Exam 1 micro Flashcards
Typical and atypical pneumonia on cheset xray
typical-lobar
atypical-interstitial
Most common pneumonia bacteria
strep pneumo
Pneumonia in unvaccinated children
H. influenza
also see otitis media
Encapsulated organisms (6)
Some killers have pretty nice capsules Strep pneumo Klebsiella H. flu Pseudomonas Neisseri meningitidis Cryptococcus neoformans
Opzonization
IgG and C3b
increases phagocytosis 4000 fold
Reason for neutrophils in pneumonia
teichoic acid recruits via C5a
Use of auramine rhodamine stain
acid fast screening
needs confirmation with acid fast
CD4 count and opportunistic infections with AIDS
below 200 CD4 count
TB pathogenesis
inhaled, alveolar macrophages take up
inhibit lysosomal fusion, replicate in macrophage
Th1-> IFN alpha-> macrophage activation and granuloma formation
immune system causes damage, not TB
Cause of night sweats/cachexia for immune molecules
TNF alpha
Virulence factors of TB
cord factor inhibits WBC migration
tuberculin triggers cell mediated immunity
sulfatides prevent macrophage lysosomal fusion
Influenza’s virulence factors
hemagglutinen binds sialic acid on epithelium
neuroaminidase cleaves sialic acid/decreases mucus viscosity
Antigenic drift vs shift
drift-RNA pol causing mutations
shift-2 or more viruses form completely new virus
Cause of type I hypersensitivity
mast cell degranulation
Early asthma
involves mediators from mast cells/basophils
within minutes of exposure
Late asthma
leukocyte and cytokine mediated
IL4/IL5/TNFalpha/PAF involved
increased endothelial cell adhesion
chronic inflammation/tissue injury
Type III hypersensitivity
immune complexes deposited in tissues
activates complement
causes lumpy-bumpy bx of kidney
Type II hypersensitivity
tissue specific Abs to self
change in cell function or cytotoxic
linear/smooth bx of kidney
Type IV hypersensitivity
delayed
CD4 and cell mediated
macrophage and CTL activation
MS/Guillian Barre/Hasimotos/poison ivy
Most common bacterial atypical pneumonia
mycoplasma
Rhinovirus characteristics
naked + RNA labile in acidic pH uses ICAM-1 receptor most common cause of cold replicates at 33 degrees C
Coronavirus charge/genome/structure
enveloped
+ RNA
replicates at 33 degrees C
Pathogenesis of rhinovirus infection
ICAM-1 receptor attachment
damage epithelium
bradykinin/histamine release
Epiglottitis infection bugs
H flu. type B
S. pneumo
S. aureus
usually in kids
Coxsackie A pharyngitis
naked virus
herpangina types A2-A6
fecal/oral transfer
EBV pharyngitis
+ mononucleosis (splenomegaly)
in young adults/teens
exudative pharyngitis
fatigue/weakness
CMV pharyngitis
- mononucleosis
in older/sexually active pts
Parotitis
from mumps virus
- RNA enveloped
swollen parotids (bull neck)
low grade fever/myalgia/headache
Important complication of mumps
orchitis
sterility in post pubertal males
Parainfluenza virus laryngitis
stridor (barking cough)
types 1 and 2 are major cause
Steeple sign on x-ray
syncytia can form
Cause of most bronchitis
viral -> nonproductive cough
Respiratory syncytial virus
bronchiole infection of children/infants
tx with ribavirin (inhibits nucleic acid synthesis)
ribavirin is teratogenic
Difference b/t pneumonia and bronchitis
pneumonia has productive colored sputum with increased HR and fever/chills/SOB
Influenza virus
- segmented RNA enveloped virus A is humans/animals B and C are only humans hemaglutinin and neuraminidase M protein forms membrane channels
Genetic shift with influenza
only type A
Pathogenesis of influenza
causes increased fluid in lungs
drown in own fluid
Vaccine for influenza
killed or live attenuated
killed for pregnancy/immunocompromised
4 strains from prior year
Adenovirus
naked DNA
penton fibers attach and toxic to cells
pharyngoconjunctival fever/ARDS
serotypes 3,4,7 in live attenuated vaccine
Measles virus
- RNA enveloped
HN and F proteins
cough/coryza/conjunctivitis
koplik spots/maculopapular rash
Complications of measles
giant cell pneumonia
encephalitis
subacute sclerosing panencephalitis
Vaccine for measles
live attenuated
Hantavirus
segmented - RNA enveloped
tropism for pulmonary capillary endothelial cells
found in US Southwest
from rodent feces
Hantavirus sx phases
prodrome (fever/headache)
cardiopulmonary (dyspnea/pulmonary edema)
convalescent
SARS
+ RNA enveloped coronavirus
Hong Kong/Toronto
from civet cats
MERS
Middle East respiratory syndrome
from coronavirus
SARS sx
flu like prodrome
lower respiratory tract
