Ch.7

Question 1

Sepsis

Answer 1

microbial contamination on/in tissue

Question 2

Asepsis

Answer 2

absence of contamination on/in tissue

Question 3

Sterilization-

Answer 3

removing all bacterial life

Question 4

Commercial sterilization

Answer 4

killing specific methods to kill C. Botulinum endospores (used in the canning industry)

Question 5

Disinfection

Answer 5

removing pathogens on inert surfaces or substance (cleaning table)

Question 6

antisepsis

Answer 6

removing pathogens from living tissue

Question 7

degerming

Answer 7

removing microbes from a limited area (hand washing)

Question 8

Sanitization

Answer 8

lowering microbial counts on eating utensils (to safe public health levels)

Question 9

Biocide/germicide

Answer 9

killing microbes

Question 10

bacteriostasis

Answer 10

inhibiting, not killing, microbes

Question 11

Effectiveness of treatments depends on

Answer 11

Number of cells,
Environment (temp, biofilms,
Time of exposure
Specific characteristics

Question 12

How are microbes damaged?

Answer 12

Alteration of membrane Permeability
Damage to proteins
Damage to nucleic acids

Question 13

TDP and TDT

Answer 13

Thermal death point (TDP): lowest temp at which all cells in a culture are killed in 10 min, Thermal death time (TDT): minimum time at which all cells in a culture are killed

Question 14

Moist heat sterilization

Answer 14

Moist heat denatures proteins, almost all viruses, fungi die in 10 min

Question 15

Autoclave

Answer 15

is steam under pressure
Steam at 100 degrees under 15 psi above sea level gives a temp of 121 degrees
Everything is destroyed at 15 min (endospores)

Question 16

Pasteurization

Answer 16

Reduces spoilage organism and pathogens

63 C for 30 min

Question 17

High temp short-time

Answer 17

72 C for 15 sec used in US

Question 18

Ultra high temperature

Answer 18

140C for <1 sec held for 3 sec in a holding tube before cooling used in europe.

Question 19

Dry heat sterilization

Answer 19

Dry heat

Flaming, incineration,, hot-air sterilization

Question 20

HEPA

Answer 20

a filtration method that removed microbes >0.30 µm

Question 21

Membrane filtration

Answer 21

removes microbes >0.22 µm, also has other sized filters, some can remove viruses

Question 22

Equivalent treatments

Answer 22

equivalent treatments Different methods that have the same effect on controlling microbial growth

Question 23

Physical methods of microbial control

Answer 23

Low temp inhibits microbial growth
Fridge, deep freezing, lyophilization (freezing and dehydration under vacuum. High pressure denatures proteins
Desiccation prevents metabolism
Osmotic pressure causes plasmolysis

Question 24

Ionizing radiation

Answer 24

( x rays, gamma rays, electron beams,)
Ionizes water to release OH
Damages DNA

Question 25

Non Ionizing radiation (UV)

Answer 25

Damages DNA | Microwaves kill by heat, not especially antimicrobial

Question 26

What are chemical controls weak against?

Answer 26

They are hard to kill endospores, mycobacteria, and fungi are difficult to treat with chemicals

Question 27

Principles of effective disinfection

Answer 27

Concentration of disinfectant Organic matter Ph Time

Question 28

Biocide

Answer 28

kills living things

Question 29

Use-Dilution test-

Answer 29

the standard on how effective disinfectants and antiseptics are. MEtal rings are dipped in bacteria, dired, then placed in disinfectant for 10 mins. Then transferred to culture media to see if bacteria survived treatment

Question 30

Disk-diffusion test-

Answer 30

putting disk on agar to see if there is a zone of inhibition

Question 31

Phenol and phenolics

Answer 31

disrupt plasma membranes and denatures proteins (Lysol) Phenol and O-phenylphenol

Question 32

Biphenols

Answer 32

interrupt fatty acids synthesis

Question 33

Biguanides

Answer 33

disrupt membranes, used for control on skin, can be a surgical scrub Broad spectrum, affects bacteria and fungi and some viruses Not effective against endospores, mycobacteria, protozoal cysts

Question 34

Halogens

Answer 34

iodine , vegetative bacteria, some endospores, viruses and fungi Chlorine - targests bacteria, viruses, some parasites, endospores Bleach and oxidizing agents

Question 35

Alcohols

Answer 35

ethanol, isopropanol , targets bacteria, fungi not endospores

Question 36

Heavy metals

Answer 36

Ag, Hg, Cu silver, mercury, copper

Question 37

Oligodynamic action

Answer 37

(very little needed to be effective) denatures proteins (think heavy metals)

Question 38

surfactants

Answer 38

are Surface-Active agents

Question 39

Soap

Answer 39

a surfactant used for degerming

Question 40

Organic acids

Answer 40

inhibit metabolism, controls molds and bacteria in foods and cosmetics

Question 41

Nitrite

Answer 41

prevent endospore germination

Question 42

Aldehydes-

Answer 42

inactivate proteins by cross linking with functional groups. Medical equipment

Question 43

Gaseous Sterilants

Answer 43

dentaure proteins

Question 44

Plasma

Answer 44

generate free radical destroy microbes used in tubular instruments (laparoscopic, arthroscopic tools).

Question 45

Peroxygens

Answer 45

oxidizing agents, used on contaminated surfaces