Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
|
gram positive cocci in chains
catalase negative ferment sugars- lactic acid- low pH need enrichment to grow (blood) |
s. pneumoniae
|
|
|
sialic acid capsule like E. coli
|
grp B strep
|
|
|
may be part of normal vaginal flora-> infect neonates during delivery
|
grp B strep
|
|
|
gram positive, lancet shaped diplococci
polysaccharide capsule- contributes to wet appearance pneumolysin c-substance |
grp B strep
|
|
|
neonate causes of meningitis
|
Gp B strep
e. coli strep pneumo |
|
|
up to 10yo
|
n. meningitidis
|
|
|
10yo-19 yo
|
n. meningitidis
|
|
|
20-60yo
|
strept penumo
|
|
|
elderly
|
strept penumo
|
|
|
diseases caused by S. pneumo
|
lobar pneumonia
otitis media sepsis sinusitis meningitis conjunctivitis |
|
|
fastidious, requires enriched growth medium and ↑ CO2
ox pos weak acidic products that cause characteristic patter on c trypticase |
n. meningitidis
|
|
|
gram negative diplococci, coffee bean shape
|
n. meningitidis
|
|
|
membrane proteins, IgA protease
|
n. meningitidis
|
|
|
small gram negative pleomorphic, fastidious rods
|
h. influenzae
|
|
|
polysaccharide capsule that is antiphagocytic
no demonstrable exotoxin, but endotoxin causes inflammation neuramidase IgA protease- breaks down IgA fimbriae |
h. influenzae
|
|
|
culture: hemin -X factor, V factor -NAD provided by chocolate agar
|
h. influenzae
|
|
|
meningitis, epiglotitis, wound infections, sepsis, arthritis
|
h. influenzae type b
|
|
|
intracellular parasite of MΦ causes meningitis in newborns and elderly
|
l. monocytogenes
|
|
|
assoc with gastroenteritis/food poisoning
|
l. monocytogenes
|
|
|
virulence due to listeriolysin 0 = 0 pore forming cytolysin to allow organism to escape vacuole
|
l. monocytogenes
|
|
|
is ingested with food that is contaminated and invades the small intestine and escapes to cause an infection- cold cuts, dairy products (grows at 4 degrees)
|
l. monocytogenes
|
|
|
clinical: pregnant women- presents as a mild genital infection with flu-like sx-> in utero infection causes stillbirth or death after birth; infection during birth causes meningitis and sepsis
adult disease causes meningitis in elderly or I/C- PMNs and GI sx |
l. monocytogenes
|
|
|
slender short gram pos rod
|
l. monocytogenes
|
|
|
distincitve tumbling motility at 25 degrees
|
l. monocytogenes
|
|
|
clinical symptoms of bacterial meningitis
|
abrupt onset of fever and severe headache with stiff neck and photophobia
+/- rash, nausea, vomiting severe cases: impaired conscious ness, delirium, seizures, neuro sx |
|
|
load in bacterial meningitis
|
>10^5 organisms/mL
|
|
|
entry of bacterial meningitis
|
organ enters blood stream through mucous membranes of oropharynx
penetrates BBB at choroid plexus inflammation on the blood side- spillage into the CNS |
|
|
spread and multiplication of bacterial meningitis
|
reduced host defenses in CSF compared to blood
-low levels of complement and Ab -reduced phagocytosis |
|
|
damage done by bacterial meningitis
|
clinical sx: due to inflammatory response
pus in subarachnoid space may spread over surface of brain, cerebellum, spinal cord fluid becomes thick (esp w/ pneumococcal) and causes blockage of foramina and ↑ in CSF pressure-> HA and nausea severe disease: neurological deficits caused by ↓ in cortical blood flow |
|
|
lab dx: ho wmany tubes do you need for bacterial meningitis?
|
3-4
3- cell count (last tube) 2- gram stain and culture 1- chemical analysis |
|
|
empiric tx of bacterial meningitis
|
vancomycin + ceftriaxone or ceftriaxone + dexamethazone
|
|
|
treatment
spneumo s pneumo pen resistant n. meningitidis h. influenza β lacatamase + grp B strept |
spneumo
-pen G s pneumo pen resistant -vanco or linezolid n. meningitidis -pen G h. influenza β lacatamase + -cefotaxime or ceftazidime grp B strept -pen G |
|
|
polysaccharide induces
|
T-cell independent response
-polysaccharide Ag causes IgM Ab but no memory response little boosting achieved |
|
|
conjugate vaccine
|
t-cell dependent response
-protein Ag cause IgG high affinity Ab adequate memory with boosting achieved |
|
|
focal infection of brain parenchyma that causes specific focal deficits
|
brain abscess
|
|
|
chronic meningitis due to TB
|
mycobacterium tuberculosis
rupture of superficial infective focus in subarachnoid space ocular palsies in about 50% of cases |
|
|
chronic meningitis due to syphilis
|
treponema pallidum
rare with secondary syphilis more common in HIV era |
|
|
examine for multiple erythema migrans
neurological symptoms in 1/3 of untreated cases presents like aseptic (viral meningitis) HA >5 days cranial neuritis |
chronic meningitis due to lyme disease
|
|
|
lymphocytic pleocytosis in CSF
-usually 100-200 WBC's -CSF cultures -conversion on skin test |
tb meningitis labs
|
|
|
VDRL on CSF, if pos confirm with FTA: include with aseptic meningitis workup
|
syphilis meningitis
|
|
|
>80% mononuclear
|
lyme meningitis
|
