Exam 2 Micro Flashcards
Coccidioides immitis characteristics
Southwest US (Jan Joaquin Valley)
Spherules in yeast form
KOH prep dx
Tx for dimorphic fungi
ketoconazole/fluconazole normally
amphotericin B for pregnancy
Blastomyces dermatitidis characteristics
Ohio/Mississippi Rivers
broad based budding yeast
can disseminate into CNS
Histoplasma characteristics
Ohio/Missouri/Mississippi basins
bird/bat droppings/cave diving
intracellular in WBC
Paracoccidioidomycosis characteristics
Latin America
multiple broad based budding yeast
Aspergillosis
type I hypersensitivity
from A. fumigatus and flavus
opportunistic
Allergic bronchopulmonary aspergillosis
type III/IV hypersensitivity
pts with asthma and cystic fibrosis
aka Farmer’s Lung
damage from cytokines
Noninvasive pulmonary aspergillosis
aspergilloma
intertwined septate hyphae
in lung cavity
Invasive pulmonary aspergillosis
neutropenic pts (immunocompromised)
hemoptysis
rapidly fatal
Dx of aspergillosis
acute 45 degree branching hyphae
Zygomycosis/mucormycosis characteristics
acute/rapid progression ketoacidotic diabetics/leukemia pts black pus out of nose CNS infiltration nonseptate hyphae branching at 90 degrees
Stachybotrys chartarum characteristics
mycotoxin producing
wet wood/paper
asthma sx
hemoptysis/hemosiderosis
Pneumocystis jiroveci characteristics
AIDS pts below CD4 count of 200 atypical pneumonia binds receptors on macrophages dx with giemsa stain (dented helmets) or gomori methenamine silver stain
Paragonimus westermani characteristics
lung fluke undercooked crab/cray fish coffee bean shaped snail is intermediate host hemoptysis
Dx of paragonimus westermani
golden brown operculated eggs in sputum
Causes of typical pneumonia
Strep pneumo Klebsiella H. influenza Moraxella catarrhalis S. aureus
Dx of strep pneumo/virulence
alpha-hemolytic
optochin sensitive
gram (+) diplococci
IgA protease/pneumolysin/capsule
Strep pneumo vaccine
PPSV23-capsule types for adults
PCV13-conjugated for children/immunocompromised
Dx of klebsiella
currant jelly sputum
gram (-) rod
lactose + on MacConkey agar
Risks for klebsiella
alcoholism
ventilators
Dx of H. influenza
growth on chocolate agar needs heme (x) and NAD (v) gram (-) short fat rod
Staph aureus pneumonia
salmon pink sputum
empyema
shock/hemoptysis
Causes of atypical pneumonias
mycoplasma pneumo chlamydophila legionella coxiella burnetii viral
Dx of mycoplasma pneumo
large number of PMNs cold agglutinins (+)
Assc with mycoplasma pneumo
college/high school students
lack of seasonality
nonproductive cough
Chlamydophila pneumo
gram (-)
large number of PMNs
elementary body outside
reticulate body inside (replicates)
Legionella pneumophila
gram (-)
water units/AC units
intracellular in Macrophages
Dx of legionella
charcoal yeast agar (iron and cystein)
fluorescent Ab staining in urine
Nosocomial pneumonia causes
pseudomonas (assc with Burkholderia cepacia)
S aureus
H. influenza
enterics
Risks for pseudomonas pneumonia
cystic fibrosis
ventilation
Anaerobic pneumo causes/sx
fusobacterium and bacteroides
foul smelling sputum
Anthrax characteristics
gram (+) rod
box car shaped
polyglutamic acid capsule
antrhax toxin/endospores
Dx of yersinia pestis
coccobacillus gram (-) bipolar staining aka safety pin stain
Q fever cause
coxiella burnetii
gram (-) coccobacillus
intracellular
unpasteurized milk/cattle,sheep, goats
Francisella tularensis
gram (-) coccobacillus
rabbit fever
intracellular
growth on charcoal yeast or Cysteine/Glc blood agar
Tuberculosis characteristics
mycolic acid cell wall (acid fast stain)
cord factor has serpentine arrangement (virulence)
sulfatide prevents lysosomal fusion
causes TNF-alpha release
Dx of TB
auramine rhadamine stain/acid fast stain
Lowenstein-Jensen agar growth
PPD test (type IV HS)
MAC pneumonia
immunocompromised (low CD4 count)
acid fast gram (+) rod
Nocardia characteristics
gram (+)
weakly acid fast
branching filaments
dx on blood or chocolate agar (fluffy on culture)
Causes of otitis media
Strep pneumo
H. influenza
Moraxella catarrhalis
Strep pneumo dx/labs
lancet shaped gram (+)
alpha-hemolytic
optochin sensitive
bile soluble
Causes of epiglottitis
most commonly H. influenza
S. aureus
S. pneumo
S. pyogenes
Virulence factors of H. influenza
polyribitol phosphate capsule
IgA protease
endotoxin
Vaccine for H. flu
based on type B capsule
conjugated
Moraxella catarrhalis characteristics
gram (-) diplococci
beta-lactamase producing
causes otitis media
Pseudomonas labs/tests
blue/green color smells like grapes gram (-) rod fermentation (-)/oxidase (+) growth on chocolate and MacConkey
Strep pyogenes pharyngitis
enlarged LN
palatal petechiae
tonsillar hypertrophy
scarlet fever rash
Strep pyogenes tests/labs
gram (+) diplococci beta-hemolytic bactracin sensitivie PYR (+) catalase (-)
M protein tissues with crossreactivity
cardiac myosin
sarcolemmal membrane protein
synovium
articular cartilage
Nephrogenic strep pyogenes
children ages 6-10
immune complex deposition in kidneys/glomerulonephritis
follows pharyngitis/cellulitis
Sx of nephrogenic strep pyogenes
hematuria (cola colored)
periorbital edema
HTN
Cause of nephrogenic strep pyogenes rxn
nephritis assc plasmin receptor (NAPlr)
SPE B
Dx of strep pyogenes
ASO-titer
anti-DNase B
S. pyogenes pyrogenic toxins
A-D
A and C lysogenized
cause Scarlet fever
Clostridia diphtheriae characteristics
gram (+) rod
club like swellings on ends
tox gene (iron regulated)
inhibits elongation factor 2
Sx of diphtheriae
pseudomembrane that bleeds when removed
bull neck
conjunctivitis
Dx of C. diphtheriae
Loeffler’s/Tellurite agar
modified ELEK test
tox gene PCR
Bordatella pertussis virulence factors
gram (-) coccobacillus
filamentous hemaglutinin/pertactin bind ciliated cells
pertussis toxin inhibits Gi (increases cAMP)
adenylate toxin increases cAMP production
Stages of pertussis
catarrhal-highly contagious
paroxysmal-whooping cough
convalescence
Pertussis prevention
acellular vaccine
pertussis toxin + FH+ fimbriae + pertactin
Dx of pertussis
Regan-Lowe charcoal agar
DFA stain
Tx for pertussis
erythromycin
Tx for diphtheria
erythromycin/penicillin
