1. Vibrio

2. Characteristics
Gram-negative, highly motile curved rods, polar flagella
Oxidase-positive
Facultative anaerobic
Tolerant to alkali but not to acid

3. Pathogens of humans
V. cholerae
V. parahaemolyticus

4. Vibrio cholerae

5. Biological characteristics
Structure and shape
Gram-negative curved rods
a single, polar flagellum
Culture
in the absence of salt
at a high pH ( )
TCBS
(thiosulfate-citrate-bile-sucrose)

6. Biological characteristics
Antigenic structure and classification
H antigen: non-specific
O antigen: 155 serogroups
V. Cholerae serogroups O1
V. Cholerae serogroups O139
V. Cholerae serogroups non-O1/non-O139

7. Biological characteristics
Antigenic strcture and classification
2 biotypes (O1): classic biotype
El Tor biotype
3 serotypes (O1): Ogawa（AB）
Inaba（AC）
Hikojima（ABC）

8. History
Epidemic: a disease occurring in an unusually high number of individuals in a population at the same time.
Pandemic: a worldwide epidemic.
Endemic: a disease that always presents in low members in a particular community
Sporadic: a disease that occurs occasionally, usually affecting one person.
7 pandemics (since 1817)
the former 6 pandemics → classical strains (O1)
the latter 1 pandemic → El Tor strains (O1): began in 1961 in Asia.
a recent epidemic (in 1992 in India) → V. Cholerae O139→ cholera-like symptoms.

9. Pathogenicity Virulence factors Vibrio cholerae enterotoxin Flagellum
pili（toxin-coregulated pilus A, tcpA）
other toxic factors: hlyA, hap
capsule: O139

10. Mode of enterotoxin a protein composed of A and B subunits.
B subunits (binding sites) → binding to receptors of epithelial cells
A subunit (toxic site) → activating adenyl cyclase ↓
ATP → cAMP
changing ion transport mechanisms
extensive secretion of fluids and electrolytes
ie. Na+, Cl-, K+, HCO3-
severe vomiting and diarrhea

12. Pathogenicity Disease: Cholera human is the only host
Source of infection : (O1,O139)
ingestion of the contaminated food and water
1010 bacteria → mouth → stomach → small intestine → enterotoxin

14. Pathogenicity Incubation period: 2-3 days. Manifestation:
severe vomiting, rice-water diarrhea, and dehydration.
Death rate: renal failure, metabolic acidosis, shock.
non-O1 strains: symptoms similar to those of O1 strains, but less severe; often sporadic not pandemic or epidemic.

15. Immunity HI Permanent SIgA antibodies vibriocidal antibodies
antitoxin antibodies
Permanent

16. Control Prevention Treatment improvement of sanitation
vaccine: limited or no effective
Treatment
water and electrolyte replacement
antimicrobial agents

17. V.parahaemolyticus

18. Characteristics a marine vibrio
culture - grow best under high salt concentration condition.

19. Pathogenicity Virulence factor hemolysins
hemolyze the human and rabbit erythrocytes
-kanagawa test 神奈川现象:
differentiates pathogenic strains from non-pathogenic strains

20. Pathogenicity Disease Gastroenteritis (food poisoning) Transmission
ingestion of potential contaminated seafood
Manifestations
watery diarrhea, abdominal cramps,
nausea, and vomiting.

21. Treatment in mild infections self-limited disease in severe infections
antibiotics, fluid and electrolytes replacement