KG - Microbiology Exam 2 Flashcards
(184 cards)
1
Q
viruses that cause ARD (common cold)?
A
adenovirus (30-40%)
rhinovirus (25%) - some say 50%?
coronavirus (10%)
2
Q
viruses that cause ARD (common cold)?
A
adenovirus (30-40%)
rhinovirus (25%) - some say 50%?
coronavirus (10%)
3
Q
diagnosis ARD?
A
clinical
4
Q
treatment ARD?
A
symptomatic only
NO Zicam
5
Q
treatment rhinovirus specifically?
A
zinc gluconate (symptomatic) Picovir - not mass market yet
6
Q
viruses that cause flu?
A
influenza A, B, C
7
Q
prevention influenza?
A
vaccines - 2 type As, 1 type B
now 2 As, 2Bs - recent change?
8
Q
diagnosis influenza?
A
rapid viral ID tests for antigen swabs
– can have false negatives early on
9
Q
treatment influenza?
A
amantadine & ramantadine = type A (stops uncoating & penetration)
oseltamivir & zanamivir = type A & B (stops spread, release)
10
Q
complications influenza?
A
pneumonia, Reyes, Guillain-Barre
11
Q
antigenic drift? (flu)
A
point mutations, H or N
12
Q
antigenic shift? (flu)
A
genome sequence recombinations - most important to pandemics
13
Q
viruses that cause Chlamydiae?
A
C. trachomatis, C. pneumoniae
14
Q
risk factor for C. trachomatis? prophlaxis?
A
infected mother, prophylaxis = silver nitrate eye drops
15
Q
common infectious state/pop of C. trachomatis?
A
infants 3 wks post birth
16
Q
C. pneumoniae also causes ___
A
bronchitis, pneumonia, sinusitis, & associated w/ atherosclerosis
17
Q
viruses that cause Chlamydiae?
A
C. trachomatis, C. pneumoniae
18
Q
risk factor for C. trachomatis? prophlaxis?
A
infected mother, prophylaxis = silver nitrate eye drops
19
Q
common infectious state/pop of C. trachomatis?
A
infants 3 wks post birth
20
Q
what syndrome is associated w/ C. trachomatis?
A
Reiter’s Syndrome
21
Q
two forms chylamidiae?
A
elementary body = infectious agent
reticulate body = growing form
22
Q
cause Croup?
A
PIV1 > PIV 2»_space;> RSV
23
Q
age typically of croup?
A
6-18 months old
24
Q
diagnosis croup?
A
direct FAB test
- must have direct viral isolation from throat/nasal swabs
25
treatment croup?
symptomatic
26
describe P. aeruginosa
G- bacilli
encapsulated
pigment producer - pyocyanin, pyoverdin (these = VF)
27
signal sign on CXR croup?
steeple sign
28
PIV causes ____
croup, OM, parotitis
29
describe PIVs
paramyxovirus, nonsegmented neg sense ssRNA, enveloped, 4 serotypes
- virion enveloped by protein spikes
- hemagglutinin & neuraminidase activities on same peplumed molecule
- NF proteins cause syncytia formation
30
most vulnerable to PIV?
immunocompromised
31
diagnosis PIV?
direct FAB test
| - must have direct viral isolation from throat/nasal swabs
32
lifelong immunity to PIV?
NO, but usu mild later on
33
treatment PIV?
symptomatic
34
vaccine PIV?
NONE available
35
group common of winter outbreaks RSV?
infants < 1 yo (peak 2-3 months old)
36
most common cause LRIs?
RSV
37
why symptoms in RSV?
infection of epithelium of resp tract --> causes inflammatory response of IgE and Tcells
38
risks for RSV?
birth 3-4 months prior to winter, kids w/ underlying dz, premature birth, cardiac/resp abnormalities
- also immunocompromised adults
39
diagnosis RSV?
rapid antigen test & immunofluorescence assay
| serology not common anymore
40
treatment RSV?
monoclonal immune globulin for high risk pts (Palivizumab)
Ribavirin (controversial)
41
cause Otitis Externa?
P. aeruginosa & S. aureus
42
describe S. aureus
G+ cocci
encapsulated
COAG +
beta-hemolytic (+ if you can see through plate)
43
diagnosis OE?
exam, gram stain
44
treatment OE?
remove debris, topical antibiotics, oral antibiotics if fever, systemic analgesics
45
describe VOLUTIN staining for diphtheria?
Volutin = metachromic (volutin) granules
46
describe S. pneumoniae
G+ diplococci lancet
encapsulated
alpha-hemolytic (can't see through plate)
optochin sensitive
47
describe H. influenzae
G- coccobacilli
| non-typeable strain
48
describe M. catarrhalis
G- diplococci
oxidase positive
beta lactamase producer
49
diagnosis AOM?
clinical, tympanocentesis to aspirate fluid in severe pts, culture/stain
50
diagnosis sinusitis?
clinical/hx, nasal cytology, CT, allergy testing
51
treatment AOM?
amoxicillin, tubes for chronic
52
treatment sinusitis?
varies depending on cause - irrigation, analgesics, OTC decongestants, antibiotics, steroids, surgery
53
cause diphtheria?
Cornebacterium diphtheriae
54
describe cornebacterium diphtheriae
G+ pleomorphic bacilli
metachromic gracules
aerobic on blood agar
"Chinese letter appearance"
55
signs diphtheria (cutaneous)?
non healing ulcers
56
signs diphtheria (respiratory)?
sudden onset, malaise, fever, lymphadenitis, BULLNECK, PSEUDOMEMBRANE
57
diagnosis diphtheria?
clinical, culture & staining
58
describe culture: Loeffler's medium?
for diphtheria:
| supports growth and enhances formation of volutin granules
59
major complication pertussis?
pneumonia
| - also vomiting, increased intracranial pressure, seizures, encephalopathy
60
describe GRAM staining for diphtheria?
Gram = club shaped, G+ bacilli
61
describe VOLUTIN staining for diphtheria?
Volutin = metachromic (volutin) granules
62
treatment diphtheria?
antitoxin, erythromycin, isolation, & vaccination once pt recovers
63
VF diphtheria?
AB exotoxin -- B binds to receptors, is endocytosed, vesicle acidifies, A subunit released, A subunit inactivates EF-2 ADP ribosylation & halts protein synthesis
64
cause Pertussis?
Bordetella pertussis
65
describe bordatella pertussis
G- coccobacilli
aerobic
VF: 2 adhesins, 4 exotoxins
66
what do adhesions do in pertussis?
mediate attachment to integrins & colonization of ciliated respiratory epithelium
67
pertussis exotoxins (4)
1. pertussis toxin (AB exotoxin) = lymphocytosis
2. adenylate cyclase toxin = causes decreased chemotaxis
3. dermonecrotic toxin = vasoconstriction, necrosis
4. tracheal cytotoxin = kills ciliated resp epithelial cells
68
describe stage 1 pertussis
catarrhal stage: inflamed mucosa, contagious, 7-10 day incubation, nonspecific URI
69
describe stage 2 pertussis
paroxysmal stage: attacks/spasms w/ "whoop" sound that can be followed by vomiting, labored inspiration, 2-4 wks
70
describe stage 3 pertussis
convalescent stage: gradual recovery wks - months
71
diagnosis pertussis?
presumptive diagnosis = ELISA serology
| definite diagnosis = culture or PCR
72
treatment pertussis?
erythromycin (or Bactrim)
73
what cultures are used for Pertussis?
Bordet-Gengon agar
| Regan-Lowe agar
74
vaccine for pertussis?
YES - prevention is key
75
major complication pertussis?
pneumonia
| - also vomiting, increased intracranial pressure, seizures, encephalopathy
76
causes CAP, typical?
S. pneumoniae
H. flu
Klebsiella pneumoniae
S. aureus
77
causes CAP, atypical, zoonotic?
C. psittaci
F. tularensis
C. bunetii
78
causes CAP, atypical, non-zoonotic?
C. pneumoniae
M. pneumoniae
L. pneumoniae
79
which is most common cause of CAP?
strep pneumoniae = 60-70% CAP
80
describe strep pneumoniae
```
G+ diplococci lancet
encapsulated
alpha-hemolytic (greenish-grey colonies)
optochin sensitive
~90 serotypes (based on capsule)
```
VF: capsule, pneumolysin, autolysin, teochoic acid
81
diagnosis CAP via strep pneumoniae?
consolidation on CXR
gram stain (G+ lancet diplococci, non staining capsule - not req for growth)
culture & sensitivity (blood agar, small, greenish colonies)
agglutination test for capsule saccharides
genetic probe
82
treatment CAP via strep pneumoniae?
PCN G
83
presumptive diagnosis CAP (strep pneumoniae)?
optochin sensitivity
84
confirmation test CAP (strep pneumoniae)?
bile solubility test - bile will lyse alpha hemolytic strep pneumoniae, but have no other effect on other alpha hemolytic strep
85
what is the Quellung reaction use for w/ CAP?
to observe capsules - mix organism isolated from pt w/ known anti-capsule serum (used when two possible capsules in sample)
86
vaccine for CAP?
YES - 23 & 13 valent
87
CAP VF strep pneum: capsule?
C3b prevents opsonization - inhibits phagocytosis
88
CAP VF strep pneum: pneumolysin?
forms transmembrane pores, results in lysis & activates complement
89
CAP VF strep pneum: peptidoglycan/techoic acid?
causes overstimulation of immune response
90
CAP VF strep pneum: autolysin?
lysis of strep cells causing release of pneumolysin - response to antibiotics, dampen host response
91
when will H. influenzae lyse RBCs?
requires comorbid infection to lyse RBCs
92
CAP VF strep pneum: H2O2?
apoptosis in host cells, eliminate competing bacteria
93
CAP VF strep pneum: pili?
contribute to colonization of URT, activate production of TNF
94
CAP VF strep pneum: surface proteins?
choline binding proteins - adhesins that interact w/ carbohydrates on surface of plum epithelial cells
95
describe Klebsiella pneumoniae (CAP & HAP)
G- bacilli
non-motile
thick, slimy coat
in normal flora
96
CAP VF M. pneumoniae?
adheres to epithelium, releases H2O2 - damage
| evades immune system by fusing to host cells w/ sterols
97
symptoms CAP/HAP klebsiella pneumoniae?
lung hemorrhage - CURRENT JELLY SPUTUM
98
diagnosis CAP/HAP klebsiella pneumoniae?
gram stain
culture = mucoid capsule
sputum culture
cavitation on CXR
99
treatment CAP/HAP klebsiella pneumoniae?
combo therapy = 3rd gen cephalosporin + aminoglycosides + fluoroquinolone
*Need susceptibility testing
100
which cause of CAP is opportunistic pathogen for pts w/ DM & alcoholics?
CAP/HAP klebsiella pneumoniae
101
treatment CAP C. pneumoniae?
DOC = erythromycin, tetracycline
102
describe Haemophilus influenzae
```
G- coccobacilli
non-motile
encapsulated or non-encapsulated
NONHEMOLYTIC but requires RBCs to grow
if loses capsule = non typeable (but still causes dz)
```
103
CAP VF H. influenzae?
LOS (similar to LPS)
capsule
polyribosylribitol phosphate (PRP) = resistant to phagocytosis by PMNs ***major factor
fibriae req for colonization of nasopharynx
- also.. produce neuraminidase & IgA protease
104
diagnosis CAP H. influenzae?
difficult to culture - culture shows SATELLITE on blood agar, usu use chocolate agar
serologic testing for type if encapsulated (best way to diagnose)
Latex Particle Agglutination test for ID - easier (need antigen only)
105
vaccine for CAP via H. influenzae?
YES - type B
106
treatment CAP via H. influenzae?
```
beta lactams (amox, clav. acid)
if resistant, 3rd gen cephalosporin
```
107
when will H. influenzae lyse RBCs?
requires comorbid infection to lyse RBCs
108
describe Mycoplasma pneumoniae
```
smallest living free bacteria
lack cell wall
FRIED EGG APPEARANCE
membrane has STEROLS
stain poorly (no cell wall)
pleomorphic shape
```
109
symptoms w/ atypical CAP M. pneumoniae?
non productive cough x1-2 months w/ fever, crackles, HA, chest pain
110
treatment P. aeruginosa?
DOC = cefipem + levofloxacin
* MDR strains common
* AVOID broad spectrum antibiotics
* Must do susceptibility testing
111
treatment CAP M. pneumoniae?
DOC = azithromycin, tetracycline
112
CAP VF M. pneumoniae?
adheres to epithelium, releases H2O2 - damage
| evades immune system by fusing to host cells w/ sterols
113
which age group does CAP C. pneumoniae primarily affect?
age 60+
114
describe C. pneumoniae
```
tiny, non-motile
G- coccoid
obligate intracellular parasite
two forms: EB (infects), RB (replicates)
two exotoxins
```
115
which part of lungs primarily affected by C. pneumoniae?
unilateral lower lobe, direct tissue destruction
116
diagnosis CAP C. pneumoniae?
clinical
cell culture/microscopy
SEROLOGY/PCR
117
treatment CAP C. pneumoniae?
DOC = erythromycin, tetracycline
118
describe L. pneumophilia
```
thin, pleomorphic
G- bacilli
fimbriae
polar flagellum
survives intracellularly
FACULTATIVE
produces beta-lactamase
catalase & oxidase positive
```
119
CAP VF L. pneumophilia?
survives intracellularly
prompts immune system to take them in via opsonization
replicates in phagosome, kills cell via lysis when bacteria released
120
diagnosis for CAP L. pneumophilia?
GOLD STANDARD = CULTURE, buffered charcoal yeast extract (BCYE)
rapid test for antigen in urine (serotype 1)
121
treatment CAP L. pneumoniae?
DOC = levofloxacin
| --> no tx for pontiac fever, supportive only
122
describe pseudomonas aeruginosa
G- bacilli
pili
aerobic
motile
123
CAP VF P. aeruginosa?
Pyocyanin = catalyses ROS production (tissue damage)
Pyoverdin
Exotoxin A = inhibits protein synthesis, ciliastasis, immunosuppresion
Elastase = breaks down lung elastin (LAS A, LAS B = synergistic)
Alginate = mucoid slime layer for adherence, inhibits ciliary escalator, antiphagocytic (inhibits complement & antibody binding)
LPS = endotoxin
pili = attach to host
124
because it is not very virulent, which CAP pathogen is most often in compromised pts only?
Pseudomonas aeruginosa
125
diagnosis P. aeruginosa?
needs isolation/ID - BAP & MacConkey media
water soluble blue green pigment
fruity smell
fluorescent tinged sputum
126
treatment P. aeruginosa?
DOC = cefipem + levofloxacin
* MDR strains common
* AVOID broad spectrum antibiotics
* Must do susceptibility testing
127
describe M. tuberculosis
```
slender, slightly curved
acid fast
rod shaped bacilli
obligate aerobes
non-motile
heat sensitive (killed w/ pasteurization)
NO GLYCOCALYX
```
128
two other agents that cause Tb
M. bovis (milk)
| M. africanum (W. Africa)
129
Tb VF?
Mycolic acid = resistant to dehydration, long chains fatty acid, resistant to H2O2
Cord factor = produces parallel growth of bacteria ("serpentine" cords), in virulent strains
sulfatides = glycolipid that inhibits phagolysosomes in macrophage, promote facultative intracellular growth
LAM = interferes w/ INF-gamma production, inhibits cell mediated immunity, scavenges ROI
130
what types of cells make up granulomas?
MTB cells +
| macrophages, fibroblasts, multinucleate giant cells, collagen fibers
131
reservoir for MAC non-TB?
ubiquitous - soil, plants, water, etc
132
what happens after sensitization in a TB infection?
```
granulomas form
+ TST
+ IGRA
macrophages activated
sensitized t cells release lymphokines, IFN-gamma, activate macrophages
```
133
What cultures are ONLY used for TB?
Middlebrooks & Lowenstein-Jensen agar
134
in a broth culture, where do cells clump in TB?
top of test tube (fatty chains)
135
What stains are done for TB?
```
acid fast (Ziehl-Neelsen or Kinyoun stain)
fluorescent stain (Rhodamine) - preferred
```
136
how are TB colonies described in a Lowenstein-Jensen agar culture?
"ruff, buff, & tuff"
137
what is a lymphokine?
LMW protein secreted by T cells in response to stimulation by antigens, activate macrophages and lymphocytes
138
what lymphokine is activated in TB?
IFN-gamma
139
treatment MAC non TB?
HEART (highly effective antiretroviral therapy)
no isolation bc its not infectious
both HIV+ and HIV- get combo:
--clarithromycin &/or azithromycin + EMB + RIF (rifampin for HIV-, rifabutin for HIV+)
HIV - should continue until sputum cultures neg for 1 yr
HIV+ w/ MAC infection = without immune reconstitution treatment is lifelong OR treatment for 2 weeks then HEART/HAART/ART (DO NOT START TREATMENT & ART AT SAME TIME - can get IRIS)
HIV+ w/out MAC infection = chemoprophylaxis w/ CD4 100
140
describe miliary TB?
results from progressive prim. infection or LTBI that spread (can spread to other organs)
millet-seed sized granulomas
organ/system function lost due to proliferation of TB
141
describe Pott Disease (TB)
MTB in VERTEBRAL BODIES
chronic back pain
if untreated, destruction of vertebrae, permanent disability
142
diagnosis of TB?
rapid molecular detection (Xpert, MTB/RIF system) = PCR
| need 2 ml sputum sample
143
pathogens for non-TB mycobacterial infections (MAC)
M. avium & intracellulare
144
describe MAC non-TB
acid fast
G+
aerobic
bacilli
145
colonies of MAC non-TB?
flat, small, translucent, smooth, pale yellow pigment, NO cording/clustering
--use Middlebrook agar
146
MAC non-TB VF?
intracellular growth
lack granuloma formation even though intracellular growth
no overgrowth
resistant to disinfection
147
reservoir for MAC non-TB?
ubiquitous - soil, plants, water, etc
148
how is MAC non-TB spread?
NO person to person
| INHALATION
149
which pts particularly susceptible to NTM infections?
HIV+ pts
150
describe HIV - clinical manifestations of MAC non-TB?
immunocompromised pts
often preexisting conditions
--fibrocavitary disease - elderly men, COPD, hx smoking/alcohol)
--fibronodulary disease - elderly women, bronchiectasis, repressed coughing
lymphadenitis kids 1-4 y.o. - involves unilateral cervical nodes
151
what symptoms are different for HIV+ MAC compared to HIV - MAC?
DIARRHEA - initial infection = colonization of GI tract, then spreads to other organs
152
describe HIV+ clinical manifestations of MAC non TB?
granulomas not effective
organs enlarge
large #s WBCs (macrophages, blood)
new infection
can involve any tissue - lymphohematogenous spread
can't develop CMI, no activation macrophages/granulomas
153
what are CD4 levels of HIV+ MAC non TB pt?
CD4 levels < 50 cells/microliter
154
diagnosis MAC non TB?
```
clinical consistent w/ NTM
exclude other etiologies
sterile site isolation MAC
CXR
PCR for 16s rRNA pathogen sequence
```
155
treatment MAC non TB?
HEART (highly effective antiretroviral therapy)
no isolation bc its not infectious
both HIV+ and HIV- get combo:
--clarithromycin &/or azithromycin + EMB + RIF (rifampin for HIV-, rifabutin for HIV+)
HIV - should continue until sputum cultures neg for 1 yr
HIV+ w/ MAC infection = without immune reconstitution treatment is lifelong OR treatment for 2 weeks then HEART/HAART/ART (DO NOT START TREATMENT & ART AT SAME TIME - can get IRIS)
HIV+ w/out MAC infection = chemoprophylaxis w/ CD4 100
156
cause polio?
Picorna virus
157
what causes paralysis to nervous system w/ polio?
3 antigenic variations - must be resistant to all 3
158
5 clinical syndromes of polio?
1. inapparent infection
2. abortive illness
3. non-paralytic poliomyelitis
4. paralytic poliomyelitis
5. post polio syndrome
159
describe polio: inapparent infection
asymptomatic to minor malaise
| 90-95% infections
160
describe polio: abortive illness
fever, malaise, N/V, drowsiness, HA
| 4-8% infections
161
describe polio: non-paralytic poliomyelitis
fever, malaise, N/V, drowsiness, HA, stiff neck, stiff back
| 1-2% infections
162
describe polio: paralytic polio
flaccid paralysis from LMN damage
| <1% infections
163
describe rabies: paralytic phase
coma, HTN, death
164
prevention polio?
vaccines:
IPV
eIPV (used in US)
OPV (no longer used because of VAPP, back mutation of live attenuated virus)
165
treatment polio?
PREVENTION
166
is polio still present?
mostly eradicated, now in Syria
167
cause of Arbovirus?
arthropod-borne viruses (mosquitos, ticks)
| --humans = dead end hosts usu
168
describe Togaviridae group of Arboviruses
ss+RNA
small
enveloped
Alphavirus: Eastern/Western/Venezuelan Equine Encephalitis
Flavivirus: St. Louis Encephalitis, WNV, DENGUE FEVER
169
describe Bunyaviridae group of Arboviruses
3 circular ssRNA segment genome
| - California excephalitis virus
170
describe symptoms Arboviruses
typically subclinical
| abrupt onset fever, HA, vertigo, photophobia, N/V, confusion, personality changes, seizures
171
diagnosis arboviruses
specific test for IgM antibodies
| -- ELISA serum or CSF (serum shows prior infection + Yellow Fever, CSF shows encephalitis cause)
172
treatment arboviruses
symptomatic only
173
how to stop arboviruses?
stop chain of transmission
| - eradicate vectors, avoid exposure
174
cause Rabies?
rhabdovirus
175
describe rhabdovirus/Rabies
ssRNA
enveloped
bullet shaped
176
describe course Rabies infection?
1. prodrome
2. excitatory phase
3. paralytic
177
describe rabies: prodrome
mild fever, pharyngitis, HA, pain, burning, increased sensory sensitivity
178
describe rabies: excitatory phase
anxiety, apprehension, hydrophobia
179
describe rabies: paralytic phase
como, HTN, death
180
how long does rabies incubate?
can be 2 wks to years!
181
diagnosis rabies?
hx of bite + symptoms in pt
182
treatment/protocol for rabies?
```
initiate post-exposure prophylaxis (RABIES VACCINE = HDCV + hyperimmune serum)
kill/examine animal - do DFA test
quarantine healthy dogs/cats
kill examine strays immediately
halt treatment if animal neg for virus
EXTRA CAUTIOUS w/ BATS
```
Milwaukee protocol = fails as much as succeeds
183
animals w/ rabies in US?
domestic dogs
| feral skunks, raccoons, foxes, bats
184
how to get rabies?
animal bite - also documentation of aerosol transmission (ie: in a bat cave)
(cryptic rabies = majority of cases since 1990)
