Vibrio cholerae is a serious bacterial disease primarily causing severe diarrhea and dehydration, often spread through contaminated water. While modern sanitation has largely eliminated cholera in many countries, it remains a significant issue in regions affected by war, poverty, and natural disasters. Symptoms include watery diarrhea and vomiting, with treatment focusing on fluid replacement and antibiotics.

1. Vibrio cholerae
T.SATHYA,
II MSC MICROBIOLOGY.

3. Vibrio cholera
Cholera is a serious bacterial disease that usually
causes severe diarrhea and dehydration. The disease is
typically spread through contaminated water.
Modern sewage and water treatment have effectively
eliminated cholera in most countries. It’s still a problem in
countries like Asia, America and Africa. Mostly in India.
Countries affected by war, poverty, and natural disasters
have the greatest risk for a cholera outbreak.

4. TAXONOMY:
 class : Gamma Proteobacteria
 Order: Vibrionales
 Family: Vibrionaceae
 Genus: Vibrio
 Species: v.cholerae, v.parahaemolyticus,
v. vulnificus, v. alginolyticus

5. MORPHOLOGY:
 Gram negative, actively motile, short, rigid curved bacilli
 Resembling letter “V”
 about 34 genus
 most common in water
 1.5µ X 0.2 -0.4 µ in size
 polar flagellum , strongly aerobic
 Smear – fish in stream appearance ( koch)

6. Culture media:

10. Biochemical test:

11. Modes of transmission:

12. Pathogenesis:
Source: Ingestion of contaminated water, food,
fruits and vegetables etc.,
Incubation periods: 1-5 days
Symptoms: Watery diarrhoea, vomiting, thirst,
dehydration, muscle cramps
Complications: muscular pain, renal failure,
pulmonary edema, cardiac arrhythrnias

14. Diagnosis:
Specimen: stool sample, water sample(envt)
Microscopy: a) Hanging drop : +ve
b) Gram stain :-ve
Culture: Mac conkey Agar :colourless to light pink
TCBS : yellow colonies
Serology: serological tests are no diagnostic value

15. String Test:
Used to identify V.cholerae colonies.
Loopful of vibrio growth
Drop of 0.5% Sodium Deoxycholate solution
Substance become MUCOID

17. Cholera red reaction:
• Best identification test for V. Cholerae.
• Drops of Conc. Sulphuric acid + peptone culture
allow for 24 hours
RED colour

19. Treatment:
• Adequate replacement of fluids and electrolytes.
• Oral tetracycline reduces the period of vibrio
excreation.

20. Prevention:
• Drink and use bottled water
• Frequent washing
• Sanitary environment
• Defecate in water
• Cook food thoroughly