Bacterial infections of the CNS I Flashcards
What are predisposing factors to pneumococcal meningitis?
Pneumonia and chronic otitis media
What are predisposing factors to meningococcal meningitis?
History of recent URTI (viral), complement deficiencies
What percent of patients with bacterial meningitis present with fever, headache, and stiff neck?
50%
What percent of patients with bacterial meningitis will present with two of the following: fever, headache, stiff neck, altered mental status?
100%
What abnormalities in CSF are more indicative of bacterial infection as opposed to viral?
Presence of PMNs, decreased glucose
What is the most common cause of bacterial meningitis among all age groups?
S. pneumoniae (50%)
What is the most common cause of bacterial meningitis among kids less than 2 YEARS of age?
Group B strep
What is the most common cause of bacterial meningitis among kids less than 2 MONTHS of age?
S. agalactiae (GBS)
Which two pathogens predominate in teenage bacterial meningitis infections?
Neisseria and S. pneumo
What is the gram stain for S. pneumo?
Gram positive
What is the catalase test for S. pneumo?
Negative
Does S. pneumo have a capsule?
Yes, virulent strains have polysaccharide capsule
What is the hemolysis pattern for S. pneumo?
Alpha (green)
How do you distinguish S. pneumo from other alpha-hemolytic streptococci?
S. pneumo is optochin sensitive and sensitive to bile (lysed by bile)
What are the pneumococcal virulence factors?
- Choline binding proteins 2. Pneumolysin 3. IgA protease 4. Polysaccharide capsule