Physical and Chemical Control of Microbes

Question 1

Microbes with least level of resistance

Answer 1

vegetative bacterial; most likely to be killed

Question 2

Microbes with moderate levels of resistance

Answer 2

protozoan cyst and fungal spores

Question 3

Microbes with high levels of resistance

Answer 3

bacterial endospores and prions

Question 4

Sterilization

Answer 4

any process that destroys all life and inactivates all viruses and prions

Question 5

Sterile

Answer 5

everything dead

Question 6

Inactivated

Answer 6

mostly/partly sterile

Question 7

-icide

Answer 7

to kill (fungicide)

Question 8

-statics

Answer 8

prevent growth; killing is not the goal (bacteriostatics, fungistatic)

Question 9

Disinfectant

Answer 9

process of destroying vegetative pathogens/endospores and remove toxic products of organisms

Question 10

Sanitization

Answer 10

removes microorganisms and debris; physical removal

Question 11

Sepsis

Answer 11

state of having microbes present (in body tissues)

Question 12

Asepsis

Answer 12

practice that prevents the entry of a microbe into tissue, body, areas

Question 13

Microbial death

Answer 13

whether or not they are capable of undergoing cell division in their optimal conditions

Question 14

How to decide method to kill microbe

Answer 14

number of organisms, nature of the organism, environmental conditions, concentration of antimicrobial agent, mode of action of the antimicrobial agent, presence of interfering organic matter or solvents things

Question 15

Number of organisms

Answer 15

more = thicker = longer time to destroy microbes

Question 16

Nature of organisms

Answer 16

microbes ability to survive

Question 17

Environmental conditions

Answer 17

temperature and pH in which you’re trying to kill the microorganisms can affect the activity of the disinfectant

Question 18

Concentration of antimicrobial agent

Answer 18

higher the concentration the better the antimicrobial agent is (except alcohol)

Question 19

Mode of action of the antimicrobial agent

Answer 19

how that antimicrobial agent attacks the microbe and knowing whether or not the microbe actually contains the structure that’s being attacked

Question 20

Presence of interfering organic matter or solvents things

Answer 20

can inhibit the action of antimicrobial agents

Question 21

Mode of action

Answer 21

against cell wall, surfactants, cellular synthesis, protein structure and function

Question 22

Action against bacterial cell wall

Answer 22

target the cell wall; compromised cell wall can allow attack of cell membrane

Question 23

Action of surfactants

Answer 23

disrupts the structural integrity of phospholipid membrane causing release of important molecules and toxins to come into cell

Question 24

Action of targeting cellular synthesis

Answer 24

targeting anything that can affect the ability for a microbe to reproduce and survive

Question 25

Action of targeting protein structure and function

Answer 25

destroys function of protein; cell wont be able to release waste, bring in nutrients, etc.

Question 26

Moist heat

Answer 26

heat that includes the use of steam (60-135C)

Question 27

Mode of action of moist heat

Answer 27

coagulates and denatures protein

Question 28

How to have steam @ temps above 100C?

Answer 28

add pressure

Question 29

Eg. of moist heat

Answer 29

autoclave, pasteurization (60-70C @ short periods), fasteurization, boiling water

Question 30

Dry heat

Answer 30

removes water needed for metabolism, denatures, incinerates (160C+)

Question 31

Eg. of dry heat

Answer 31

flame, oven

Question 32

Moist v dry heat

Answer 32

moist heat is more effective at same temps (coagulation and denaturing of proteins)

Question 33

Thermal death point

Answer 33

lowest temperature required to kill all microbes in 10 minutes

Question 34

Lyophilization

Answer 34

freeze-drying microbes/chemicals

Question 35

Lyophilized chemical

Answer 35

rehydrating freeze-dried chemicals

Question 36

Ionizing radiation

Answer 36

transmitting enough energy molecule is able to eject out of orbital and create chemical changes (gamma rays and x-ray)

Question 37

Effect of ionizing radiation

Answer 37

break covalent bonds in DNA leading to mutations

Question 38

Non-ionizing radiation

Answer 38

causes electron to enter slightly higher energy state (not creating ions)

Question 39

Effect of non-ionizing

Answer 39

lead to the formation of abnormal bonds

Question 40

Ionizing radiation mutations

Answer 40

large scale

Question 41

Non-ionizing radiation mutations

Answer 41

point mutations

Question 42

Mechanical removal of microbes

Answer 42

using filters to remove microbes from a fluid (liquid/air/water)

Question 43

Chemical agents

Answer 43

keep microbes from growing and surviving (eg. disinfectants, antiseptics, sterilizers, preservatives)

Question 44

Aqueous solution

Answer 44

pure water or water-based liquid chemical agent

Question 45

Tincture

Answer 45

antimicrobial agent that is alcohol or water alcohol-based dilution

Question 46

Ideal antimicrobial chemical agents

Answer 46

glutaraldehyde, chlorhexidine, hydrogen peroxide

Question 47

common antimicrobial chemical halogens

Answer 47

chlorine, iodine

Question 48

Mode of action for halogens

Answer 48

break disulfide bonds

Question 49

Disulfide bonds

Answer 49

bonds between two sulfur atoms that are found in proteins between two cysteine amino acids

Question 50

Amino acids that contain sulfur

Answer 50

methionine, cysteines

Question 51

What kind of bond is a disulfide bond?

Answer 51

covalent; causes permanent denaturation

Question 52

Chlorine

Answer 52

OCl-

Question 53

Hypochlorite (most common chlorine)

Answer 53

OCl

Question 54

Iodine

Answer 54

free iodine and iodophors

Question 55

Iodophors

Answer 55

iodine complexed with neutral polymers

Question 56

What do large molecules in iodophors allow?

Answer 56

slow release of the iodine into solution; allow for function and lasting effects

Question 57

Phenol

Answer 57

six carbon ring structure with double bonds in the ring structure with an attached hydroxide functional group

Question 58

Mode of action phenol

Answer 58

disrupts cell walls and it disrupts cell membranes and also precipitates proteins

Question 59

Chlorhexidine chlorexodyne

Answer 59

combination of chlorine and two phenolic rings

Question 60

Ethanol

Answer 60

two carbons with a hydroxide

Question 61

Isopropanol

Answer 61

three carbon alcohol with the hydroxide alcohol; more effective

Question 62

Mode of action for alcohols

Answer 62

concentrations 50 or higher dissolve membrane lipids and denature proteins by coagulation

Question 63

Why does 80% alcohol not coagulate?

Answer 63

not enough water

Question 64

What does alcohol do to the cell?

Answer 64

dehydrates the cell, does not kill

Question 65

Oxidizing agents

Answer 65

hydrogen peroxide and ozone

Question 66

Cationic detergents include

Answer 66

quaternary ammonium/quats

Question 67

Quats (cationic)

Answer 67

attracted to the phospholipids and be very effective at causing leaks in the cell membrane

Question 68

Mode of action metallic elements

Answer 68

bind to functional groups of proteins and inactivate them bringing metabolism

Question 69

Aldehydes

Answer 69

organic substance that contains a c-h-o functional group or an aldehyde functional group

Question 70

Eg. aldehydes

Answer 70

glutaraldehyde, formaldehyde

Question 71

Ethylene oxide

Answer 71

sterilizer when binds to DNA molecules and proteins

Question 72

Chlorine dioxide

Answer 72

strong alkylating agent reacting with functional groups in DNA and protein