Chapter 7-Control of Microbe Growth Flashcards Preview

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Flashcards in Chapter 7-Control of Microbe Growth Deck (91):
1

refers to microbial contamination

sepsis

2

the absence of significant contamination

asepsis

3

aseptic surgery techniques prevent what?

microbial contamination of wounds

4

removing all microbial life

sterilization

5

killing C. botulinum endospores

commercial sterilization

6

C botulinum endospores

deadly toxins

7

removing pathogens (vegetation)

disinfection

8

removing pathogens from living tissue

antisepsis

9

removing microbes from a limited area

degerming

10

lowering microbial counts on eating utensils

sanitization

11

killing microbes

biocide/germicide

12

inhibiting, not killing, microbes

bacteriostasis

13

stopping from dividing

bacteriostasis

14

growth is measured by _____ and ______ of the number of cells

generations, log10

15

refers to doubling over time (binary fission)

genertion

16

a functional representation of generation of generations over time

log

17

one log decrease= ____ of population killed

90%

18

effectiveness of antimicrobial treatment depends on

-number of microbes
-environment
-time of exposure
-microbial

19

Large populations take _____ to kill

longer

20

_____ populations are killed more quickly

small

21

a population is called a ____

load

22

______ environments increase effectiveness

warm

23

____ environments decrease effectiveness

cool

24

fats and proteins create a _____ to treatments

barrier

25

actions of microbial control agents

alteration of membrane permeability
damage to proteins
damage to nucleic acid

26

leaking of cellular content
interferes with growth

alteration of membrane permeability

27

heat and chemicals can denature protein by breaking bonds

damage to proteins

28

DNA or RNA damage

damage to nucleic acids

29

extended exposure increases effectiveness

time of exposure

30

endospores and capsules resistance to treatment and protecting of the organism

microbial characteristics

31

lowest temperature a which all cells in a culture are killed in 10 minutes

thermal death point

32

time during which all cells in a culture are killed

thermal death time

33

minutes to kill 90% of a population at a given temperature

decimal reduction time

34

moist and heat _____

proteins

35

steam under pressure

autoclave

36

moist, heat, and autoclave can ____ microbe

kill

37

reduces spoilage organisms and pathogens

pasteurization

38

70c for 15 sec

high temperature short time

39

140c for less than 1sec

ultra high temperature

40

63c for ____

30 minutes

41

equivalent treatments for pasteurization

63 for 30min
72c for 15sec
140c for less than 1sec

42

kills by oxidation

dry heat sterilization

43

how to kill by oxidation

dry heat
flaming
incineration
hot air sterilization

44

equivalent to dry heat sterilization

hot air at 170c for 2hrs
autoclave at 121c for 15min

45

removes microbes > 0.3 nanometer

HEPA

46

removes microbes > .22 nanometer

membrane filtration

47

most common size of microbes

.22 nanometer

48

what size microbe retains viruses

.01 nanometer

49

low temperature
high pressure
desiccation
osmotic pressure

physical methods of microbial control

50

inhibits microbial growth

low temperature- can be refrigeration, deep freezing, lyophilization (drying)

51

denatures proteins

high pressure

52

prevents metabolism

desiccation

53

causes plasmolysis

osmotic pressure

54

xrays, gamma rays, electron beams

ionizing radiation

55

ionizes water to release OH
damages DNA

ionizing radiation

56

UV, 260nm
damages DNA

nonionizing radiation

57

kill by heat, not especially antimicrobial

microwaves

58

4 principles of effective disinfection

concentration of disinfectant
organic matter
pH
Time

59

most common disinfectant

bisphenol and phenol

60

disrupt plasma membrane synthesis of staphylococcus and streptococcus species

hexaclorophene bisphenol

61

disrupt plasma membrane synthesis or Gram

hexaclorophene triclosan

62

found in antimicrobial/ antibacterial liquid soap

hexaclorophene triclosan

63

Lysol

hexaclorophene bisphenol/ phenol

64

halogens

iodine and chlorine

65

in aqueous alcohol

iodine-tinctures

66

in organic molecules

iodine-iodophers

67

alter protein synthesis and membrane

iodine

68

hypochlorous acid (HOCl)

Chlorine-Bleach

69

chlorine + ammonia

Chlorine- Chloramine

70

oxidizing agents (removal or loss of electrons

Chlorine

71

Alcohols

Ethanol, Isopropanol

72

denature proteins
dissolve lipids
require water (70% EtOH)

alcohol-ethanol/isopropanol

73

Heavy Metals

Ag, Hg, Cu, Oligodynamic action

74

silver nitrate may be used to prevent gonorrheal ophthalmia neonatorum

Ag, Hg, Cu

75

silver sulfadiazine used as a topical cream on burns

Ag, Hg, Cu

76

Copper sulfate is an algicide

Ag, Hg, Cu

77

denature proteins

oligodynamic action

78

degerming or physically removing microbes

soap

79

sanitizing

acid-anionic detergents (negatively charged)

80

bactericidal
denature proteins
disrupt plasma membrane
common in household cleaners

quaternary ammonium compounds (cationic detergents)

81

organic acids
nitrites

chemical food preservatives

82

-inhibit metabolism of fungus and bacteria
-sorbic acid, benzoic acid, & calcium propionate
-control molds and bacteria in foods and cosmetics

organic acids

83

-prevents endospore germination
-Clostridium and Bacillus

Nitrites

84

-inactive proteins by cross linking with functional groups
(-NH2, -OH, -COOH, -SH)
-use medical equipment (glutaraldehyde, formaldehyde, & orthophthalaldehyde)

aldehydes

85

denature proteins
use liquid, heat sensitive material (ethylene oxide)

gaseous sterilants

86

-oxidizing agents
-use contamination surfaces and skin (antiseptics)
--- O3, H2O2, peracetic acid

peroxygens

87

metal rings dipped in test bacteria are dried

dilution test

88

dried cultures are placed in disinfectant for 10 minutes at 20c

dilution test

89

rings are transferred to culture media to determine whether bacteria survived treatment

dilution test

90

plate bacteria, place disks dipped in disinfectant and incubate, measure zone of inhibition

disk diffusion method

91

zone on plate where no bacteria can grow

zone of inhibition