Ch.7 Control of microbial growth

Question 1

sepsis

Answer 1

Microbial contamination

Question 2

sterlization

Answer 2

removal of all microbial life

Question 3

disinfection

Answer 3

removal of pathogens (non living)

Question 4

degerming

Answer 4

remove of microbes from a limited area

Question 5

asepsis

Answer 5

absence of significant contamination

Question 6

comercial sterilization

Answer 6

limited heat treatment.

kills C. botulinim

Question 7

antisepsis

Answer 7

removal of pathogens from living tissue

Question 8

sanitation

Answer 8

lower microbial counts on eating utensils

Question 9

factor affecting antimicrobial treatment

Answer 9

1. number of microbes
2. enviroment (organic matter, temperature, pH, biofilms)
3. time of exposure
4. Microbial characteristics

Question 10

Actions of microbial Control Agents

Answer 10

1. alternation of plasma membrane permeability
2. damage to proteins
3. damage to nucleic acids

Question 11

alternation of membrane permeability

Answer 11

damage to lipids or proteins of the plasma membrane by antibacterial agents causes cellular contents to leak, interfering with the growth of the cell

Question 12

damage to proteins and Nucleic acid

Answer 12

damage of by heat, radiation, or chemicals is sufficiently lethal to cell, cell can no longer replicate, nor carry out metabolic functions ( synthesis of enzymes).

Question 13

physical methods of microbial growth

Answer 13

heat
filtration
low temperature
high pressure
osmotic pressure
radiation

Question 14

heat

Answer 14

physical methods of MC
moist heat
pasteurization

Question 15

moist heat

Answer 15

heat-physical method of MC
denature proteins
_Autoclave_steam under pressure- most preferred method of sterilization.

Question 16

pasteurization

Answer 16

heat-physical method of MC
reduces spoilage and pathogens, but does not sterilize
high temp short time: 72C for 15 sec
ulta high temp: 140 C for < 1 sec

Question 17

dry heat sterilization

Answer 17

heat- physical methods of MC
kills by oxidation 
direct flaming
incineration
hot air sterilization

Question 18

filtration

Answer 18

Physical method Of MC
used to sterilize heat sensitive ( heat liable) vaccines, proteins, etc.
passage of liquid or gas through a screen like material with pores small enough to retain microorganisms.

Question 19

low temperature

Answer 19

physical methods of MC
refrigeration
deep freezing
lyophilization
inhibits microbial growth 
slow freezing harmful due to ice crystal damage

Question 20

high pressure

Answer 20

physical method of MC
denatures proteins ( in some instances it can sterilize on its own growth

Question 21

osmotic pressure

Answer 21

physical methods of MC
causes plasmolysis
use of high concentration of salts and sugars to preserve food.

Question 22

radiation

Answer 22

physical methods of MC
kills bacteria depending on wavelenght, intensity, and duration.
damages DNA
two types
ionization and non ionization

Question 23

Ionization

Answer 23

sterilizes by x rays, gamma rays, electron beam.

Question 24

nonionizing

Answer 24

longer wavelenght than ionization radiation

uses UV light.

Question 25

Chemical methods of MC

Answer 25

1. principle of effective disinfection 2. concentration of disinfectant 3. organic matter 4. pH 5. Time

Question 26

types of Disinfectants

Answer 26

``` phenol bisphenols biguanides alcohols Heavy metals surface active agents ( surfactants) ```

Question 27

phenol (lysol) (disinfectant)

Answer 27

irritating to cells & irritating smell | Phenolics- developed to be more effective, odorless, & less irritating to human cells.

Question 28

bisphenols (disinfectant)

Answer 28

disrupt plasma membrabe | hexachlororphene, triclosan

Question 29

Biguanides (disinfectant)

Answer 29

disrupt plasma membrane. | Clorhexidine ( PhisoHex, surgical hand scrub)

Question 30

Alcohols (disinfectant)

Answer 30

effective killing bacteria and fungi but not endospores and non enveloped virus. Ethanol Isopropanol pure alcohol worse than 70% denatures ( requires water) proteins, dissolve lipids

Question 31

Heavy metals (disinfectant)

Answer 31

``` oligodynamic action denatures proteins oligo= few silver nitrate coper sulfate mercurochrome merthioalte ```

Question 32

silver nitrate

Answer 32

disinfectant | put in newborn's eyes to prevent Nisseria Gonorrhoeae infections

Question 33

coper sulfate

Answer 33

disinfectant | use to kill algae in pounds

Question 34

mercurochrome & merthiolate

Answer 34

disinfectants rome- Monkey blood both used in vaccines

Question 35

surface active reagents

Answer 35

disinfectants surfactants decrease surface tension among molecules of a liquid. soap good at degerming, but least effective at disinfecting.

Question 36

Chemical food preservatives

Answer 36

control molds and bacteria on foods and cosmetics 1. Organic acids 2. Nitrate 3. Antibiotics

Question 37

Organic acids

Answer 37

``` Chem. food Pre. inhibit metabolism judge to be safe in foods sorbic acid benzoic acid calcium propionate ( sodium propionate) ```

Question 38

chemical sterilants

Answer 38

Aldehydes inactivate proteins Glutaraldehyde ( safer than formaldehyde) formaldehyde ortho-phtalaldehyde

Question 39

Gaseous sterilants

Answer 39

``` denature proteins use heat sensitive material sterilize w/o heat hosp. use on mattresses are suspected carcinogens ethylene oxide ```