Exam 2 Flashcards
(172 cards)
1
Q
microorganisms are ubiquitous meaning
A
there is a species of microorganism that is able to adapt and occupy almost every environment
2
Q
microbes are used in the food industry to produce
A
wine, cheese, sauerkraut
3
Q
opportunistic pathogen
A
often harmless but can cause disease if conitions are right
4
Q
nosocomial infection
A
infection that an individual acquired while in a health care facility
5
Q
physical control method examples
A
heat, drying, filtration, irradiation
6
Q
chemical control methods involve the use of
A
chemical to interfere with an organisms ability to survive or multiply
7
Q
chemical control method example
A
disinfectants, antiseptics, antimicrobial therapy
8
Q
antimicrobial agent refers to
A
either a chemical that halts the growth of an organism or one that causes death of an organism
9
Q
chemicals that interfere with microbial growth usually have some effect on other life forms. One must weigh the benefit of ________ ____ with the degree of _________ ____ __________
A
microbial death, human cell damage
10
Q
-cidal
A
when the agent kills the organism
11
Q
-static
A
agents that halt the growth of a particular class
12
Q
antimicrobial agents
A
chemicals which will or prevent replication of a microorganism. This term is often used in reference to pharmacutial agents as opposed to cleaning agents
13
Q
antiseptic
A
chemical that reduces the number of microbes on animate objects, typically reduces the number of microbes significantly
14
Q
cleaner
A
agent used to remove dirt, oil, dead cells and other debris from an object
15
Q
disinfectant
A
chemical that reduces the number of microbes on an inanimate object, often significantly reduce the number of microbes present
16
Q
inhibit growth
A
render an organism unable to multiply but not necessarily kill each cell present
17
Q
kill
A
render an organism unable to metabolize or multiply again
18
Q
physical control methods
A
procedures which reduce the number of microbes present to a safe level by exposing microbes to physical conditions outside of their growth tolerance levels
19
Q
sanitize
A
used in food prep industry to refer to the action of reducing the number of microbes specifically on eating utensils and food preparation surfaces
20
Q
sterilize
A
process of completely eradicating microorganisms from an object or substance
21
Q
heat kills bacterial cells by
A
damaging or denaturing the essential proteins in the cell
22
Q
moist heat destroys bacteria by
A
altering the 3D structure of microbial proteins causing coagulation
23
Q
dry heat
A
oxidizes proteins and other components
24
Q
shorter or longer or normal times must be used when attempting effective kill with large volumes or greatly soiled items
A
longer
25
incineration
burning an item
26
the higher the temp
the more quickly proteins are denatured and the more quickly the cells are killed
27
the longer the time of exposure to the heat
the higher the number of cells killed
28
TDT
thermal death time
29
TDP
thermal death point
30
TDT is when __________ is constant but _____ is the variable
temp, time
31
TDP is when _____ is constant but ________ is the variable
time, temp
32
TDT definition
shortest time needed to kill all cells in a specific organism culture at a specific temp
33
what are some structural elements a cell can have to resist heat
capsules, endospores, enzymes
34
autoclave will destroy what relating to endospores
vegetative cells and formed endospores
35
pressure the autoclave exerts
15lbs/in2
36
temp autoclave reaches
250F/121C
37
in an autoclave at correct conditions how long will it take to kill an endospore
12-15 mins
38
why do large volumes of liquid and dense materials require longer time in the autoclave
need to allow time for steam under pressure to penetrate all areas of material in autoclave
39
what are the most difficult organisms to kill by heat
thermophilic bacteria
40
what is the most commonly used quality control method to check if the autoclave is functioning correctly
QC vials containing endospores (bacilli's stearothermophilus)
41
what color will the autoclave tape become once it has reached the specific temp
black and white stripe
42
autoclave tape will tell us that either the surface or the internal reached a specific temp
surface
43
some organisms are firmly attached and difficult to remove with handwashing
resident flora
44
organisms picked up through contact with objects in the environment
transients
45
is transient or residential easily spread
transient
46
where are residentials found
within the skin layer
47
man made sources of UV radiation include
tanning booths, sterilization units, UV wands, light boxes
48
3 types of UV radiation
A, B, C
49
UV radiation causes __________ ______ to form in DNA
thymine dimers
50
can UV light penetrate sufraces
no
51
UVA wave length
315-400nm
52
UVB wave length
280-315nm
53
UVC wave length
200-280nm
54
UVA ability to penetrate skin
deepest to middle dermal layer
55
UVB ability to penetrate skin
to outer dermal layer only
56
UVC ability to penetrate skin
does not penetrate, affects only surface cells
57
UVA ability to penetrate the ozone layer
yes
58
UBV ability to penetrate the ozone layer
yes
59
UVC ability to penetrate the ozone layer
little to none
60
UVA health risk
sunburn, premature aging, skin cancer
61
UVB health risk
sunburn, premature aging, skin cancer
62
UVC health risk
severe burn, temporary inability to see, very little cancer risk
63
UVA found in
sunlight, tanning booths, some lighting sources
64
UVB found in
sunlight, tanning booths, some lighting sources
65
UVC found in
sunlight prior to filtering through ozone, man made lamps, light boxes
66
UVA bactericidal
very little
67
UVB bactericidal
limited
68
UVC bactericidal
antibacterial: air or surface sterilization only
69
sterilization by filtration is based on the inability of microorganisms to pass through
a filter with pores
70
filtrate
liquid after passing through the filter
71
filtration by size is only one type of filtration what is another one
chemical filtration which causes chemical changes to the liquid passing through
72
example of chemical filtration
lead removal
73
choice of a disinfectant is based on
target microbe, material to be disinfected, and conditions in the surrounding environment
74
chemicals that are used to destroy microbes on inanimate surfaces are referred to as
disinfectants
75
example in the lab of a disinfectant
solution applied to bench top before and after lab
76
chemicals applied to animate surfaces to reduce the amount of bacteria present are called
antiseptics
77
example of antiseptics
isopropyl alcohol
78
do disinfectants sterilize
no
79
typically disinfectants target _________ for destruction and the disinfecting chemical may not destroy all organisms that are present
pathogens
80
differences in microbial structure result in different
susceptibilities to the active ingredient in disinfectant solution
81
what bacterial structure is resistant to chemicals
endospores
82
solutions of disinfectant should be freshly prepared because the chemical may be
less effective over time
83
The use dilatation method compares the ability of various disinfectants at the ___________ recommend for use to kill a specific microorganism
dilution
84
procedure for the use dilatation method
test organism is dried on a solid surface and exposed to the disinfectant at use dilatation for specific time periods
85
the Kirby Bauer test us used to test several
antimicrobial agents for the ability to inhibit the growth of a strain of pathogenic organism
86
all of these steps in the Kirby Bauer test must be followed to the letter
- strain must be well isolated and grown in a broth to a specific concentration
- the broth culture is spread evenly over the surface of a Mueller-Hinton agar plate of specified thickness
- filter paper discs, each with a specific concentration of a different drug, are placed on the agar plate
- the plate is incubated for 18-24 hours at 37 degrees C and examined
- the diameter of the zone of inhibition around each disc is measured in millimeters
- interpretation table is consulted to determine the susceptibility of the test microbe to the antibiotic
87
antimicrobial agents with an inhibitory effect on the organism will cause a ________ ____ ____________ to appear around the disc (no growth around the disc)
zone of inhibition
88
interpretation chart was developed as a result of studies that correlated zone size obtained in the lab setting with the
recovery rate of patients treated with that drug
89
when a person has a bacterial infection before treatment is begun
a clinical specimen should be obtained from the site of infection
90
direct smear
stain preformed on a portion of the original specimen and will contain stained cells and debris from the collection site
91
initial culture results called __________ ____ give general information such as gram stain and shape found. These can be obtained 24 hours after specimen collection
preliminary report
92
2 important genera of gram pos cocci that contain pathogens
streptococci, staphylococci
93
pyogenic
infections that cause many WBC to travel to the site of infection creating a purulent exudate (pus)
94
gram reaction results for Staph species
gram pos
cocci
clusters
95
catalase results for Staph species
positive
96
tolerance for 7.5% salt results for Staph species
positive
97
hemolysis on blood agar results for Staph species
beta/nonhemo
98
colony morphology results for Staph species
white, cream, opaque
99
gram reaction results for Strep species
gram pos
cocci
chain
100
catalase results for Strep species
negative
101
tolerance for 7.5% salt results for Strep species
negative (only positive species is enterococcus)
102
hemolysis on blood agar results for Strep species
alpha/beta/non
103
morphology on blood agar results for Strep species
usually gray, translucent
104
what is the differentiate step between staph and strep species and what is the result for each species
catalase test
stap species= positive
strep species= negative
105
what is the order of differentiation after we get a positive catalase test
coagulase
7.5% salt tolerant/manitol fermentation
106
what is the order of differentiation after we get a negative catalase test
bile esculin
hemolysis
A and P disc
107
under what hemolysis conditions will we use the P disc
alpha hemolysis
108
under what hemolysis conditions will we use the A disc
beta hemolysis
109
growth on manitol salt agar means the organism is
tolerant to 7.5% salt agar
110
the catalase test shows if there is a presence to the enzyme __________ which allows organisms to break down ______
catalase, h2o2
111
you perform a salt tolerance on manitol salt agar and notice there is no growth, this test is negative or positive
negative
112
you preform a catalase test and notice there is bubbles appering, this test is negative or positive
positive
113
what are 2 common things found in the lab that will react with H2O2 and we need to follow proper protocol to get a correct catalase test
metal loop and agar of blood agar
114
since metal reacts with H2O2 we want to use a
steril cotton swab
115
coagulase tests for the enzyme _______ which causes a ____ formation
coagulase, clot
116
you preform a coagulase test and you notice a clot formed, this test is positive or neagtive
positive
117
what staph species is of major concern
staphylococcus aures
118
hemolysis tests for
the ability of organisms to hemolzye blood cells
119
beta hemolysis will present
with transperency on the agar
120
alpha hemolysis will present
green like, non transparent
121
gama hemolysis will present
with no change
122
you preform a hemolysis test and you first look at the plate and it appears green but once you hold it up to the light you notice it is transparent, what type of hemolysis is this
beta
123
bile esculin will only test positive for
enterococci species
124
you preform a bile esculin test and there is obvious black color change, this is
positive
125
what species is sensitive to the A disc
streptococcus pyogenes
126
P disc is the common test for what species
streptococcus pneumonae
127
example of group A streptococci
S. pyogenes
128
Group A produce what hemolysis
beta
129
example of group D streptococci
streptococcus faecalis
130
group D can be identified through what test
bile esuclin
131
streptococcus pneumonia present how
gram pos diplococci
lancet shape being more poised on one side
132
strep throat is commonly caused by what species
strep pyogenes
133
UTI refers to an infection in the
kidney, ureter, bladder, urethra
134
upper UTI involves the
kidney
135
lower UTI involves the
bladder and urethra
136
nephritis
infection of kidney
137
nephritis can not always be caused by UTI, it can also be caused by
toxins in the blood, like sepsis
138
cystitis
infection to bladder
139
cystitis is often caused by
organisms originating in the external genetailia
140
what is the most common pathogen for UTI
e. coli
141
who gets more UTIs, male or female
female
142
what is the most common collection of urine
voided sample
143
voided sample
first pee of the day
144
contamination during sample collection is assumed the probable source of organism see if
- small number are present
- large variety of organisms are present in any amount
145
infection is assumed present if
- large amount of organisms are present, almost entirely from the same species
146
E. coli can double every __ mins
20
147
urine is both __________ in content and at optimal _________ for growth
nutritive, temp
148
if urine is not transported and stored properly this could cause
falsely high report
149
how should a urine sample be stored/transported
refrigerated
150
lawn flora
spreding organisms over the whole agar
151
10uL samples are used when
low numbers are expected (turbidity is clear or hazy)
152
1uL samples are used when
high numbers are expected (turbidity is cloudy or turbid)
153
genes transferred from one bacterium to another without replication
horizontal gene transfer
154
horizontal gene transfer quickens the spread of ______ through a population of bacteria and plays a factor in increasing the ability to ______ the effects of antimicrobic drugs
genes, resist
155
transformation
DNA fragments are free floating in the environment can be taken into a cell
156
competent cell
cell that allows DNA fragments to enter
157
competent cell is often due to larger
pores
158
plasmids
circular bits of double stranded DNA
159
most notable competent species
streptococcus pneumoniae
160
one species that can be made competent in the lab is
e. coli
161
creating competent cells involves altering the
cellular membrane/walls
162
making a cell competent is achieved through (in this lab) exposure to chemicals like _____ and followed by _____ _____
CaCl2, heat shock
163
in lab the e.coli cells are exposed to a solution with plasmid in it called
pGLO
164
three genes of significance of pGLO
GFP, araC, bla
165
GFP stands for
Green flourensce protein
166
GFP allows the bacteria to glow green Florence under
UV light
167
araC encodes for
regulatory protein which binds to the promoter for the GFP protein, which switches this promotor on
168
bla encodes for what enzyme
beta lactamase
169
beta lactamse will cleave the ____ _______ ring in penicillin and related molecules and rendering the drug useless
beta lactam
170
once our E. coli is transformed growth on the ____ plate demonstrates the ability of the organism to survive in the presence of amplicllin
LB amp
171
growth of the pGLO- strain on the LB but not on LB amp indicated the E. coli was
susceptible to ampicillin prior to transformation
172
growth on both LB and LB amp of the pGLO+ strain indicated the organism is now able to
withstand presence of ampicillin due to the presence of pGLO
