Neuro: Test 1 : 22&23. Dugan : Bacterial Cns Infection I&ii

Front 1

define meningitis

encephalitis:

Back 1

meningitis:inflammation of the pia-arachnoid membranes

encephalitis: inflammation of the brain

Front 2

pt comes in with a fever, nuchal rigidity, some altered mental status, but says I am having the most severe headache of my life...

*

Back 2

Acute Meningitis

Front 3

please list the 3 most common causes of bacterial meningitis today

affects who mostly?

*

Back 3

most: strep pneumoniae-adults

N. meningitidis- young adults (college)

H. influenzae- elderly and infants (who don't have Hib vaccine)

NOTE: you will still likely see s.pneumoniae as the leading cause in elderly, but if you see h. influenzae it will be in an old fart

Front 4

please list the shape, G-/+, catalase -/+, and if Streptococci is able to ferment sugar

Back 4

Gram positive cocci in chains

Catalase negative

Ferment sugars → lactic acid → low pH

Need enrichment with blood to support growth

Front 5

S. agalactiae is also known as group B strep...what type of Hemolysis does it under go?

what is strep pyogenes known as? what type of hemolysis does it undergo?

what type of hemolysis does s. pneumoniae undergo? *

Back 5

s. agalactiea: beta hemolysis

s. pyogenes (group A strep): beta hemolysis

s. pnuemoniae: alpha

Front 6

what are 3 lab tests that can show s. pneumoniae?

Back 6

Optochin S
Bile solubility pos
Quelling test pos

Front 7

this can cause septicemia, meningitis, and pneumonia and Infect neonates during vaginal delivery. What is it? What is the capsule like?

Back 7

Group B Streptococcus (Streptococus agalactiae)

Sialic acid capsule similar to E. coli K1

Front 8

Gram positive, lancet shaped, diplococci with a polysaccharide capsule

Back 8

Streptococcus pneumoniae

also has pneumolysin and C substance (choline and teichoic acid)
C-substance + C-reactive protein → activates

Front 9

Gram negative diplococci, coffee bean shape

Oxidase positive - produce cytrochrome oxidase (aerobic)

Describes?

Back 9

Neisseria

Front 10

most common serotypes of neisseria meningitidis in the US

Back 10

B and C

others are: A, Y, W135

Front 11

major virulence factors of N. meningitidis ?

Back 11

Pili
Capsular polysaccharide (remember, gonorrhea does not)
Lipooligosaccharide (LOS)
Outer membrane proteins
IgA protease

Front 12

Small, Gram-negative, pleomorphic, fastidious rods

Back 12

Haemophilus influenzae

Front 13

H. influenza requires what to grow in culture?

Back 13

X factor - hemin
V factor - nicotinamide adenine dinucleatide (NAD)
Provided by chocolate agar (red blood cells lysed by heating)

Front 14

if a child has immigrated and looks like they have meningitis, what was the likely cause?

Back 14

Haemophilus influenza

didnt get the Hib vaccine

Front 15

Intracellular parasite of macrophages causes meningitis in newborns and elderly

Associated with food poisoning with symptoms of gastroenteritis

bug? Gram +/-? Rod/Cocci?

Back 15

Listeria monocytogenes

short gram + rod

Front 16

primary virulence of Listeria monocytogenes?

Back 16

Virulence due to listeriolysin O (pore forming cytolysin): allows organism to escape phagocytic vacuole

Front 17

In pregnant woman this presents as mild genital infection with flu-like symptoms..bug?

Back 17

Listeria monocytogenes

Front 18

a meat company has to recall a number of cold-cuts because they are causing food-borne illness...cause?

Back 18

Listeria monocytogenes

Front 19

Distinctive tumbling motility when grown at 25oC

Back 19

Listeria monocytogenes

Front 20

which meningitis agent is most likely to cause rash?

Back 20

Neisseria meningitidis

can lead to septisemia and gangrene

Front 21

pathogenesis of meningitis?

Back 21

Colonization of the oropharynx
Organism enters blood stream through the mucous membranes
Resist killing primarily by capsule formation and other evasive mechanisms and multiply
Penetrates blood-brain barrier at the choroid plexus
Inflammation on blood side → spillage into CNS
Correlated with microbial load in blood (>105 org/ml)

Front 22

how can meningitis survive in the CNS?

Back 22

Reduced host defenses in CSF compared to blood → low levels of complement and antibodies → reduced phagocytosis
Bacteria survive and grow in the cerebral spinal fluid

Front 23

why is pnuemococcus the leading killer of bugs that cause meningitis?

Back 23

in meningitis the CSF becomes thick and causes pressure

pneumococcus is the best at doing this

Front 24

if you suspect meningitis, what should you do first

brain image
initiate antimicrobial therapy

Back 24

initiate antimicrobial therapy

Front 25

in bacterial meningitis, what will you see in your CSF obtained from lumbar puncture?

Cell type
Glucose
Protein
Stained Smear
Result of Culture

Back 25

>50% PMNs

reduced glucose (bacteria eating it up)

>100 protein (permeation of BBB, allowing more albumin into spinal fluid)

Stained smear usually positive

result of culture is usually positive

Front 26

Back 26

Front 27

Virulence Factor of Common Meningitis Causing Bacteria?

Back 27

Polysaccharide capsule

(Sialic acid found in N. meningitidis group b, E. coli K1 and Group B Strep)

Front 28

Emperic DOC for Meningitis?

Back 28

vancomycin + cefotaxime or ceftriaxone + dexamethazone

Front 29

tx for S. pneumoniae (Pen sens)

Back 29

Penicillin G

Front 30

tx for S. pneumoniae (Pen resist)

Back 30

Vancomycin or linezolid

Front 31

tx for N. meningitidis

Back 31

Penicillin G

Front 32

tx for H. influenza betalactamase pos

Back 32

Cefotaxime or ceftazidime

Front 33

tx for Grp B Streptococcus

Back 33

Penicillin G

Front 34

Chemoprophylaxis for N. meningitidis?

(intimate contacts)

Back 34

DOC: rifampin

Front 35

Immune response of polysaccharide vaccine versus conjugate vaccine

what is the difference?

***

Back 35

polysaccharide: B cell initiated leads to IgM formation (lack memory, T cells, can't do boosting)

conjugate: T and B cells formed, get memory and IgG

Front 36

Due to a rupture of a superficial infective focus in subarachnoid space
Ocular palsies in ~½ of cases
Lab Diagnosis:
Lymphocytic pleocytosis in CSF
Usually 100-200 WBC’s
CSF cultures (need 10-20 ml)
Conversion on skin test (most often not helpful)

Back 36

Tuberculosis Meningitis

REMEMBER: HIV PTs LIKELY TO HAVE TB

Front 37

bug for lyme dz?

Back 37

Borrelia burgdorferi

Front 38

test that has to be done to confirm treponema pallidum (syphilis) meninigitis?

Back 38

VDRL on CSF,

if pos confirm with FTA: include with aseptic meningitis workup

Front 39

pt has multiple erythema migrans, presents as viral meningitis, have headache > 5 days, and cranial neuritis (cranial nerve palsy or papilledema). What is going on and what is the tx?

Back 39

Lyme Meningitis (Borrelia burgdorferi)

DOC for Lyme meningitis: ceftriaxone

Front 40

what normally causes brain abscesses?

how does this occur?

should you draw CSF to diagnose?

How will it present?

Back 40

anerobic bacteria (staph a)

chronic infections that have spread to the brain (mastoids, sinuses, that spread)

lumbar puncture CONTRAINDICATED

A focal infection of the brain parenchyma that causes specific focal deficits