Chapter 5 Flashcards
(183 cards)
1
Q
introduced methods to prevent
infection of wounds
A
Joseph Lister
2
Q
Applied what directly onto damaged tissues, where it prevented infections
A
carbolic acid (phenol)
3
Q
introduced as a surgical antiseptic
A
Listerine
4
Q
Oral antiseptic names after Lister
A
Listerine
5
Q
removal of all microorganisms
A
Sterilization
6
Q
is free of microbes including endospores and
viruses (but does not consider prions)
A
sterile
7
Q
elimination of most or all pathogens
* Some viable microbes may remain
A
Disinfection
8
Q
used on inanimate objects
A
Disinfectants
9
Q
kill bacteria
A
Bactericides
10
Q
kill fungi
A
Fungicides
11
Q
inactivate viruses
A
Virucides
12
Q
used on living tissue
A
Antiseptics
13
Q
reduce pathogens to levels considered safe
to handle.
A
Decontamination:
14
Q
examples of Decontamination:
A
Washing, use of heat or chemicals
15
Q
substantially reduced microbial population that meets accepted health standards
A
Sanitization
16
Q
process of delaying spoilage of foods and other
perishable products
A
Preservation:
17
Q
growth-inhibiting
A
bacteriostatic
18
Q
brief heating to reduce number of spoilage organisms, destroy pathogens without changing characteristics of product
A
Pasteurization
19
Q
routine control
A
washing and scrubbing with soaps and detergents
cooking
foods, cleaning surfaces, and refrigeration
20
Q
Pathogens more likely found in hospital setting.
A
healthcare-associated infections (HAIs)
21
Q
Pathogens more likely found in hospital setting are in what
A
Feces, urine, respiratory droplets, bodily secretion
22
Q
more susceptible to infection
A
Weakened patients
23
Q
are used in patient
care to prevent infection of both patients and personnel.
A
Standard Precautions
24
Q
highly transmissible or epidemiologically important
pathogen
A
Transmission-Based Precautions
25
very difficult to destroy
prions
26
prevent contamination of samples,
workers and environment
Aseptic techniques
27
For work with microbes not known to cause disease in healthy people
BSL-1
28
For work with moderate-risk microbes that cause
disease but have limited potential for transmission
BSL-2
29
Procedures for work with pathogens that cause
serious or potentially fatal disease through inhalation
BSL-3
30
Procedures for work with easily transmitted deadly
pathogens
BSL-4.
31
32
Perishables retain quality longer when
contaminating
microbes destroyed, removed, inhibited
33
most common and reliable mechanism for retaining perishables
heat treatment
34
approved to treat certain foods without altering
irradiation
35
can prevent spoilage (regulated by FDA
due to risk of toxicity)
Chemical additive
36
Ensure drinking water free of pathogens
Water Treatment Facilities
37
Choice of effective procedure depends on what numerous factors
* Type and number of microbes
* Environmental conditions
* Risk of infection
* Composition of infected item
38
Multiple highly resistant microbes
* Bacterial endospores
* Protozoan cysts and oocysts
* Mycobacterium species
* Pseudomonas species
* Non-enveloped viruses
39
40
most resistant, only extreme heat or chemical treatment destroys them
Bacterial endospores
41
resistant to disinfectants;
excreted in feces; causes diarrheal disease if ingested
Protozoan cysts and oocysts
42
waxy cell walls makes resistant to many chemical treatments
Mycobacterium species
43
resistant to and can actually grow in some disinfectants
Pseudomonas species
44
lack lipid envelope; more resistant to disinfectants
Non-enveloped viruses
45
Fraction of population what during given time interval
dies
46
is the population bigger or smaller with more time
bigger
47
Removing organisms by what reduces time to sterilize
washing
48
helps remove biofilms
scrubbing
49
gauges commercial effectiveness
Decimal reduction time
50
Time required to kill 90% of
population under specific
conditions
Decimal reduction time
51
can interfere with heat penetration, action of chemicals
Dirt, grease, body fluids
52
Microorganisms in what are more resistant
biofilm
53
can influence effectiveness
pH, temperature
54
come in contact with body tissues
Critical items
55
what level of sanitization must Critical items be
sterile
56
contact mucous membranes but do not penetrate body tissues
Semicritical instruments
57
what level of sanitization must Semicritical instruments be
Must be free of viruses and vegetative bacteria
58
contact unbroken skin only
Non-critical instruments
59
inappropriate for plastics and other sensitive items
heat
60
provides alternative, but damages some types of
plastic
Irradiation
61
cannot be used to treat moisture-sensitive material
Moist heat, liquid chemical disinfectants
62
can be used on materials that cannot withstand heat treatment
Filtration, irradiation, and high-pressure treatment
63
irreversibly denatures protein
Moist heat
64
destroys most microorganisms and viruses
boiling
65
does boiling kill endospores and sterilize
no
66
destroys heat-sensitive pathogens, spoilage
organisms
Pasteurization
67
most products classify as what kind of Pasteurization
High-temperature-short-time (HTST)
68
shelf-stable boxed juice and
milk; known as “ultra pasteurization”; packaged in sterile containers
Ultra-high-temperature (UHT)
69
used to sterilize using pressurized steam
autoclave
70
does autoclave kill endospores and sterilize
yes
71
Physical methods to Destroy Microorganisms and Viruses
steam must enter item and displace air
Tape with a heat-sensitive indicator can confirm heating
72
how to make sure steam enters item and displace air
– Place long, thin containers on their sides
– Do not close containers tightly
73
can confirm lack of microbial growth after autoclaving
Biological indicators
74
industrial-sized autoclave
retort
75
Designed to destroy Clostridium botulinum endospores
Commercial Canning Process
76
what uses retort
Commercial Canning Process
77
Cells grow in low-acid anaerobic conditions and produce
botulinum toxin
78
what endospores remain in Canned food
Endospores of some thermophiles may survive
Usually not a concern; only grow at temperatures well above normal storage
79
Less effective than moist heat; longer times, higher
temperatures necessary
Dry heat
80
a method of dry heat sterilization
Incineration
81
Oxidizes cell to ashes
Incineration
82
Used to destroy medical waste and animal carcasses
Incineration
83
example of Incineration
Laboratory inoculation loop sterilized by flaming
84
types of Filtration of fluids
Membrane filters
Depth filters
85
Small pore size (0.2 µm) to remove bacteria
Membrane filters
86
– Thick porous filtration
material (e.g., cellulose)
– Larger pores
– Electrical charges trap cells
Depth filters
87
High-efficiency particulate air (HEPA) filters remove nearly
all microbes over 0.3 micrometer from air
Filtration of air
88
radio waves,
microwaves, visible and UV light, X rays, and gamma rays.
Radiation: electromagnetic radiation:
89
are wavelength and frequency inversely or directly proportional
inversely
90
does High frequency or low frequency have more energy
High frequency
91
92
can remove electrons from atoms
Ionizing radiation
93
Destroys DNA, damages cytoplasmic membranes and
produce ROS (reactive oxygen species)
Ionizing radiation
94
– Used to sterilize heat-sensitive materials
High energy gamma-rays
95
Generally used after packing
High energy gamma-rays
96
FDA has approved for spices and dried herbs, fruits,
vegetables, and grains (insect control), pork (parasite control), and poultry, beef, lamb, and pork (bacterial control)
High energy gamma-rays
97
destroys microbes directly b y damaging DNA
Ultraviolet radiation
98
Used to destroy microbes in air, water, and on surfaces
Ultraviolet radiation
99
downsides of Ultraviolet radiation
Poor penetrating power
– Thin films or coverings can limit effect
– Cannot kill microbes in solids or turbid liquids
– Most glass and plastic block
100
heat food unevenly, so cells can survive
Microwave ovens
101
kill by generated heat, not directly
microwaves
102
Decreases number of microorganisms in commercial food products by Employs high pressure up to 120,000 psi
High Pressure Processing (HPP)
103
Products maintain color, flavor associated with fresh food
High Pressure Processing (HPP)
104
Destroys microbes by denaturing proteins and altering cell
permeability
High Pressure Processing (HPP)
105
types of moist heat
boiling
pasteurization
pressurized steam
106
types of dry heat
incineration
dry heat ovens
107
types of filtration
filtration of fluids
filtration of air
108
types of radiation
ionizing radiation
ultraviolet radiation
109
can disinfect and, in some cases, sterilize
Germicidal chemicals
110
do Germicidal chemicals react irreversibly with proteins, DNA, cytoplasmic membranes, or viral envelopes. or reversibly
irreversibly
111
useful for treating large surfaces and heat-sensitive items
Germicidal chemicals
112
types of Germicidal chemicals
* Sterilants
* High-level disinfectants
* Intermediate-level disinfectants
* Low-level disinfectants
113
destroy all microorganisms
Sterilants
114
destroy viruses, vegetative cells
High-level disinfectants
115
destroy vegetative bacteria,
mycobacteria, fungi, and most but not all viruses
Intermediate-level disinfectants
116
destroy fungi, vegetative bacteria except mycobacteria, and enveloped viruses
Low-level disinfectants
117
things to note about Germicidal Chemical
* Toxicity
* Activity
* Compatibility
* Residues: can be toxic or corrosive
* Cost and availability
* Environmental risk: Agent may need to be neutralized before disposal
118
60–80% aqueous solutions of ethyl or isopropyl alcohol
Alcohols
119
what don't Alcohols kill
endospores, some naked viruses
120
Damage membranes, denature essential proteins
Alcohols
121
Commonly used as antiseptic and disinfectant
alcohol
122
benefits of alcohol
non-toxic, inexpensive, no residue
123
limitations of alcohol
* Evaporates quickly, limiting contact time
* Can damage rubber, some plastics, and others
124
inactivates proteins and nucleic acids
Aldehydes
125
Immersion in what for 10–12 hours kills all microbial life
type of Aldehyde: 2% alkaline glutaraldehyde
126
is 2% alkaline glutaraldehyde toxic
yes
127
Effective germicide that kills most microbes quickly
type of Aldehyde: Formaldehyde
128
Used to kill bacteria and inactivate viruses for vaccines
type of Aldehyde: Formaldehyde
129
is Formaldehyde a carcinogen
yes
130
Extensive use as antiseptics that Stays on skin, mucous membranes
Biguanides
131
type of Biguanides
Chlorhexidine
132
is Chlorhexidine toxic
Relatively low toxicity
133
Destroys vegetative bacteria, fungi, some enveloped viruses
Chlorhexidine
134
what is Chlorhexidine used in
skin cream, prescription
mouthwash
135
Useful gaseous sterilant – applied with special chamber
Ethylene oxide
136
Destroys microbes including endospores and viruses
Ethylene oxide
137
Penetrates fabrics, equipment, implantable devices like Pacemakers, artificial hips
Ethylene oxide
138
Ethylene oxide is useful in sterilizing what
heat- or moisture-sensitive items
139
Ethylene oxide is used for what lab items
Petri dishes, pipettes
140
Ethylene oxide limitations
* toxic (must be extensively aired), explosive,
mutagenic and potentially carcinogenic
* Must be eliminated by heated forced air for 8 to 12 hours
141
oxidize proteins, cellular components
halogen
142
Destroys all microorganisms and viruses
* Used as disinfectant
type of halogen: chlorine
143
what dilution of chlorine is most effective
* 1:100 dilution
144
Very low levels disinfect drinking water
chlorine
145
Can react with organic compounds in water
chlorine
146
Kills vegetative cells, unreliable on endospores
type of halogen: iodine
147
Used as tincture
type of halogen: iodine
148
antimicrobial chemical dissolved in alcohol in
alcohol
tincture
149
High concentrations too toxic to be used medically
Metal Compounds
150
still used as an antiseptic: creams, bandages
silver
151
once widely used as preservatives
Compounds of mercury, tin, copper
152
Unstable form of oxygen
Ozone (O3)
153
Decomposes quickly and Powerful oxidizing agent
Ozone (O3)
154
Ozone (O3) is an alternative for what
chlorine
155
powerful oxidizers used as sterilants
Peroxygens
156
are Peroxygens biodegradable
yes
Readily biodegradable, no residue
157
are Peroxygens toxic
Less toxic than ethylene oxid
158
Hydrogen peroxide is most effective on what
More effective on inanimate object (vs. tissues)
159
does Hydrogen peroxide damage materials
Doesn’t damage most materials, no residue
160
more potent than H2O2
Peracetic acid
161
Effective on organic material
Peracetic acid:
162
Sterilizes in less than 1 hour; useful on wide range of material
Peracetic acid
163
one of earliest disinfectants
Phenol (carbolic acid)
164
Has unpleasant odor and irritates skin
Phenol (carbolic acid)
165
kill most vegetative bacteria but not all viruse
Phenolics
166
benefits of Phenolics
Wide activity range, reasonable cost, non-toxic for skin applications, remain effective in presence of detergents and organic contaminants
167
type of Quaternary Ammonium Compounds
Cationic (+ charged) detergents
168
Positive charges of quats attracted to negative charges of cell surface
Cationic (+ charged) detergents
169
benefits of Cationic (+ charged) detergents
Low toxicity, disinfection of food preparation surfaces
170
what resists Cationic (+ charged) detergents
Pseudomonas
171
where are Cationic (+ charged) detergents found
personal care products
172
Food preservatives must be non-toxic for safe ingestion
Chemical preservatives
173
* Affect cell membrane function
* Control molds and bacteria in foods
Weak organic acids (benzoic, sorbic, propionic)
174
used in processed meats
Nitrate and nitrite
175
Inhibit endospore germination and vegetative cell growth
Nitrate and nitrite
176
are Nitrate and nitrite carcinogenic
yes when converted to nitrosamines by
cooking or intestinal bacteria
177
inhibits growth of pathogens and spoilage organisms by slowing or stopping enzyme reactions
Refrigeration
178
preserves by stopping all microbial growth
Freezing
179
killed by ice crystal formation, but many survive and can grow once thawed
microbial cells
180
water exits bacterial cells
plasmolysis
181
bacteria that grow in high salt environments
Staphylococcus aureus
182
freeze drying foods
Lyophilization
183
stops microbial growth but does not reliably kill
Drying
