mycobacterium Flashcards
(190 cards)
1
Q
general characteristics
A
aerobic, non spore forming basilli, slow growing (20 hours)
2
Q
mycobacterium will not grow from
A
specimen to culture plate (specialized media)
3
Q
referred to as
A
acid fast
4
Q
acid fast
A
resist decolorization with acid ethanol due to high level mycolic acid in cell wall
5
Q
mycolic acid doesn’t allow
A
gram stain
6
Q
mycobacterium resistant (can’t grow) to
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antimicrobals
7
Q
world’s leading cause of morbidity
A
mycobacterium
8
Q
level 1
A
no testing; specimen collection and sent out
9
Q
level 2
A
microscopy testing; culture ID and MAYBE susceptibility
10
Q
level 3
A
everything; microscopy, ID, susceptibility
11
Q
TB commonly acquired through
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lab worker infection
12
Q
spread through
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aerosolization
13
Q
students are now not allowed
A
to set up mycobacterium testing
14
Q
things needed when testing
A
gowned, gloved, fitted for N95 mask, checked off check list that you are properly trained, once a year get tested
15
Q
mycobacterium must be tested under what hood
A
biosafety 2
16
Q
disinfect mycobacterium by
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sodium hypochlorite (10% bleach)
17
Q
under hood turn on
A
UV light to decontaminate
18
Q
centrifuge requires
A
special covers (domed) and specimen should be closed
19
Q
classification
A
runyon classification
20
Q
photochromogen
A
pigment when exposed to light (yellow/ orange)
21
Q
scotochromogen
A
pigment in the light and dark
22
Q
pigment grows in
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5 days
23
Q
strict pathogens
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not matter where isolated always pathogenic
24
Q
non chormagen
A
doesn’t fit into any category
25
MOTT
mycobacterium other than tuberculosis complex
26
collection rules of thumb for mycobacterium
1) always set up fresh specimen
2) can't set up immediately-- need fridge-- slows growth of norm flora
3) respiratory specimen collect AFB x 3 (1st morning specimen for 3 consecutive days)
4) respiratory sputum -bloody sputum
5) never accept 24 hr specimen
27
what specimen used for mycobacterium
sputum
bronchoalveolar lavage or washing
urine (FMS x 3)
gastric aspirate
blood
stool
tissue/body fluids
28
when should you only use gastric aspirate
only on younger children who can't produce sputum (gastric juices can kill organism)
29
when is a stool culture acceptable
MAI
30
how to store tissue/body fluids
incubated at RT for 37
31
if the specimen has mucolic acid
needs special processing
32
what to proceed with after deciding need special processing
1) digest/decontamination
2) homogenous
3) concentration
33
1) digest/decontamination
-digest normal flora
-combine 4% NaOH with 2.9% sodium citrate
mix equal parts of specimen and digest-- add in NALC
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what is NALC
anti-mycolic agent
-break down mucous strands and release mycobacterium
35
2) Homogenous
-vortex until liquid
-add more NALC if not liquid enough
-sit 15 min-- kill of normal flora
-after stop digest procedure or will kill off
36
3) concentration
-add phosphate buffer-- stops digest and help dilute toxic substances and decrease specific gravity so centrifuge better
-centrifuge for 15-30 min
take most concentrated part and use in inoculating media and for staining
37
after concentration if urine
keep bottom part (take off top)
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after concentration if respiratory
dump liquid and keep pellet
39
why add oxalic acid
kill of pseudomonas bc they can overcome digest and liquify the media
40
other to get rid of mycolic acid
zephiran tech
41
zephiran tech
-not as time specific (sit longer and won't kill off)
-uses trisodium phosphate benzalkonium chloride
Disadvantage: won't kill off as much normal flora
42
slides must be done on EVERY mycobacterium bc
1st indicator person has the infection (takes long time to grow)
43
another reason to make a slide
only way to determine if (doesn't always grow on media)
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3rd reason to make a slide
decrease in # of organisms on slide shows therapy is working
45
how many fields must be read to call mycobacterium -
100 fields
46
auramine rhodamine
-fluorscent
-most sensitive
Primary stain: auramine rhodamine leave on for 15-20 min
then add decolorizer-- 2-3 min
then add potassium peragimate =counter stain
47
what is the purpose of potassium pergermate
quenching agent: helps neutralize background fluorescence and see organism clearly
48
mycobacterium on auramine rhoadamine
bacilli rods
orange or green (depends on wavelength)
49
disadvantage of fluorscent
need fluorescent microscope
50
if you find something on a fluorescent stain must
also do a non fluorescent
51
kinyoun stain
-most common
-non fluorescent
-cold tech
no heat because terdoiul
main stain: carbonyl fusion -- leave on 10-15 min
acid decolorizer
counterstain: methylene blue
52
how does mycobacterium appear on kinyoun stain
acid fast bacilli against blue background
PINK
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Ziehl-Neelson
hot tech
-non fluorescent
carbonyl fusion but no terigoul
decolorize and add methylene blue
let sit/dry for 2 hours before reading
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after making a slide
plate onto media
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lowenstein jensen
-egg based
-most common
-malachite green= selective agent
-slants
-incoulate and lay on side so material spreads
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petragnani media
-egg based
-contains 3x malachite green
-very selective; only use for heavy growth
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american thoracic society medium
-egg based
-half malachite green as LJ
-will have lots of junk left over
58
middle brook agar
-agar based
-low amount of malachite green
Good for: susceptibility and growing organism susceptible to malachite green
59
ALWAYS use what kinds of media
egg based AND agar based
60
how to incubate mycobacterium
capnophilic-- CO2 5-10%
horizontally for 1-2 weeks for good surface area
35-37 degrees celsius
61
how to incubate skin/ wound culture
RT
62
how often do mycobacterium incubate get read
once a week
63
how long to keep media
8 weeks before calling negative
64
if suspected photo or scto
set up slants under desk lamp --- allows for heat and pigmentation
65
mycobacterium tuberculosis
NOT normal flora-- strict pathogen
66
where is mycobacterium tuberculosis prevalent
3rd world countries
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how is mycobacterium tuberculosis transmitted?
human to human by aerosolization
68
what percent of people who inhale mycobacterium tuberculosis get it?
5% symptomatic
69
what is the main place in the body mycobacterium tuberculosis infects and why?
the lungs because high levels of O2 BUT can infect anywhere
70
primary TB
person develops symptoms after exposure to organism --- could be months or years after exposure
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symptoms of primary TB
blood tinged sputum!!
night sweats
fever
anorexia
weight loss
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what happens in the body during primary TB infection
trys to fight the infection with macrophages but organism can live and multiply in macrophages
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immunity for primary TB
Tcell-- fights intracellular antigen: produces cytokines to kill off
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as macrophage breaks down
organism is still alive and more macrophages are called : tuberculosis ends up in lungs and tissue is necrosis and calcified
75
what is calcified tissues in the lungs called?
Ghon Complex
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after someone heals from primary TB- some is still left over and leads to
secondary TB
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secondary TB can be worse than primary because
suppressed immune system because older
78
secondary TB can lead to
miliary TB and moves from lungs to other parts of the lungs
79
miliary TB can get into spinal fluid and lead to
Pott's disease
80
what is pott's disease
spinal fluid with TB -- spider like fibrin strands (webb particle)
81
PPD Test
delayed hypersensitivity text
don't read until 48 hours after
thin needle and under skin inject PPD
go back after 48 hrs
if harden red nodular 1-3 mm = +
no bump= -
82
what hypersensitivity involves PPD
T cell hypersensitivity
83
PPD stands for
purified protein derivative
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NEVER DO PPD on anyone with vaccination bc
major T cell response
85
TB vaccine will give a
false positive
86
when + PPD you can't tell the difference between if
active TB, past infection
87
why is PPD not liked
false positives, need trained personal, can't see what kind of infection (past, present, allergic)
88
if 1st PPD was negative do
2nd injection PPD
89
why do 2nd injection PPD
latent TB is waken and shown with a + response
90
if PPD is +
follow up with chest X-ray and culturing
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what can cause + PPD
active infection
vaccine
prior exposure to TB
latent TB
92
why a false - for PPD
immunocompromised system
93
what testing do we do now for TB
Gamma Interferon testing
94
how does gamma interferon testing work
blood incubated with mixture of synthetic peptides stimulates proteins found in MTB
95
what is in the synthetic proteins
culture filtrate protein 10 and
early secretory antigenic target
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measure baseline gamma interferon and after blood mixed with 2 antigens look for
increase
97
calculation for gamma interferon
interferon after stimulation - baseline of interferon
difference determines + or -
98
pre-analytical for gamma interferon
need to reach lab 16-17 hours or else not valid
99
gamma interferon can not be done on kids
under age 17
100
gamma interferon is NOT
affected by vaccine
101
what are 2 kinds of new TB testing?
gamma interferon and t-spot
102
how temp does MTB grow
35-37
103
what does MTB colonies look like
non pigmented, tanish and kinda dry, eugonic looking (easily picked off media but hard to break off into liquid)
104
tests for MTB
nacyin +
nitrate +
catalase +
105
PCR is used for
enhancement
106
growth of TB liquid media
can inculate (middlebrook) and put on blood culture system
107
advantage of liquid
organism grows faster in liquid and monitored 24/7
108
if blood culture +
do smear, auramine and kinyon stain
-call doctor
-lowerstein jensin and middle brook plate
109
if blood culture -
put back on machine
110
MTB is inhibited by ______ but other myco. bacterium is not
NAD
111
liquid bottle and smear + =
know mycobacterium
112
what to do when first +
draw liquid out of blood culture and into another culture bottle and add NAP
113
after putting into new culture bottle
put back on machine for 3-5 days
-if increase 2-3 fold =MTB
-if increase 10 fold or more= not MTB
114
treatment for TB
6-18 months
seen a lot in underdeveloped countries bc people don't have access to treatment and don't take all meds
115
primary Tb drug
isoniazid and rifampicin
116
drugs for MTB involves
cocktail of primary and seconday drugs
117
you need a cocktail of drugs to treat Tb because
organisms mutate to become resistant
118
what % of newly diagnosed MTB is resistant to 1 of the primary drugs
80%
119
in the U.S only ____ resistent
1-2%
120
mutli-drug resisten Tb
resistent to both primary drugs
121
XDR-TB
extremely resistant to TB
-resistant to 2 primary drugs and at least 1 secondary drugs
122
how do you treat XDR-TB or MDR TB
6-20 drugs per day for 6 months
123
mycobacterium BOVIS
found in cattle
passed to man from unpasteurized milk and goat's unpasteurized milk
124
mycobacterium BOVIS spreads to
respiratory tract (mild form of TB) no latent infections or death rate
125
how is mycobacterium BOVIS important
vaccine is made from this
126
BCG stands for
bacille calmette- guerin
127
BCG is used as treatment for
bladder cancer
128
how to ID mycobacterium BOVIS
nonpigmented and buff color
-up to 40 days to grow
NICIN -
NITRATE -
129
mycobacterium BOVIS does NOT grow in the presence of
T2H-- thioplene-2-carboxylic acid hydrazide
130
mycobacterium leprosy called
handis bacilli
131
why is mycobacterium leprosy unique compared to other myco
1) never been grown in vitro
2) slowest growing of all myco on human
132
how long is mycobacterium leprosy incubation time
20 years
133
what does mycobacterium leprosy affect
skin and nerves
134
mycobacterium leprosy pathogenicity
not sure of reservoirs
in US- Armadillos in respiratory system
135
mycobacterium leprosy is not extremely contagious person to person need
close contact for years
136
2 forms of mycobacterium leprosy
tuberculoid and lepromatous
137
tuberculoid leprosy
most superficial (hypo and hyper pigmentation of the skin)
-lose sensation of pain bc nerves
-not life threatening - remains at skin (cell mediated)
138
is tuberculoid life threatening ?
no
139
how do you diagnose tuberculoid?
feather test- can you feel sensations
140
Lepermatis
-more life threatening
-do no mount cell mediated response
-allows to attack other organs
-slow progressing
-scarring of hands and feet
141
what drugs treat tuberculoid and lepermatis?
dapsone and rifampin
142
M. Kansasii
3rd most common respiratory
not as life threatening as TB
143
how is M. Kansasii isolated
sputum
144
M. Kansasii transmitted
not easily transmitted man to man
seen in immunocompromised (men more)
145
M. Kansasii growth
photochromogen
in light: form beta keratin crystals
take 2-3 weeks to grow
146
M. Kansasii claim to fame
tween 80 hydrolysis +
nicin -
nitrate +
147
M.Marinum (marine)
-found in contaminated water -- fish tank, pools
pathogen on skin- NEVER isolated from sputum
cause-- swimming pool granuloma
148
how to contract M.Marinum
open wound and isolated hands and feet (colder parts)
149
how to incubate M.Marinum
incubate 30 degrees
can be missed in incubator
150
what to suspect if all other cultures negative
M.Marinum (marine)
151
how to treat M.Marinum (marine)
amino glycocids
152
M. xenopi
international travel make it more common
associated: slow growing pulmonary infection
-seen in pre existing
153
what temp do M. xenopi grow
42 and 37
154
what does M. xenopi look like on middlebrook
bird/ egg nest colony
155
scotochromogens pigment
yellow/orange
156
M. Scrofulaceum
infection: cervical lymphadenitis in children
attacks: jawline and gets into bone
treatment: surgical removal
157
M. gordonae
tap water bacillus -- sinks, showers, and bath tubs
158
what us most common scoto in labs
M. gordonae
159
what to suspect is multiple patients in certain timeline growing gordonae
media contamination from company who is making them with water used
160
m. szulgai claim to fame
cutaneous and pulmonary infections
161
what temp does m. szulgai grow
37 and 42
162
m. szulgai drugs
susceptible to all drugs
163
MAI
mycobacterium avium intracellulare
164
Slow MAI
slow progressive pulomary disease with lung disfunction
165
Disseminating MAI
HIV, AIDS, T-cell deficiency
isolate: this is only micro recovered from stool
but also recovered from sputum, bone, lung absess
166
MAI pigment
non pigmented
167
MAI resistance
resistant to all drugs so needs a cocktail to be treated
168
rapid growers
5 days
169
used to be considered a complex but now together
fortuitum and cheloni
170
rapid growers cause what kinds of symptoms
respiratory and cutaneous
171
when everything else is ruled out its
cutaneous
172
incubated at lower temps=
no digest
173
when you make a gram stain from sample and no bacteria is seen
no digest procedure
174
if you makes a gram stain and bacteria is seen
do digest procedure
175
detect presence of rapid growers
arylsulfatase test = 3 days +
176
______ doesn't replace culture
PCR
177
niacin testing is for
TB
178
what happens in niacin testing
enzyme will convert free mycin to mycin ribonucleotide
TB DOES NOT HAVE THIS ENZYME
free niacin will accumulate in media and detect nicotinic acid
do on lowenstein jensen slant-- need at least 50 colonies
stab media= release free niacin and place some sterile water in slant--
lay horizontal for 30 min
turn upright and add reagent slip== yellow +
179
nitrate to nitrite procedure
once colonies grown on slant put into nitrate broth
add sulfanilamide and napthyylenediamine
LOOK for pink +
if no color= no conversion or used all nitrogen gas
add zinc dust = if pink
+ still have some nitrates
180
what organisms are nitrate +
TB and Kansasii
181
Tween 80
oleic acid broken down to polyoxyethalylated sorbitol
when olecic broken down-- release chromagen = red
182
what organism tween 80 +
kansasii
183
catalase test done in a
tube
184
what us reagent for catalase test
1% hydrogen peroxide
185
non heat catalase test
will be + if bubbles over 45 mark
186
heat test catalase
heat at 68 degrees for 20 min and completely cool down
add reagent and see if goes over 45 mark
187
if heat +
resistent to anti-myco drugs
188
arylsulfatase break down
phenolphthalein disulfide to phenolphthalein
+ if red/pink in 3 days
189
what organism is arylsulfatase +
fortuitum
190
what organism is arylsulfatase -
MAI-- avium
