Bacterial Inf. of CNS

Question 1

What are predisposing factors for a Meningococcal meningitis infection?

Answer 1

History of URTI
Complement deficiencies
Outbreaks most common in winter within schools and barracks.

Question 2

What are the hallmarks of a bacterial infection of the meninges?

Answer 2

Presence of neutrophils
Decreased glucose
Increased protein
Increased pressure

Viral meningitis will display the opposite of all of these and presents with monocytes/ lymphocytes instead of neutrophils.

Question 3

What are the two agents that cause the most cases of bacterial meningitis in the US?

Answer 3

S. pneumo is #1
N. Meningitidis is #2
Listeria is seen in the very young and the very old.

Question 4

What population is Group B strep (s. agalactiae) seen in?

Answer 4

Seen in very young newborns aged less than 2 months old.

Question 5

Pneumolysin and IgA protease are seen in what species of meningal bacteria and what are the functions of the enzymes?

Answer 5

Pneumolysin and IgA protease are seen in S. pneumo

Both of these virulence factors prevent clearance from the respiratory tract by destroying epithelial cells and degrading IgA.

Question 6

What S. pneumo virulence factor aids in dissemination oof the organism?

Answer 6

Thick polysaccharide capsule interferes with phagocytosis and provides complement protection.

Question 7

A positive Latex agglutination test with meningitis is proof of what?

Answer 7

Proof of the presence of capsular antigens (S. pneumo)

Question 8

What are the recommended treatments for S. pneumo meningitis?

Answer 8

1/3 of S. pneumo are resistant to penicillin thus vancomyocin and cephalosporin should be used for at least 10-14 days.

Question 9

Describe the 23 variant S. pneumo vaccination

Answer 9

This is a polysaccharide vaccination covering 23 variants. It is not very effective in children less than 2 years old and isnt really used much anymore.

Recommended for adults older than 65
and in persons >2 years with medical complications.

Question 10

Describe the 13 variant S. pneumo vaccination

Answer 10

The 13 variant is a conjugated polysaccharide vaccine conjugated with the diptheria toxoid.

Good to used in infants and young children 90% effective!

Not as effective against pneumonia and otitis media but recommended for routine vaccination of children at months 2, 4, 6 with a booster at 12-15 months.

Question 11

If you see a gram negative coffee bean shaped diplococcus in CSF you should think of what organisms?

Answer 11

Neiserria Meningitidis

Question 12

What is the N. meningitidis endotoxin called?

Answer 12

LOS lipooligosaccharide differing from LPS with shorter side chains and no repeating polysaccharides.

Lipid A and core oligosaccharides similar to LPS.

Question 13

Why is N. meningitidis vaccination reccomended for travelers?

Answer 13

Because it is endemic to sub-Saharan Africa

Question 14

Why is N. meningitidis seen mostly in schools and barracks during the winter months?

Answer 14

Because it is spread by aerosolization and thus in close locations indoors it spreads easily.

Question 15

How many serotypes are there of N. meningitidis??

Which is most common in children?

Answer 15

5
C,B,Y,W-135,A

Type B is most common in children as there isnt a good way of vaccinating against it.

Question 16

If you see meningitis bacterial with loss of limb or digits what should you think of?

Answer 16

N. meningitidis

Question 17

If you see bacterial meningitis with petichial rash think of this…

Answer 17

N. Meningitides!

Question 18

How does N. meningitidis cross the BBB

Answer 18

Through neutrophils

Leads to endotoxemia organ failure and DIC.

Question 19

How is N. meningitidis treated?

Answer 19

Treated with penicillin!!!!

But prior to identification you still want to treat with Vancomycin and cephalosporin.

Question 20

What strains are covered by the tetra valent N. meningitides vaccine?’
(MPV4)

Answer 20

This Vaccine covers all strains except for B and therefore is not effective in children less than 2 years of age.
This is just a polysaccharide vaccine and thus has a very weak response used in last resort efforts in those over 55 years old or in travel.

Question 21

How is the meningococcal conjugate vaccine used?

Answer 21

This vaccine is conjugated with diptheria toxoid and is used in ages 11-55 but is also approved for those ages 1-55 of increased risk.

It covers all serotypes except for B and has a much better antibody response.

Question 22

In October two Serotype B meningococcal vaccines were developed, what do these vaccines contain?

Answer 22

These vaccines contain recombinant proteins and are safe and efective in adolescents and young adults but remains very expensive.

Question 23

Group B stress is seen mostly in what population of patients?

Answer 23

Most often seen in neonates that are less than 2 weeks old!

Early onset is within the first week and late onset is 1-3 weeks after birth.

Question 24

What is the largest risk factor for neonates contracting group B strep?

Answer 24

Mothers who have a GBS colonized vagina prior to birth.
These women are 25 more likely to cause infants to be born with GBS.

Absence of maternal immunoglobulin is also a risk factor.

Question 25

What is the drug of choice for treating GBS meningitis?

Answer 25

Penicillin!!!

Question 26

How is GBS meningitis prevented?

Answer 26

Universal screening of all pregnant women as well as intrapartum antibiotic (penicillin) delivery >4 hours before delivery.

Question 27

Prior to vaccination, what percentage of invasive disease was due to H. influeanzeae?

Answer 27

95%! due to type B

Question 28

What do the encapsulated strains of H. influenzae cause?

Answer 28

Meningitis and epiglottis

If you see epiglotitis expect H. influenzae.

Question 29

What is unique to H. influenzae type B meningitis symptoms?

Answer 29

Causes hearing loss!

Very rarely seen due to vaccination so expect a foreigner to have it.

Question 30

What is the name of the neurotoxin produced by tetanus?

Answer 30

Tetanospasmin

Spore appears as a drumstick under the scope.

Question 31

Neonatal tetanus is typically spread through what anatomical structure?

Answer 31

Spread through bad tools to the umbillical stump.

Question 32

What sort of toxin is tetanus toxin?

Answer 32

Its and A-B toxin that binds to motor neurons and is transported to the spinal cord where it will irreversibly inhibit the release of inhibitory neuro transmitters causing Spastic Paralysis.

Question 33

What is the treatment for Tetanus?

Answer 33

Immunoglobulin (Passive treatment)

Toxoid vaccine (active treatment)

The goal is to remove any unbound toxin.

Question 34

How does the botulism toxin work?

Answer 34

Is an A-B toxin that inhibits Acetylcholine release causing flaccid paralysis.