Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology > Sterilization And Disinfection > Flashcards

Sterilization And Disinfection Flashcards

(105 cards)

Start Studying
1
Q

Sterilization definition

A

Removal of pathogens including spores

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

Disinfection definiton

A

Removal of Pathogens but not spores

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

Asepsis definition

A

To make body surface/skin/wound free of mirco-organisms

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

Sterilization methods are divided into

A

Physical
Chemical

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

Physical Sterilization methods includes

A

Heat
Filtration
Radiation

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

Chemical sterilization methods includes

A

Alcohol
Aldehydes
Phenols
Halogens
Oxidizing agents
Plasma sterilization
Gas sterilization
Heavy metal salts
Surface acting agents
Dyes

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

Heat method of Sterilization is divided into

A

Dry heat
Moist heat

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

Examples of Dry heat methods

A

Candle
Flame burners
Sunlight
Hot air oven
Incinerator

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

Mechanism of Dry heat Sterilization methods

A

CODE
Charring
Oxidative damage
Denaturation of proteins
Elevation of electrolytes

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

Hot air oven temperature and duration

A

160°C for 2 hr
For every 10° increase in temperature - time should be decreased by half
For Ex. 170°C × 1hr, 180°C x 30 min

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

Hot air oven is used to sterilize

A

Glasswares
Cotton swabs
Wax, oils, powder gels
Dusting powder
Greasy paraffin wax
Metallic (sharp and non sharps)

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

Physical control of Hot air oven

A

Temperature monitoring by thermocouples

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

Chemical control of Hot air oven

A

Brownies tube (green spot)

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

Biological control of Hot air oven is done by

A

C. Tetani or Bacillis subtilis/atropheus

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

Incinerator is used for sterilization of

A

Hospital waste
Human anatomical waste
Animal carcasses
Expired Cytotoxic drugs

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

Temperature maintained in Incinerator

A

2 chambers - 700-800°C and 1000-1100°C

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

Mechanism of Moist heat Sterilization

A

Coagulation and denaturation ot proteins

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

Which Heating sterilization method is considered better - Dry or Moist heat

A

Moist heat

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

Moist heat Sterilization methods classification on basis of temperature

A

1) Below 100°C - IPL100 - Inspissation, Pasteurisation, Vaccine water bath
2) At 100°C - BAT - Boiling and Tyndalisation
3) Above 100°C - Autoclave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Methods or Milk Pasteurisation

A

Holder method
Flash method
Ultra high temperature method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Holder method of milk Pasteurisation temperature and duration

A

63°C for 30 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Temperature and duration of Flash method of Milk Pasteurisation

A

72°C for 20 seconds - Rapidly cool it to <13°C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Ultra high temperature method of Milk Pasteurisation

A

149°C for 1-2 sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which method of Milk Pasteurisation is better

A

Flash method as it kills Coxiella brunetti

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Tests for efficacy of Pasteurisation
1) Phosphatase test - On adding substrate - no color change (enzymes denatured) 2) Coliform test - No growth on MacConkey agar
26
Temperature and duration for Inspissation method
80°C for 20-30 min for 3 consecutive days 80-80-80
27
Inspissation method is used for sterilization of
Lowenstein Jensen media Loeffler's serum slope
28
Temperature and duration of Vaccine water bath method and uses
60°C for 1 hour Bacterial vaccines are heat inactivated
29
Temperature and duration for Boiling method
At 100°C for 15 min Doesn't kill spores
30
Temperature and duration for Tyndalisation method of Sterilization
At 100°C for 20 min for 3 consecutive days Kill spores
31
Tyndalisation Method is used for sterilization of
Used for media with gelatin/sugar TCBS XLD DCA Selenite F broth
32
Temperature and duration of Autoclave method
121°C for 15 min for 15psi To kill Prions - 134°C × 1.5 hrs
33
Control used for Autoclave
Bacillus Stearothermophilus
34
Uses of Autoclave method
Instruments (non sharps) Aprons Sutures except catgut sutures Media except LJ and LSS Sputum (prior to descending)
35
Average Pore size in Filtration method
0.22 micron
36
Types of Filtration methods
Depth filters Membrane filters
37
Depth filters include
Candle filters Seitz filters - not used Glass filters
38
Membrane filters includes
Cellulose acetate Cellulose nitrate
39
Uses of Filtration method of Sterilization
For heat sensitive substances Vaccine Antibiotics Serum Toxins Sugar solutions
40
Control of Filtration method is done by
Brevendimonas diminuta (chota chota) Serratia
41
HEPA full form and its efficacy
High efficacy particulate air filter 99.97% efficacy
42
ULPA full form and it's efficacy
Ultra low particulate air filter 99.999% efficacy
43
Types of Radiation methods of Sterilization
Ionizing (Cold radiation) Non ionising (Hot radiation)
44
Penetrating power of Ionising and Non ionizing radiation methods
Ionizing - High penetrating power Non ionizing - low penetrating power
45
Which radiation method is Sporicidal
Ionising - Sporicidal Non ionising - Bactericidal only
46
Ionising radiation includes which rays
X rays Gamma rays Cosmic rays
47
Non ionizing radiation includes which rays
UV Rays Infrared Rays
48
Uses of Non ionising radiation method
OT Fumigation Biosafety cabinet
49
Types of Alcohol used for Sterilization
Ethyl alcohol (70%) - Spirit Isopropyl alcohol (70-80%)
50
Thermometer and Stethoscope are sterilized by
Isopropyl alcohol
51
Aldehydes used for Sterilization
Formaldehyde Formalin Glutaraldehyde Ortho-phthaldehyde (OPA-Cidex)
52
Formaldehyde uses
Gas - OT Fumigation 10% NBF - For fixation of L/M
53
Formalin uses
Preserve Specimens (human) Duckering - killing bacillus anthracis spores from animal wool
54
Glutaraldehyde uses
Also known as CIDEX Used to sterilize Bronchoscope and Laryngoscope
55
Glutaraldehyde/CIDEX is activated by
Alkalinization - active for 14 days
56
Ortho-phthaldehyde (Opa-Cidex)
0.55% Solution Cystoscopes etc No activation needed and more stable More Bactericidal activity
57
Carbolic acid is first used by
Joseph Lister - Father of Antiseptic surgery
58
Mechanism of Aldehydes
Cross Linking and alkylating the molecules
59
Mechanism of Phenols for Sterilization
Protein precipitation and cell membrane damage
60
Use of Phenol
For sterilization of Sharp instruments
61
Types of Phenol
Phenol (5%) Cresol (1-3%) Lysol (2-5%)
62
Savlon consists of
Chlorhexidine + Cetrimide
63
Dettol consist of
Chloroxylenol
64
Mechanism of action of Halogens
Oxidizing agents
65
Iodine uses
Tincture iodine (2% iodine) - For skin Antiseptic Providone iodine - Betadine (iodophore) - has residual action (better)
66
Chlorine uses
1% sodium Hypochlorite - for blood spills <10ml spill - 1:100 >10ml spill - 1:10
67
Oxidizing agents includes
H2O2 - strong oxidizer, free radical injury Paracetic acid - <1% is effective for spores
68
Most effective concentration of H2O2 and concentration needed for spores
3-6% - most effective concentration 10% - needed for spores
69
Meaning of Plasma in Plasma sterilization method or Sterrad
Plasma - gaseous state containing ions and electrons
70
Process of Plasma sterilization or Sterrad
UV photons used Vacuum Low temperature H202 chemical is present
71
Advantages of Plasma sterilization method
No toxic residues Short cycle time - 75 mins
72
Uses of Plasma sterilization method
Surgical instruments eg - Arthroscope, Urethroscope etc
73
Control of Plasma sterilization method
Bacillus Stearothermophilus
74
Gas used for Gas Sterilization
Ethylene oxide
75
Mechanism of action of Gas sterilization
Microbicidal Sporicidal
76
Side effects of Gas sterilization
Highly inflammable Highly irritant Highly explosive Mix it will inert gases (3%)
77
Factors affecting Ethylene oxide
Concentration Humidity Temperature Entire cycle may take 18-24 hrs
78
Uses of Gas sterilization
Pre packed syringes Cardio pulmonary machines
79
Control of Gas sterilization
Bacillus Globigi
80
Heavy metal salts used for Sterilization
1% Silver nitrate - Opthalmia neonatarum Silver sulphonamide creams - Burns Mercury (Thiomersal) - antisera, vaccines
81
Mechanism of action of Surface acting agents in Sterilization
Lowers the surface tension
82
Anionic surface acting agents
Detergent like action Weak antimicrobial activity Ex. Soap
83
Cationic surface acting agents
Quaternary ammonium compounds More effective against Gram +ve than gram -ve bacteria Ex - Cetrimide (Savlon)
84
Amphoteric surface acting agents (TEGO Compounds)
Anionic + Cationic Detergent + antimicrobial activity Used as Antiseptic in dental procedures
85
Dyes used for Sterilization
Aniline dye Aeridine dye
86
Aniline dyes
More active against gram +ve Crystal violet Gentian violet Malachite green Not active against Tb
87
Aeridine dye
More active against Gram +ve Can act in presence of organic waste Aeriflavine Proflavin
88
Testing of disinfectant done by
Phenol coefficient test/Rideal walker test Chick martin test/Modified Rideal walker test Kelsey and Sykes test/Capacity test Kelsey and Maurer test/Inuse test
89
Phenol coefficient test/Rideal walker test
Highest dilution of disinfectant needed to kill S. Typhi broth divided by Highest dilution of phenol needed to kill S typhi broth more than 1
90
Disadvantage of Phenol coefficient test/Rideal walker test
Don't know efficacy with organic matter
91
Chick Martin test/Modified Rideal walker test
Test disinfectant in presence of organic matter (yeast, Soil, feces)
92
Kelsey and Sykes test/Capacity test
Capacity of disinfectant to be used in increasing microbiological load
93
Kelsey and Maurer test/Inuse test
Done to test for contamination of disinfectant Reality testing
94
Organisms with decreasing order of Resistance
Physics chemistry bio mein gaye small Trophy nahi final large Prize won Prions - most resistant Cryptosporidium oocyst Bacterial spores Mycobacteria Giardia cyst Small non enveloped virus Trophozoites Gram -ve bacteria Fungi Large non enveloped viruses Gram +ve bacteria Enveloped virus - most susceptible
95
Which organism is most resistant to Sterilization
Prions
96
Which organisms are most susceptible to Sterilization
Enveloped virus
97
Spaulding classification
Critical device Semi critical device Non critical device Non critical surfaces/medical equipments
98
Critical device examples and disinfection
Penetrate/Enter sterile devices High level disinfectant/chemical sterilant
99
Semi critical device and disinfection
Come in contact with mucus membrane HLD
100
Non critical devices and disinfection
Come in contact with skin Intermediate/LLD
101
Non critical surfaces/medical equipments and disinfection
Computer,desks,tables LLD
102
Intermediate level disinfectant includes
Isopropyl alcohol Iodophore Phenol
103
Low level disinfectant includes
Chlorhexidine Quaternary ammonium compounds
104
Sporicidal agents
EFGHAPPPT Ethylene oxide Formaldehyde Glutaraldehyde H202, Hot air oven, 1% Hypochlorite Autoclave Per acetic acid Plasma sterilization O-pthalic acid Tyndalisation
105
Sterilization of Prions
Critical device - Treat it with 1N NaOh and 121°C for 30 min then routine Sterilization

Microbiology (37 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions