MICROBIOLOGY

• Bordetella organisms are small, aerobic Gram-negative coccobacilli [Fig 1].
• Organisms are fastidious and need special media (such as charcoal blood agar with cephalexin, Regan Lowe or Bordet-Gengou media) for isolation.
• Species:
  
  • B. pertussis: most common etiology of whooping cough and exclusively a human pathogen.
  • B. parapertussis: leads to less severe but similar symptoms.
  • B. bronchiseptica (agent of kennel cough)
    • Occasional human infections. Bacteria may be flagellated.
  • B. holmesii: rarely been implicated in causing human respiratory disease.
    • It has been shown to cause outbreaks similar to B. pertussis
    • May cause sepsis in immunocompromised patients.
  • B. trematum: rarely found in wounds and ear infections.
  • B. hinzii: an uncommon cause of sepsis in immunocompromised hosts.
  • B. avium: pathogen identified only in birds.