-
Group B streptococcus (S. agalactiae)
Neonates
- #1 cause
- gram + cocci in chains, b-hemolytic, bactracin resistant
- normal flora of GI tract --> secondary spread to vagina
- neonates meningitis from colonized mother (delivery, infected amniotic fluid), if mother is group B + treat her during delivery
- fever, poor feeding, vomiting, irritability alterning w/ lethary
- PCR, latex particle aggluination, cAMP test, CSF: high protien, low glucose, neutrophils
- Rx: acyclovir, ampicillin + cefotaxime
-
E. coli
neonates
- Gram - rods, enterobacteriacea family, lactose +
- normal flora of GI tract --> secondary spread to vagina
- (2nd most common) neonates meningitis from colonized mother (delivery, infected amniotic fluid), K1 capsule
- fever, poor feeding, vomiting, irritability alterning w/ lethary
- PCR, latex particle aggluination, CSF: high protien, low glucose, neutrophils
- Rx: acyclovir, ampicillin + cefotaxime
-
Streptococcus pneumoniae
adults
- Sudden onset, fever, stiff neck, severe headache
- N/V, photophobia, confusion, sleepiness
- CSF: high protien, low glucose, neutrophils
-
Neisseria meningitidis
adults
- gram - diplococci inside polymorphonuclear cells, Capsule- A, B, C, Y, W 135, (B is the most common cause but isn't included in the vaccine) oxidase +
- Differences from N. gonorrhoeae: capsule, vaccine, glucose and maltose fermentation
Meningococcal meningitis, meningococcemia (Waterhouse-Friderichsen syndrome- adrenal insufficiency death in 12 hrs)- People who are deficient in C5-9 complements get recurrence of N. meningitidis
capsule, IgA protease, pili; invasion into blood stream --> meninges --> inflammation, LPS (responsible for shock); diffuse vascular damage - Hemorrhagic skin rash (petechiae)
- sudden onset of fever, stiff neck, severe headache, nausea, vomiting, photophobia, confusion, sleepiness
- Thayer-Martin agar, CSF: high protein, low glucose, neutrophils
- Rx: vancomycin + cefotaxime
- Prevention : MPSV4; MCV4
-
Haemophilus influenzae type-b
adults
- Sudden onset, fever, stiff neck, severe headache
- N/V, photophobia, confusion, sleepiness
- CSF: high protien, low glucose, neutrophils
-
Listeria monocytogenes
pregnant women, neonates, immunocompromised patients
- small gram + rods, growth at 1 C to 45 C (can grow in cold food), motile at 25 C-actin jet motility in cells, facultative intracellular pathogen, cell to cell spread
- ingestion of contaminated food, transplacentally or during delivery
- found in unpasteurized milk products, soft cheeses, deli meats, hotdogs
- When pregnant women get infected they become septic --> bacteria crosses the placenta and lead to granulomatosis infantisepticum (sepsis w/ high mortality; disseminated granulomas w/ central necrosis).
- meningitis w/ septicemia occurs after birth.
- Culure on bood agar, CSF: high protein, low glucose, neutrophils
- Rx: Ampicillin + gentamicin
-
Cryptococcus neoformans, coccidioides immitis
immunocompromised patients
- Cryptococcus #1 cause of meningitis in AIDS patients
- subacute
to chronic meningitis - slow onset of headache, visual disturbances, abnormal mental status, seizure
- CSF: high protein, low glucose, lymphocytes
- Amphotericin
-
Nagleria fowleri
immunocompetant persons
- free-living warm fresh water amoebae
- meningoencephalitis enter body via olfactory neuroepithelium
- trophozoite and flagellated forms --> purulent, hemorrhagic inflammatory
- Rapid onset, severe headache, fever nausea, altered sense of smell. Progresses rapidly, death in few days
- CSF: wet mount (motile trophozoites), blood, neutrophils, high protein, low glucose
- Rx: Amphotericin B (rarely successful)
-
Acanthamoeba spp
- Opportunistic free living amoebae
- Granulomatousamebicencephalitis (GAE)
- free-living amebae in contaminated contact lens solution (airborne cysts)
- enter body by lower resp tract, ulcerated or broken skin
- Headaches, altered mental status
- Keratitis
- cysts and trophozoites in tissue
-
Toxoplasma gondii
- intracellular protozoa
- cats= definitive host (oocyst from fecal contamination), ingestion of uncooked meat (pork) w/ cyst, transplacental, blood and organ transplant
- oocyst --> trophozoites --> invade macrophages --> spread to all organ systems and form cyst
- selflimited flu-like illness in immunocompetent host, toxoplasmic encephalitis in immunocompromised host (ring-enhancing lesions), maternal infection causes still birth, neurologic problems (hydrocephaly), asymp child can develop blindness later in life (teen years)
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