubation IF THERE IS NO growth around disk of disinfectant then it isn't working Microbe is more resistant to a drug/chemical Used to determine effectiveness of chemical agents against a particular microbe

Question 45

osmotic pressure

Answer 45

Uses salts and sugars to create a hypertonic environment Causes plasmolysis

Question 46

which is more sensitive (gram-neg/gram-pos)

Answer 46

gram-positive