Bordetella
PERTUSSIS/ WHOOPING COUGH
- Usually disease of children
- Has 3 symptomatic stages
- Catarrhal – mild cold; runny nose
- Paroxysmal – vomiting and with “whooping”
- Convalescent
| Lab Diagnosis | |
| Culture | Most sensitive early in the illness Traditional diagnostic standard for pertussis May become undetectable by culture 2 weeks after start of paroxysms Nasopharyngeal aspirates or nasopharyngeal swab; Calcium alginate or Dacron COTTON SWABS – INHIBITORY THROAT, SPUTUM – UNACCEPTABLE ANTERIOR NOSE – SITES ARE NOT LINED WITH CILIATED EPITHELIUM |
| Cultivation | Regan – Lowe – with charcoal supplemented w/ horse blood Bordet-Gengou – potato fusion base Cephalexin |
| Colony Appearance | small and shiny; resembles mercury droplets; becomes whitish gray w/ age. |
| Characteristics | B. pertussis | B. parapertussis | B. bronchiseptica |
| Catalase | + | + | + |
| Oxidase | + | – | + |
| Motility | – | – | + |
| Nitrate | – | – | + |
| Urease | – | + (24 hrs.) | + (4 hrs.) |
| Growth Regan Lowe agar | 3-6 days | 2-3 days | 1-2 days |
| Blood agar | – | + | + |
| McConkey Agar | + | +\- | + |
VIRULENCE FACTORS OF Bordetella pertussis
- Pertussis toxin – exotoxin; interferes signal transduction
- Adenylate Cyclase toxin – inhibits immune effector cells; induces supraphysiologic conc. of cAMP
- Tracheal toxin – causes ciliostasis; inhibits DNA synthesis; promotes cell death
- Filamentous hemagglutinin
