Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Lecutre 9 > Flashcards

Lecutre 9 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are the 4 results of methods of microbial control used outside of the body?

A

Sterilization

disinfection

decontamination (also called sanitization)

antisepsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Who are the targets of microbial control?

A

Primary targets of microbial control are microorganisms capable of causing infection or spoilage in the environment or on the human body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are considered the most resistant microbes?

A

bacterial endospores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the goal of sterilization?

A

The goal of any sterilization process is the destruction of bacterial endospores
any process that kills endospores will invariably kill all less resistant microbial forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In microbial control what is the difference between an agent and process?

A

agent- something that aids in microbial control

process- is how microbes are controlled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Is sterilization and disinfection an agent or process?

A

processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Is bactericide an agent or process?

A

agent, chemical that destroys bacteria except for those at the endospore stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Is fungicide an agent or process?

A

agent, chemical that can kill fungal spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Is virucide an agent or process?

A

agent, chemical known to inactivate viruses, especially on living tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Is sporicide an agent or process?

A

an agent capable of destroying bacterial endospores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Is germicide/microbicide an agent or process?

A

agent, chemical agents that kill microorganisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is sepsis?

A

the growth of microorganisms in the blood and other tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is asepsis?

A

Process, any practice that prevents the entry of infectious agents into sterile tissues and thus prevents infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are antispetics?

A

process, chemical agents applied directly to exposed body surfaces (skin and mucous membranes), wounds, and surgical incisions to prevent vegetative pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Is bacteristatic an agent or process?

A

agent, chemical agents that prevent the growth of bacteria on tissues or on objects in the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Is fungistatic an agent or process?

A

agent, chemicals that inhibit fungal growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is microbial death?

A

permanent termination of an organism’s vital processes
microbes have no conspicuous vital processes, therefore death is difficult to determine

permanent loss of reproductive capability, even under optimum growth conditions has become the accepted microbiological definition of death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the factors the affect the death rate?

A

begins when a certain threshold of microbicidal agent is met

death continues in a logarithmic manner as the time or concentration is increased

active cells tend to die more quickly than less metabolically active cells

Eventually, a point is reached at which survival of any cells is highly unlikely; this point is equivalent to sterilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the cellular targets of heat and radiation?

A

they target the widest range of microbes because they are the least selective

20
Q

Are drugs selective or not?

A

They are very selective and only target a single cellular component

21
Q

What are the cellular targets of physical and chemical agents?

A

cell wall

cell membrane

cellular synthetic processes

proteins

22
Q

Are elevated temperatures microbicidial or microbistatic?

A

microbicidial

23
Q

Are lower temperatures microbicidial or microbistatic?

A

microbistatic

24
Q

Is moist heat or dry heat hotter?

A

dry heat

25
Q

What is Thermal death time (TDT)?

A

shortest length of time required to kill all test microbes at a specified temperature

26
Q

What is Thermal death point (TDP)?

A

the lowest temperature required to kill all microbes in a sample in 10 minutes

27
Q

What is autoclave? pressure? temp? time?

A

steam under pressure (15 psi)
Can reach 121ºC
Steam driven into materials, kills microbes
Can adjust time depending on what is being autoclaved
Only for heat-resistant materials

28
Q

What is intermittent sterilization?

A 
Aka tyndallization
Reservoir of boiling water
Expose to steam 30-60 min
Incubate 23-24 hrs (spore germination)
Repeat steam treatment
Do this for 3 days in a row
Doesn’t get rid of highly resistant spores that may not germinate in 3 days
29
Q

Does pateruization sterilize milk?

A

No it affects viruses and vegetative cells

30
Q

What does boiling do to microbes?

A

30 minutes will kill most non-sporeforming pathogens; easy to contaminate when removing

31
Q

What does incineration do to microbes?

A

Flame, electric coil
Bunsen burner 1,870ºC
Furnace up to 6,500ºC
Fast and effective, but only on very heat stable material

32
Q

What does baking do to microbes?

A

Hot air oven
150-180ºC, 2-4 hrs
Glassware, metals, powders, oils
No liquids - evaporation

33
Q

What is the benefit of cold treatment for microbes?

A

Principal benefit of cold treatment is to slow growth of cultures and microbes in food during processing and storage

Cold merely retards the activities of most microbes

34
Q

What do the temperatures of -70 to -135 celcius do for microbes?

A

can preserve cultures of bacteria, viruses, and fungi for long periods

35
Q

What do psychophiles have to cold temperatures?

A

Psychrophiles grow slowly at freezing temperatures and can secrete toxic products

36
Q

what are the pathogens that are able to survive several months in the fridge?

A

Staphylococcus aureus

Clostridium species

Streptococcus species

Salmonella

yeasts, molds, and viruses

37
Q

What is desiccation?

A

vegetative cells directly exposed to normal room temperature gradually become dehydrated

38
Q

What is lyophilization?

A

combination of freezing and drying

method of preserving microorganisms in a viable state for many years

pure cultures are frozen instantaneously and exposed to a vacuum that removes water, avoiding the formation of ice crystals

39
Q

What is radiation?

A

Energy emitted from atomic activities and dispersed at high velocity through matter or space
gamma rays

X rays

ultraviolet radiation (thymidine dimers, next slide)

40
Q

is osomotic a sterlizing technique?

A

NEVER

41
Q

What are aqueous solutions?

A

chemicals dissolved in pure water as the solvent

42
Q

What are tinctures?

A

chemicals dissolved in pure alcohol or water-alcohol mixtures

43
Q

How are germicides evaluated?

A

in terms of their effectiveness in destroying microbes in medical and dental settings
high-level germicides kill endospores and can be used as sterilants

intermediate-level germicides kill fungal, but not bacterial spores, resistant pathogens, and viruses

low-level germicides eliminate only vegetative bacteria, vegetative fungal cells, and some viruses

44
Q

What is the percentage of ethyl alcohol?

A

70

45
Q

What is the percentage of hydrogen peroxide ?

A

3

46
Q

How and why are dyes used as antimicrobial agents?

A

active against gram-positive bacteria and fungi

sometimes incorporated into solutions and ointments to treat skin infections

limited application because they stain and have a narrow spectrum of activity

47
Q

How and why are acids and alkalis dyes used as antimicrobial agents?

A

very low or very high pH can destroy or inhibit microbial cells

limited in applications due to their corrosive, caustic, and hazardous nature

ammonium hydroxide used in detergents, cleaners, and deodorizers

organic acids used in food preservation

Microbiology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions