Bacterial pathogenesis of infeciotn II Flashcards
Prevention of meningitis in high risk groups?
Use of prophylatic antibodies
Prophylactic meaning?
In order to prevent infection
When is penicillin not effective against meningitis?
Eliminating carrier state
Antibiotics for meningitis?
Sulfonamide, rifampin, sulfadiazine
Vaccine for meningitis?
Polyvalent given to kids >2yrs
Effective against all but group B serotype
Most important meningitis serogroup?
B
Which serogroup currently has no vaccine available for it?
B
Global prevalence of meningitis?
A mainly in tropics and africa/asia
B and C mainly in temperate regions
How are diff meningitis serogroups diff?
Serogroups differ in the sugar content of their capsule
How are meningitis vaccines designed?
Extract sugars from glycocalyx
What is a glycocalyx?
carbohydrate-rich, highly hydrated meshwork that covers the outer surface of many cells
Why can a vaccine not be made against serogroup B?
Issue w/ sugar content
Neisseria meningitidis causes of pathogenesis?
Ability to colonise nasopharynx
Ability to resist host defences
Expression of endotoxin
Why can neisseria meningitidis colonise the nasopharynx?
Bc of its pili
Why can neisseria meningitidis resist host defences?
capsule
Why can neisseria meningitidis cause toxic effects?
Endotoxin expression
Neisseria meningitidis virulence factors?
Endotoxin, capsule, pili, IgA protease, complement inhibitors
ROle of pili in neisseria meningitidis?
attachment to non-ciliated epithelial cells of host
Role of IgA protease in neisseria meningitidis?
Prevents opsonization by IgA on mucous membranes
Role of surface proteins on neisseria meningitidis?
Provide antigenic drift
Role of iron-scavenging protein on neisseria meningitidis?
Scavenges iron from host stores as Fe is needed by neisseria meningitidis for its own metabolic processes
WHich host stores can neisseria meningitidis get its iron from?
haemoglobin, transferrin and lactoferrin
Where are pili?
Extensions of the membrane that extend through the capsule
WHat is serogroup A’s capsule based on?
Mannose
