Bacterial CNS Flashcards
(28 cards)
What has decreased the incidence of meningitis?
Vaccines
What are the 3 community acquired bacteria that can cause meningitis?
S. pneumoniae
H. Influenzae
N. meningitidis
What is the classic triad of meningitis?
Fever
Excruciating Headache
Neck Stiffness
What is the appropriate treatment of Meningitis?
Prompt initiation of appropriate empiric therapy
Steroid to decrease swelling
Intrathecal Abx
Will you find a transudate or exudate in the CSF in meningitis?
Cloudy exudate with >5WBC’s
What are the Neonatal factors and the Maternal factors in Neonatal Meningitis?
Neonatal: immature host defense and immature organ systems.
Maternal: Urogenital infection (late) and intrauterine infection (early).
What are the S/S of Neonatal meningitis?
Addn’l?
Hyperthermia
CNS manifestations
GI disturbances
Respiratory abnormalities
Bulging fontanelle/ High pitch cry/ Paradoxic irritability. Crying when held and quiet when stationary
What are the 3 predominant Agents of Neonatal meningitis?
Strep agalactiae
E. Coli
Listeria moncytogenes
What is the most common cause of neonatal meningitis?
S. agalactiae
Group B streptococcus
Early onset disease: for Neonatal GBS
Obstetric complications are ______.
Sx’s develop within the first ___ days.
Major clinical manifestations are ________, __________, and _______.
Common
5 days
bacteremia, pneumonia, and meningitis
Neonatal GBS: Late onset:
obstetric complications are ___________.
S/x’s develop from ____ to _____ of age.
Major clinical manifestations are ________ infections, and ________ with fulminant meningitis
uncommon
7 days to 3 months
bone/joint/ bacteremia
Which strain of E. coli is encapsulated and associated with meningitis?
K1.
What bacteria has a Tumbling motility and grows at temperatures from 0-50 celsius, and is an intracellular pathogen?
L. moncytogenes.
What are the 2 cells that L. monocytogenes infect?
Epithelial cells
Macrophages.
What are the 2 virulence factors of Listeria moncytogenes?
1) LPS: antiphagocytic, causes hemolytic antibodies.
2) LLO: disrupts phagolysosome membrane, (-)’s Ag prduction. Causes apoptosis.
What are the 2 main manifestations of Listeria?
Sepsis and Meningitis.
Neonatal:Acquired inutero
Adult: leading cause of meningitis in Cancer and Renal transplant patients.
Brain stem encephalitis.
Hib contains what virulence factors?
Is Hib hemolytic?
LOS/ fimbriae/ Neuraminidase and IgA protease/ PRP capsule.
No it is not, but requires factors from RBC’s for growth.
What is the pathogenesis of Hib?
Nasopharynx–> epithelium–> blood or lymph–> CSF.
Which strain of Hib posses adhesins?
Non-encapsulated strains.
What is the treatment of Hib?
What is the Prevention of Hib?
Beta-lactams
6 different Hib conjugate vaccines.
What is the most common cause of bacterial meningitis?
S. Pnemoniae.
Alpha-hemolytic with green colonies.
Optochin sensitivity.
Encapsulated strains are virulent.
What would increase the risk of pneumoncoccal pneumonias?
Viral infections.
What are the virulence factors for pneumococcus?
Autolysin?
Pneumolysin?
IgA protease, H202, pili, peptidoglycan-teichoic acid, bacterial capsule.
Autolysin: lysis of of bacteria will release this to dampen host immune response.
Pneumolysin: forms pores in target cell, causes cell lysis and activates complement.
DIagnosis of S. pneumoniae?
Optochin sensitivity
Bile solubility test
Quellung reaction to observe capsules.
