Bacteria infx CNS II Flashcards
Who are most affected by GBS meningitis?
Children (neonates)
What is the gram stain and morphology of strep agalactiae Hemolysis result
Gram Positive cocci
BEta hemolysis
What is the CAMP test result for GBS? Resistant or not to bacitracin?
Positive
Resistant
When do most cases of meningitis caused by GBS occur?
within the first week of life (75%)
Where do neonates get the GBS?
Vagnial canal of carrier mother
What percent of women are colonized with GBS? How many times more likely are these women to give birth to children who get GBS meningitis?
10-30%
25 times more likely
What is the virulence factors of GBS?
Polysaccharide Capsule
What is the function of the capsule of GBS?
- Disrupts complement
2. Impedes phagocytosis
What are the increased risk factors for GBS meningitis for neonates? (4)
- prolonged rupture of membranes
- Preterms
- Previous infant with GBS
- Mom has no Antibody
What are the three early (and late) onset diseases caused by GBS in neonates?
Bacteremia
Pneumonia
Meningitis
How do you diagnose GBS infections?
- Recognize clinical sign
2. Identify through lab cultivation
What is the treatment for GBS meningitis?
PCN
How do we prevent GBS meningitis? (2)
Screen all pregnant women to reduce the likelihood
Intrapartum PCN
What is the gram stain and morphology of Haemophilus influenzae type B?
Gram negative rod
How do you grow HiB?
Chocolate agar
What are the virulence factors for HiB?
PRP capsule
What do the nonencapsulated type of Haemophilus cause?
Conjunctivitis
OM
Sinusitis
What are the signs and symptoms of meningitis caused by HiB?
Fever, stiff neck, HA
What is the major neurological sequelae of HiB meningitis?
hearing loss
How do you diagnose HiB meningitis?
Gram stain CSF
Latex agglutination test
How do we prevent HiB meningitis?
Immunization
What does the vaccine against HiB contain?
Conjugated PRP
What does a positive india ink stain indicate?
Cryptococcus neoformans
What is the gram stain and morphology of Clostridium tetani? Aerobic or anaerobic? Spore forming?
Gram positive rod
Anaerobic
Forms spores
What is the toxin that C. Tetani produces? Where does this act?
Tetanospasmin–acts in the interneurons to prevent inhibition of inhibitory neurotransmittors
Where are spores for C. tetani found?
Soil, feces of animals
Drumstick morphology = ?
Clostridium Tetani
What is the cause of neonatal tetanus?
Umbilical stump contamination
What type of toxin is tetanospasmin? What symptoms does it cause?
A-B toxin
Causes spastic paralysis by binding inter neurons
What is the type of paralysis seen in botulinum poisoning?
Flacid
What are the signs/symptoms of C.Tetani?
Lock jaw
Neck stiffness
How long does tetanus poisoning last for?
Weeks
How do you diagnose Tetanus?
Clinical presentation
Why is it hard to detect tetanospasmin or the bacteria? (2)
Difficult to detect toxin d/t bound to neurons
Hard to grow (anaerobic)
What is the treatment for active tetanus intoxication?
Passive and active immunization
IVIG + vaccination
What is the goal of treatment for tetanus poisoning?
remove any unbound toxin
What is the gram stain and morph of clostridium botulinum? Aerobic/anaerobic? Spores?
Gram positive rod,
Anaerobic
Spore-forming
What is the toxin produced by C.Botulinum? How is it delivered to us?
Botulinum toxin
Ingested
C.Botulinum is an infection, true or false
False–intoxication
What is the cause of floppy baby syndrome?
C. Botulinum intoxication
What is the MOA of C.Botulinum toxin?
A-B toxin Blocking of SNAREs to release ACh
What is the gram stain and morphology of listeria monocytogenes? Motile?
Gram positive rod
Motile
What are the vectors of listeria?
Ready to eat meats
What CNS problem can listeria cause?
5-10% of meningitis
Why is listeria found in meats?
Like salts, cold
Can TB cause meningitis? How does it present?
Yep, but slowly because it’s a slow growing bacteria
How does S.Aureus cause meningitis (what disease does it follow)?
Follows bacteremia or traumatic inoculation and brain abscess
Does Clostridium Tetani cause an infection or an intoxication?
Intoxication
Baby + honey = ?
Botulinum poisoning
Can Listeria be transmitted to fetus?
yes
