Download VIBRIO CHOLERAE

Awang Ismawi Bin Awang Ismail
Wan Muhammad Hakimi Bin Wan Zakaria
 Gram
negative bacteria
 Three members pathogenic to human, other
species are pathogenic for animal and insects
 Lead a commensal existance in numerous
hosts or occur as saprophytes, particularly in
water
 Found
in fresh and brackish (slighly salt)
water, shellfish and other seafood
 Man is the major reservoir for V.cholerae
 Factor of transmission – inadequate
sanitation, lack of person and food hygiene,
use a polluted water to prepare food,
inadequate cooked shellfish etc
 Curved
rods with rounded ends
 3 x 0.5µm
 Gram negative – pink stained
 Actively motile with single polar flagellum.
To- and fro- movement (dark-field
micsroscopy)
 Non-capsulated, Non-sporing
 Some strain is lateral flagellum
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Produce enterotoxin (exotoxin) that activates
enzyme adenylcyclase
Causing watery diarrhoea producing ‘rice
water’ stool containing vibrios, epithelial
cells and mucus
Adherence factor – motility and extracellular
enzymes such as proteases
Acute cholera – rapid loss of fluid and
electrolytes in stool, vomit leads to muscular
cramps and severe dehydration (fatal),
acidosis, blood urea increase, urine increase
in albumin
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Aerobic
Wide temperature. Optimum 37oC
Grow in ordinary media but sensitive to acid pH
(alkaline; 8.2)
2-3 mm in size after 18 – 24 hr incubation in
optimum temp.
Low convex with an entire edge, whitish and
translucent
Older colonies develop a light ochre tinta tube of
peptone water with a flake of mucus from stool and
incubating for only 6 – 8 hrs
 Ferment
glucose, sucrose, mannitol and
maltose without gas production
 Does not utilise lactose or dulcitol
 Positive in indole and nitrites test
 Non-hemolytic in sheep blood agar (Greig
test)
 Can be tested in H2SO4