Vibrio are comma-shaped, gram-negative, noncapsulated, and strictly aerobic bacteria. They have polar flagella that allow for darting motility. Vibrio's natural habitat is coastal seawater where they exist in close association with plankton. They can survive in ice-cold water for 2-4 weeks but are killed by heating to 56°C or boiling. Chlorination is effective at killing Vibrio. The most common pathogenic species is V. cholerae which causes cholera in humans. Cholera infection occurs through ingestion of contaminated food or water and is characterized by painless, watery diarrhea and rice water stools. Treatment involves oral rehydration therapy

1. Vibrio

2. Vibrio
• Coma shaped
• Gram negative
• Noncapsulated
• Strict aerobes

3. Vibrio has a polar flagella darting motility

8. Natural habitat of vibrio
• a/w coastal sea water in close
relation with plankton
• Survives in a nonviable non cultivable
form

9. • Survive in ice cold water for 2- 4 weeks
• Killed with in 30 by heating @ 56 * C or with in a few seconds of
boiling
• Chlorination is effective against cholera
• Man is the only reservoir
• Infection is acquired through fecally contaminated food or water

10. • Much hardier than classical vibrios capable of surviving in
environment much longer
• Severity of illness is much less with a large proportion of mild &
asymptomatic infection
• Low mortality & high carrier rate
• Secondary attack is less

11. • Requires 0.5 – 1 % NaCl is required for growth
• All are halophilic except V.cholerae, V.mimicus
• Grow better in alkaline media
• Optm temperature is 37 * C
• Not nutritionally fastidious
• susceptible to heat but resist high alkalinity

12. McConkeys agar
• Initially colurless Pink coloured colonies (later)

13. In McConkey agar initial zone of greening
followed by complete hemodigestion

14. Cholera shows cholera red reaction
• V. cholerae shows positive cholera red reaction by producing a
reddish pink color in the peptone water due to formation of nitroso
indole.
• The two properties of formation of indole and reduction of nitrates
to nitrites form the basis of cholera red reaction. This reaction is
tested by adding a few drops of concentrated sulfuric acid to a 24-
hour peptone water culture at 37°C

15. • Catalase positive
• Oxidase positive

16. • String test+ve with Na
deoxycholate

18. Predisposing pathogenic factors
• To overcome acidic environment of stomach
• Large inoculum size
• Achlorhydria
• To cross protective mucus layer
• Chemotaxis
• Mucinase
• Protease
• Toxin co regulated pilus
• Cholera toxin

19. • Cholera is non invasive
• TCP helps in attachment
• Ds due to cholera toxin
• Toxin is phage coded
(filamentous phage )

22. • IP 24 – 48 hrs
• Painless watery diarrhea
• Sweet inoffensive odour
• Rice water stools
•

23. • Mild neutrophilic Leucocytosis
• Elevated levels of blood urea nitrogen and creatinine
• Reduced bicarbonate level (<15 mmol/L);
• Elevated anion gap
• Low Arterial pH

24. Rx
• Main rx
• Replenish lost body fluids & electrolytes
• Single dose of doxycycline
• Furazolidone is the DOC in pregnant women
• Rapid & adequate replacement of fluid electrolytes & bases
• Chemoprophylaxis
• DOC is tetracycline
• Only for close contact
• No mass chemoprophylaxis

25. Vaccines
• Parenteral vaccine:
• – Contains- Classical (6000 million of Ogawa & Inaba)
• – Effcacy- 50%, lasts for 3-6 months, effcacy is better in adult > children
• – No cross protection b/t ogawa & inaba
• – Cross protection b/t ElTor & Classical
• Oral vaccine-
• – WC/rBS (whole cell recombinant subunit - 2 dose, 50-60% protection for 3
year,
• – CVD 103-HgR- 1dose, 80% protection

27. 3 doses for children 2- 6 yr old

28. HALOPHILIC VIBRIO

29. HALOPHILIC VIBRIO
• If > 1 % NaCl  halophilic
• ↑NaCl tolerance-
• V. parahemolyticus (7%),
• V. alginolyticus (10%),
• V. vulnifcus (8%)

30. V. parahemolyticus:
• Food poisoning following consumption of sea foods
• Shows kanagawa phenomenon on wagatsuma agar
• Peritrichous flagella,
• green colony on TCBS (sucrose non fermenter)

31. Shows kanagawa phenomenon on wagatsuma
agar
Strains from humans are
haemolytic Strains from environment are non haemolytic

32. V. vulnifcus:
• Lactose fermenter
• Causes-Wound infection, secondary cellulitis, gastroenteritis (sea
water exposure)
• Also causes- Sepsis (in low immunity and underlying liver disease like
cirrhosis or hemochromatosis) (Shellfsh)

33. V. alginolyticus:
• Most salt-tolerant ( >10%)
• Occasionally causes eye(conjunctivitis), ear (otitis media), and wound
infections
• Also causes Sepsis – in patients with burned, other
immunosuppressed condition Seawater
• Tetracycline- DOC

34. • V.metschnikovii- Oxidase negative