Bordetella pertussis

One-Sentence Definition

Bordetella pertussis is a fastidious Gram-negative coccobacillus that causes whooping cough (pertussis) via adhesins and toxins, prevented primarily by vaccination but still causing outbreaks in incompletely immune populations.

Taxonomy & Morphology

  • Alcaligenaceae; small coccobacilli; strict human pathogen
  • Related: B. parapertussis, B. holmesii — pertussis-like illness
  • Fastidious: Regan-Lowe / Bordet-Gengou media historically; now NAAT-first

Virulence Highlights

  • Pertussis toxin (PT) — ADP-ribosylating AB toxin; systemic effects
  • Filamentous hemagglutinin, pertactin, fimbriae — adhesion
  • Adenylate cyclase toxin, tracheal cytotoxin — local airway damage
  • Antigenic change (e.g., pertactin-deficient isolates) under vaccine pressure

Clinical Syndromes

  • Catarrhal → paroxysmal cough ± inspiratory whoop / post-tussive emesis
  • Infants: apnea, severe disease, death risk — partial immunization gap
  • Adolescents/adults: prolonged cough, often underdiagnosed; reservoirs for infants

Diagnosis

  • PCR / NAAT on nasopharyngeal specimen — preferred
  • Culture difficult, sensitive mainly early; serology for late presentation in some settings
  • Notify public health for contact management

Treatment Notes (conceptual)

  • Macrolides (azithromycin) — early therapy reduces transmission; limited effect once paroxysmal stage established
  • Post-exposure prophylaxis for high-risk contacts per guidelines
  • Supportive care for infants; hospitalization criteria

AMR

  • Macrolide resistance uncommon in many regions but reported — monitor if failure
  • Not an MDR hospital ESKAPE problem; prevention is vaccine + IPC in outbreaks

Genomics & Computational Notes

Active Recall

  1. Which toxin is unique/central to classic pertussis systemic biology?
  2. Why vaccinate adults/adolescents around newborns (cocooning / pregnancy doses)?
  3. Preferred diagnostic method in routine practice?