Bordetella pertussis Flashcards
Characteristics of B. pertussis?
- extremely small
- Gram (-)
- Coccobacilli
- Obligate aerobes
- non motile
What is the medium required for isolation from direct cough plates or nasopharyngeal cultures for B. pertussis
Regan Lowe Media (charcoal added)
What is the major manifestation of B. pertussis?
Whooping Cough
What is the mechanism of action of Pertussis toxin (PXT)?
Over activates adenylate cyclase by disabling Gi. and leads to excessive mucous production
What is the manifestation of Whooping cough?
Child coughs on expiration and “whoops” on inspiration
B. pertussis can cause the following clinical diseases?
- Subconjunctival hemorrhage
- Facial & truncal petechiae
- Hernias
What stage of B. pertussis lasts 2-4 weeks and has repetitive coughs with whoops and vomiting?
Paroxysmal stage
What are the VF’s B. pertussis uses for attachment?
- FHA (fhaB)
- Fimbriae (fimD)
- Pertactin
What are the toxins B. pertussis releases?
- Tracheal CytoToxin (TCT)
- Pertussis Toxin (PTX)
- Adenylate cyclase toxin (ACT)
how does tracheal cytotoxin work?
its an exotoxin that inhibits DNA synthesis in epithelial cells
How does Adenylate cyclase toxin (ACT) work?
Binds to Adenylate cyclase, leads to unresponsive IL-8 receptor and C5a receptor and leads to lymphocytosis
What kind of colonies does B. pertussis produce on a blood agar?
Small, shiny, mercury like colonies
What are the 3 stages of B. pertussis?
- Catarrhal stage
- Paroxysmal stage
- Convalescent stage
What vaccine can you use to prevent B. pertussis?
DTaP
(diphtheria, tetanus, Pertussis)
- includes strains of pertactin, FHA and fimbriae
What is the treatment of choice for Bordetella?
Macrolides OR AUGMENTIN (amoxicillin + clavulanate)
