Lect 12 Flashcards
(61 cards)
1
Q
lobar pneumonia
A
involvement of the entire lobe
2
Q
what is PNA
A
inflammation of the lung parenchyma
3
Q
causes of PNA in people with no known predisposing factors
A
- mycoplasma pneumoniae
- streptococcus pneumoniae
- chlamydophila pneumoniae
4
Q
causes of PNA in alcoholics/vagrants
A
- streptococcus pneumonia
- klebsiella pneumoniae
5
Q
causes of PNA in people with underlying disease
A
- streptococcus pneumoniae
- H. influenzae
- pseudomonas aeruginosa
- staph. aureus
6
Q
causes of PNA in people with persons requiring ventilation
A
- klebsiella pneumoniae
- pseudomonas aeruginosa
7
Q
causes of PNA in people with travel/occupational exposure
A
Legionella pneumophila
8
Q
what is 6th leading cause of death and most common infectious cause of death
A
PNA
- mortality rate is 25% in infections requiring hospital admission
9
Q
PNA can be divided into what two groups
A
- hospital acquired (Nosocomial)
- develops 72 hours or more following admission
- community acquired (CAP)
- develops in people with limited or no contact with medical settings
10
Q
community acquired PNA can be divded into what two groups
A
- typical vs atypical
11
Q
typical CAP involves infection from which organisms
A
- S. Pneumoniae
- H. influenzae
- K. pneumoniae
- S. aureus
12
Q
atypical CAP involves infection from which organisms
A
- zoonotic
- nonzoonotic
- chlamydia pneumoniae
- mycoplasma pneumoniae
- legionalle pneumoniae
- usually have extrapulmonary involvement and cause systemic infections
13
Q
what types of ABx will not work against atypical PNA
A
- PCN because atypical PNA are unresponsive to B-lactams
14
Q
clinical presentation
- sudeen onset
- sick appearance
- high temperature (>103)
- productive cough
- pleurisy
- consoldiation on CXR
- CP, SOB
A
typical bacterial PNA
15
Q
clinical presentation
- gradual onset
- well appearance
- lower temperature <103
- non productive cough
- patchy infiltrates on CXR
- diarrhea, abd pain
A
atypical bacterial PNA
16
Q
streptococcus pneumoniae
- gram status
- shape
A
- gram positive
- lancet shaped diplococcus
17
Q
streptococcus pneumoniae: typical presentation on blood agar plate
A
-
alpha hemolytic colonies
- green colored colonies
18
Q
when does streptococcus pneumoniae occur (season)
A
occurs more colder, wetter months
19
Q
streptococcus pneumoniae incidence is in what patient populations
A
- young children
- adults > 65 yo
20
Q
reervoir for streptococcus pneumoniae
A
asymptomatic carriers
21
Q
streptococcus pneumoniae virulence factor (capsule)
A
- capsule
- inhibits phagocytosis
- interferes with complement activity
- prevents C3b opsonization of the bacteria
22
Q
streptococcus pneumoniae virulence factors (seen in gram positive bacteria)
A
- peptidoglycan-teichoic acid complex
- illicits a significant immune response
23
Q
virulence factor specific to streptococcus pneumoniae
A
- Pneumolysin
- interacts with target cell membrane
- forms transmembrane pores
- results in cell lysis
- activates complement
24
Q
streptococcus pneumoniae virulence factor: autolysin
A
- causes lysis of pneumococcus and results in release of pneymolysin and release of other virulence factors
- in response to antibiotic therapy and stationary phase
- attempt by organism to dampen host immune response by overwhelming it
25
how does consolidation form
* pneumococcus enters respiratory tract and multiples in tissue, stimulating immune response
* fibrinous edema fluid into alveoli followed by red cells and leukocytes
26
clinical presentation
* sudden onset of fever
* CP
* productive cough with **rust colored purulent sputum**
strep pneumoniae = pneumococcus
27
Pneumococcus is sensitive to
optochin sensitivity
28
what is the bile solubility test
* **bile will lyse S. pneumoniae**
* no effect on other a-hemolytic strep
29
What is the Quellung reaction
* function: to observe capsules
* If the reaction is positive, the capsule becomes opaque and appears to enlarge
30
how is pneumococcus diagnosed
* agglutination test for capsular polysaccharides
* genetic probe test
* looks for S. pneumoniae specific rRNA
31
DOC treatment of pneumococcus
Penicillin G
32
prevention against pneumococcus
* vaccines
* **23-valent capsular polysaccharide vaccine**
* recommended persons \> 65 yo
* **13-valent capsular polysaccharide vaccine**
* \>80% infections in childnre \< 6 yo
* accountable for 75% of strains of pcn-resistent pneumococcus
33
klebsiella pneumoniae can cause both
* **typical** CAP and nosocomial (hospital)
34
Klebsiella pneumoniae
* gram status
* shape
* motility
* gram negative
* bacillus
* non-motile
35
where is Klebsiella pneumoniae normally found
* normal flora of mouth, skin, intestines
36
Klebsiella pneumoniae causes pna is what patient populations
* alcoholics
* persons with DM
37
virulence factors of Klebsiella pneumoniae
* Primary: coated by a thick slimy **polysaccharide capsule**
* ****antiphagocytic
* prevents MAC-mediated lysis
* adhesins
38
which organism causes an aggressive **necrotizing CAP** with predilection for the upper lobes; leads to abscess formation and cavitation; often fatal even with Abx treatment
Klebsiella pneumoniae
* causes necrotic destruction of alveolar spaces, inflammation, and hemorrhage in lung
39
clinical presentation
* acute onset of high fever
* productive cough with thick, blood tinged **currant jelly sputum**
Klebsiella pneumoniae
40
how is Klebsiella pneumoniae diagnosed
* gram stain
* currant jelly sputum
* cxr - cavitation
41
Klebsiella pneumoniae is resistant to what type of abx
Klebsiella pneumoniae produces beta lactamase
42
DOC treatment of Klebsiella pneumoniae
* combination
* aminoglycosides
* 3rd generation cephalosporin
* fluoroquinolones
43
mycoplasma pneumoniae causes what type of PNA
atypical CAP
44
which organism that causes PNA lacks a cell wall and has a "fried egg" appearance in culture
Mycoplasma pneumoniae
45
Mycoplasma pneumoniae have plasma membranes that contain what compound
sterols
46
clinical presentation
* non-productive cough that lasts 1-2 months
* fevers, crackles, HA, CP
* relapses are common
Mycoplasma pneumoniae
47
virulence factors of Mycoplasma pneumoniae
* hydrogen peroxide
* damages epithelium
* prevents clearance of airway and results in colonization of airways
* evades immune system by fusing to host cell membrane through sterols
48
Mycoplasma pneumoniae can also cause what other conditions
* otitis
* rhinitis
* pharyngitis
* tracheobronchitis
49
Mycoplasma pneumoniae usually affects what age range
5-20 yo
50
reservoir of Mycoplasma pneumoniae
humans
* transmitted person to person via respiratory droplets
51
Mycoplasma pneumoniae diagnosis
* CXR: patchy infiltrates
* sputum culture
* cold agglutinin assay
52
DOC treatment of Mycoplasma pneumoniae
* azithromycin/tetracycline
53
chlamydophila pneumoniae causes what type of PNA
atypical PNA
54
chlamydophila pneumoniae
* gram
* motility
* shape
* gram negative
* non motile
* coccoid
55
chlamydophila pneumoniae exists in what two forms
* \*\* obligate intracellular parasites
* 2 forms
* elementary body: infectious form
* reticulate bodies: intracellular form
56
chlamydophila pneumoniae causes PNA via what process
* result of direct tissue destruction during bacterial replication, in addition to inflammatory response
57
primary immune response to chlamydophila pneumoniae is done via what cell
PMNs (immunity is not long lasting)
58
reservoir for chlamydophila pneumoniae
* humans
* transmitted person to person via respiratory droplets
59
chlamydophila pneumoniae mainly affects what patient population
adults \>60 yo
60
chlamydophila pneumoniae diagnosis
cell culture and microscopy
61
DOC chlamydophila pneumoniae
* tetracycline/erythromycin
