Bordetella & Neisseria Flashcards
What is the clinical presentation of Whooping Cough
- cold w/o fever
- coughing with a whoop (deep breath)
- Difficulty breathing
- emesis for 2-3 weeks
What bug are we thinking with Forceful cough and blood vessel rupture in eyes of child?
Bordetella pertussis
Who is at most risk for death by pertussis?
-Babies who are not vaccinated at that age
What lab technique is used to diagnose Bordetella pertussis?
PCR
What is the medium of choice for growing bordetella?
Regan Lowe agar = charcoal agar w/ 10% horse blood (grows slowly)
How does B. pertussis cause disease?
- Bacteria are inhaled and colonize ciliated epithelium
- injects exotoxin
- Tracheal cytotoxin kills ciliated epithelium
What are the exotoxins produced by B. pertussis?
-Pertussis Toxin (PT) = inhibits neutrophil migration
-Adenylate Cyclase Toxin (CyaA) = inhibits phagocytosis
-Tracheal cytotoxin = killes ciliated epithelium
How does Pertussis toxin work?
- A-B exotoxin (like diphtheria)
- Damage to respiratory cells.
- Inhibits migration of lymphocytes and macrophages to areas of infection.
- Causes lymphocytosis.
How does Adenylate Cyclase Toxin produced by bordetella pertussis work?
Enters neutrophils and catalyzes the excessive production of cAMP which intoxicates the cells such that phagocytosis is compromised.
How do we diagnose pertussis?
- Swab from nasopharynx, cultured onto special media (required by CDC)
- PCR is better
What are the microbiological features of Neisseria?
- Gm (-)
- Diplococci
- intracellular
What is the culture media preferred for Neisseria?
-Chocolate agar
(requires Thayer Martin VCN = Vancomycin, Colistin, Nystatin)
What are the virulence factors of neisseria?
- Pili
- Polysaccharide capsule
- LOS (endotoxin)
What diseases are caused by Neisseria meningitidis?
- Sporadic & epidemic meiningitis
- meningococcemia
**Waterhouse-Friderichesen syndrome
-Rare: bacteremia, pneumonia, septic arthritis
How do we diagnose Neisseria meningitidis?
-gram stain of CSF
What neonatal infections are we worried about with Neisseria gonorrhoeae?
- Conjunctivitis (causes blindness)
- soft tissue abscesses
- arthritis
- bacteremia/sepsis
What are the microbiological features of Bordetella pertussis?
- Gm (-)
- rod
What allows Bordetella pertussis to attach to ciliated epithelial cells of the upper respiratory tract?
-Filamentous hemagglutinin (FHA)
=a pili rod that extends from surface to bind ciliated epithelial cells
What does tracheal cytotoxin produced by Bordetella pertussis do?
-kills ciliated epithelial cells
What does DTaP stand for?
- vaccine
- Diphtheria, Tetanus, acellular Pertussis
What is the only Gm (-) pathogenic cocci?
Neisseria (meningitidis & gonorrhoeae)
“Petechial rash & meningitis”
-Neisseria meningitidis
What is the treatment for Bordetella pertussis?
- No antitoxin available
- Early macrolides may limit severity
- New vaccine has purified and inactivated proteins/toxin (only lasts 4-5 years)
Which, caused by Neisseria meningitidis, is more deadly? Meningococcemia with meningitis or meningococcemia without meningitis?
-Meningococcemia without meningitis
