Lower Respiratory Infections Flashcards
Opsonizing Ig in alveoli?
IgG
**facilitates ingestion by macrophages
Only real way to differentiate between bronchitis and pneumonia?
infiltrates or consolidation on CXR
Most common cause of bronchiolitis?
RSV
Age where clinical sx of bronchiolitis develop?
infants and young children only
Diagnostic test for RSV?
nasal washing + antigen test
Respigram?
Ig reactive with RSV
palivizumab
humanized monoclonal Ab reactive with RSV
Mild type of influenza virus?
C
**almost everyone develops immunity by age 15
Infectious period for adults with influenza virus?
one day before onset of sx –> 5 days after sx onset
Sx to differentiate influenza virus from common cold?
high fever
Characteristic to differentiate influenza from atypical PNA?
rapid onset
Test for influenza?
rRT-PCR
real time reverse transcriptase PCR
Whooping cough bug?
Bordetella pertusis
Gram -
cocco-bacillus
Bordetella pertussis
Gram ?
shape ?
Gram -
cocco-bacillus
Tissue damaging VF of B pertusis?
AB-toxin
Atteachment VF of B. pertusis?
filamentous hemagglutinin
age for most severe pertusis?
Culture medium for B. pertusis?
Bordet-Gengou
Unusual WBC finding in pertusis?
lymphocytosis (vs high PMNs of other bacterial infx)
Tx for pertusis?
erythromycin
**not effective after ~2 weeks
Most common cause of CAP?
Strep pneumoniae
Three major bacterial causes of atypical PNA?
Mycoplasma
Chlamydia
Legionella
Viral cause of PNA in immunocompromised?
CMV
PNA age group:
Strep agalactiae
E. coli
neonates
birth - 6 weeks
PNA age group:
RSV
Mycoplasma pneumoniae
Chlamydia pneumoniae
Strep pneumoniae
6 weeks - 18 years
PNA age group:
Mycoplasma pneumoniae
Chlamydia pneumoniae
Strep pneumoniae
18 - 40 years
PNA age group:
Strep pneumoniae
Haemophilus influenzae
Anaerobes
Viruses
40 - 65 years
PNA age group:
Strep pneumoniae
Viruses
Anaerobes
Haemophilus influenzae
Gram (-) rods
> /= 65 yo
Most common HAP causes?
Gram (-) rods
S. aureus
Most common PNA in immunocompromised:
G - rods
Strep pneumo
fungi
filamentous bacteria
P. jiroveci
viruses
PNA causes in alcoholics:
Strep pneumo
Klebsiella pneumoniae
anaerobes
PNA in IV drug use:
S. aureus
PNA in post viral secondary infx:
S. aureus
PNA in chronic steroid use:
Nocardia
rhinovirus binds to?
ICAM-1 on resp epithelial cells
parainfluenza virus VF forming multinucleated giant cells?
F surface protein
croup
parainfluenza virus
Influenza virus types with 8 segments of RNA?
A and B
Influenza types with no animal reservoir?
B and C
What is required for antigenic SHIFT?
animal/human reservoir with simultaneous infx from two different strains of influenza
Influenza virus capable of genetic DRIFT and SHIFT:
A
Test for influenza?
rapid antigen test on nasopharyngeal swab
What is detected on influenza rapid antigen swab?
HA type via RBC agglutination
myocarditis
Coxackie B
herpangia, hand-foot-mouth disease
Coxackie A
Potential vector for gene therapy
Adenovirus
Three viruses that utilize hemagglutinin for binding:
influenza
parainfluenza
adenovirus
viral conjunctivitis
adenovirus
hemorrhagic cystitis
adenovirus
S. pyogenes
? hemolytic
bacitracin ?
ASO
Ab present?
Beta-hemolytic
bacitracin sensitive
ASO +
anti-streptolysin O
Second most common cause of PNA in pts w COPD?
Moraxella catarrhalis
Most common cause of PNA in pts w COPD?
non-typeable H. influenzae
attachment VF for M. catarrhalis:
pili
M. catarrhalis
Gram ?
VF for inflammatory response
gram -
endotoxin
Tx for M. catarrhalis?
amoxicillin-clavulanate
2nd linde: 2nd/3rd gen cephalosporin
whooping cough bug
Bordetella pertusis
B. pertussis VF’s for:
attachment?
impairs phagocytosis?
filamentous hemagglutinin
AB toxin –> increased cAMP
Bordet-Gengou
B. pertusis
Strep pneumo VFs for:
evading phagocytosis ?
capsule
IgA protease
S. pneumo
Optochin ?
? hemolytic
suceptible to optochin
alpha-hemolytic
Difference between H. influenzae type B and non-typeable:
HiB is encapsulated –> invasive
NTHi not encapsulated –> local infx
X factor and V factor on chocolate agar?
H. influenzae
H. influenzae
Gram ?
negative
Tx of H. influenzae?
3rd gen ceph
prophylaxis for close contacts of H. influenzae?
rifampin
RSV attachment VF:
G surface protein
Tx of severe RSV?
ribavirin
Most common cause of meningitis in newborns?
Strep agalactiae
Gram +
neonatal pneumonia
Strep agalactiae
beta-hemolytic
bacitracin resistant
“walking pneumonia”
Mycoplasma pneumoniae
Cold hemagglutinin
fried egg appearance
pneumonia in young person living in a dorm or similar
how would you treat it?
Mycoplasma pneumoniae
Erythromycin or tetracycline (no cell wall so no beta lactams)
intracytoplasmic inclusions on Giemsa stain
Chlamydia pneumoniae
Tx for Chlamydia pneumoniae?
Doxycycline
Most likely patient for C. pneumoniae infx?
young adult
S. aureus VFs for host defense evasion?
protein A
coagulase
hemolysins
leukocidins
S. aureus VFs for deeper systemic invasion?
hylauronidase
staphlokinase
lipase
Gram + cocci in clusters
S. aureus
Naturally inhabits water reservoirs
Legionella pneumophila
Silver stain positive
charcoal yeast extract
proliferates inside macrophages
Legionella pneumophila
pneumonia in pt with CD4 under 200?
silver stain positive
PCP pneumocyctic pneumonia
Pneumocytis jiroveci
beaded, filamentous growth in immunocompromised
can acid fast stain and look like TB
Nocardia asteroides
Forms caseous granulomas and PNA w cavitations +/- abcesses in kidney/brain
Gram +
aerobic
beaded filaments
Nocardia asteroides
Age group where S. pneumo is less likely cause of PNA?
neonates
birth - 6 weeks
Age where you might start seeing H. influenzae as a more common cause of PNA?
> 40
Age group less likely to have viral PNA?
18 - 40
anti-HA Abs on serology?
Parainfluenza virus
Influenza C has ___ segments in RNA.
7
Cytokines contributing to Influenza disease process?
IL-1
IFN-gamma
SS (+) Nonsegmented
non enveloped
icosahedral
Rhinovirus
Helical
enveloped
SS (-)
non segmented
Parainfluenza virus
Helical
enveloped
SS (-)
nonsegmented
F-protein –> multinucleated giant cells
RSV
Icosahedral
nonenveloped
SS (+) non segmented
Enterovirus
Coxackie A and B
DNA
Icosahedral
nonenveloped
liner DS genome
Adenovirus
Helical
Enveloped
SS (-) segmented (class V)
orthomyxoviridae
Influenza virus A B C
Two bacterial causes of conjuntivitis:
H. influenza
S. pneumo
Two bacterial causes of bronchitis that are not gram + or -:
Mycoplasma pneumoniae
Chlamydia pneumonia
Most common causes of “atypical PNA”
Mycoplasma
Chlamydia
Legionella
viral
Obligate intracellular bug that causes PNA and requires host ATP for energy?
Chlamydia
Inclusion body replication?
Chlamydia
Most common cause of bronchiolitis:
RSV
Age group you’re thinking about with RSV?
young
**almost everyone becomes immune after early life exposure
What does “catarrhal stage” refer to?
post incubation (3-21 days) stage of pertussis
lasts 1-2 weeks
What does “paroxysmal stage” refer to?
B. pertusis w/ severe and uncontrollable coughing
Regan-Lowe medium?
B. pertusiss
What won’t work to treat pertusiss?
cephalexin/penicillin
G - rods that could cause HAP?
Klebsiella
Pseudomonas?
E. coli?
Current Jelly sputum?
Klebsiella
Two bugs with positive silver stain?
Legionella
P. jiroveci
charcoal yeast
Legionella
hydrolyzes tributyrin
M. catarrhalis
four ways to Dx M catarahlis
hydrolyzes tributyrin
produces DNase
reduces Nitrite to Nitrate
does NOT ferment sugars
presence of cold hemagluttinin
Mycoplasma
fried egg
Mycoplasma
cysts forming dark oval bodies
P. jiroveci
Tx for Nocardia
TMP SMX