Vibrio

1
Vibrio

• Chapter 32

2
Vibrio

• Introduction
• Gram negative curved rods (bacilli)
• Found primarily in water
• Cause gastrointestinal disease

3
Vibrio

• Physiology and structure
• Best known genus V. cholerae
• Causes cholera
• Caused by two antigens O1 and O139
• Produce cholera toxin

4
Vibrio

• Pathogenesis and Immunity
• Genes
• ctxA and B cholera toxin
• tcp toxin coregulated pilin
• acf accessory colonization factor
• hap hemagglutination-protease factor
• Major virulence factor
• Cholera toxin
• Complex A-B toxin
• Adherence
• Able to adhere by pili coded by tcp and acf genes

5
Vibrio cholerae

• Pathogenesis and Immunity
• Mechanism of action of cholera toxin (Fig 32-1)
• Binding via B subunit
• Entry of A subunit
• Activates adenyl cyclase
• Accumulation cAMP
• Release
• Na, Cl-, K, HCO3, and water into intestinal
  lumen

6
Vibrio

• Epidemiology
• Found in esturaine and marine environments
• Ability to survive and replicate in contaminated
  waters
• Found in shellfish
• Spread by contaminated water and food
• Usually seen in communities with poor sanitation

7
Vibrio cholerae

• Clinical Syndromes
• Severe, fatal diarrhea
• 2 3 days onset after ingestion

8
Vibrio cholerae

• Treatment
• Electrolyte replacement