Bordetella pertussis
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Bacteria - Gram Negative
- Neisseria spp: Overview
- Neisseria gonorrhoeae
- Neisseria meningitidis
- Haemophilus influenzae
- Bordetella pertussis
- Brucella
- Legionella pneumophila
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- Pseudomonas aeruginosa: Disease
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- Campylobacter jejuni
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- Treponema pallidum: Diagnosis
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Bordetella pertussis
- Characteristics
- Gram negative coccobacillus
- Aerobic
- Colonizes mucosal surfaces with high oxygen content (e.g. lungs, airway)
- Virulence factors
- Pertussis toxin (an exotoxin)
- activates adenylate cyclase by inhibiting Gi
- Increased intracellular cAMP leads to increased secretion of sodium, chloride, and water (edema), which impairs phagocytosis, allowing the bacteria to survive
- Similar mechanism to Bacillus anthracis edema factor
- activates adenylate cyclase by inhibiting Gi
- Tracheal cytotoxin
- Kills epithelial cells (cytotoxin) in airways, which impairs mucociliary escalator from clearing respiratory secretions
- Pertussis toxin (an exotoxin)
- Disease
- Infants are especially at risk
- <6 months old – too young to vaccinate
- Unvaccinated children
- 3 stages
- Catarrhal
- low-grade fevers and runny nose (coryza)
- Paroxysmal
- Causes whooping cough
- paroxysms of intense cough followed by inspiratory “whoop” (gasp for air)
- Technically a form of acute bronchitis
- Severe coughing may cause vomiting (posttussive emesis)
- Causes whooping cough
- Convalescent
- Gradual recovery of bronchitis and cough
- Catarrhal
- Infants are especially at risk
- Prevention
- Tdap, DTaP vaccines
- The acellular pertussis vaccine currently available in the U.S. contains purified components of Bordetella pertussis and detoxified pertussis toxin (toxoid)
- Tdap, DTaP vaccines
- Diagnosis
- Bordetella PCR and serology is the gold standard
- Unlikely to be tested, given that this is too obvious
- requires nasopharyngeal secretions on a special swab, as the bacteria will not grow on cotton
- Culture in Bordet-Gengou agar
- Modified Regan-Lowe medium selective for Bordetella
- May be mistaken as viral infection due to lymphocytic infiltrate resulting from immune response
- Bordetella PCR and serology is the gold standard
- Treatment
- Macrolides
- TMP-SMX may be used if allergic to macrolides
- Macrolides