Bacterial infections of the CNS I Flashcards Preview

Year 1 Microbiology > Bacterial infections of the CNS I > Flashcards

Flashcards in Bacterial infections of the CNS I Deck (33):
1

What are predisposing factors to pneumococcal meningitis?

Pneumonia and chronic otitis media

2

What are predisposing factors to meningococcal meningitis?

History of recent URTI (viral), complement deficiencies

3

What percent of patients with bacterial meningitis present with fever, headache, and stiff neck?

50%

4

What percent of patients with bacterial meningitis will present with two of the following: fever, headache, stiff neck, altered mental status?

100%

5

What abnormalities in CSF are more indicative of bacterial infection as opposed to viral?

Presence of PMNs, decreased glucose

6

What is the most common cause of bacterial meningitis among all age groups?

S. pneumoniae (50%)

7

What is the most common cause of bacterial meningitis among kids less than 2 YEARS of age?

Group B strep

8

What is the most common cause of bacterial meningitis among kids less than 2 MONTHS of age?

S. agalactiae (GBS)

9

Which two pathogens predominate in teenage bacterial meningitis infections?

Neisseria and S. pneumo

10

What is the gram stain for S. pneumo?

Gram positive

11

What is the catalase test for S. pneumo?

Negative

12

Does S. pneumo have a capsule?

Yes, virulent strains have polysaccharide capsule

13

What is the hemolysis pattern for S. pneumo?

Alpha (green)

14

How do you distinguish S. pneumo from other alpha-hemolytic streptococci?

S. pneumo is optochin sensitive and sensitive to bile (lysed by bile)

15

What are the pneumococcal virulence factors?

1. Choline binding proteins 2. Pneumolysin 3. IgA protease 4. Polysaccharide capsule

16

What is the diagnosis for pneumococcal meningitis?

1. Clinical signs 2. Gram stain of CSF 3. Latex agglutination for capsular antigens 4. Cultivation, biochemical analysis, susceptibility testing

17

What is the treatment for pneumococcal meningitis?

1. Penicillin 2. Vancomycin with a cephalosporin 3. 10-14 days

18

What is the pneumococcal polysaccharide vaccine made of?

Purified polysaccharide capsular antigen from 23 types of pneumococcus

19

Is PPV effective in children less than 2 years of age?

No

20

What are the recommendations for PPV?

1. Over age 652. Over age 2 only with immuno suppression

21

What is the pneumococcal conjugate vaccine made of?

1. Conjugated to nontoxic diptheria toxin 2. 13 capsular serotypes

22

Which pneumococcus vaccine is recommended for children less than 2 years of age?

PCV13

23

What is the gram stain for Neisseria meningitidis?

Gram negative

24

What is the shape of Neisseria meningitidis?

Coffee or kidney bean diplococcus

25

What is the oxidase test for Neisseria?

Positive

26

What is the catalase test for Neisseria?

Positive

27

What sugar(s) does Neisseria ferment?

Oxidizes glucose AND maltose (N. gonorrheae only oxidizes glucose)

28

What are the clinical symptoms of meningococcal disease?

Abrupt onset of fever, hypotension, petechial rash

29

How does N. meningitidis gain entry into the CNS?

Crosses BBB within neutrophils

30

What is the diagnosis for meningococcal meningitis?

1. Clinical findings 2. Gram stain of CSF and/or blood - direct observation 3. Buffy coat analysis in peripheral blood smear in cases with only bacteremia 4. Cultivation, biochemical analyses

31

What is the treatment for meningococcal meningitis?

Penicillin, also empiric treatment with vancomycin and a cephalosporin

32

Which meningococcal meningitis vaccine is recommended in high-risk people over 2 years of age?

MPV, MPV4

33

Which meningococcal meningitis vaccine is recommended in people between the ages of 11 and 55?

MCV4 - diptheria conjugated