Summary of characteristics of bacteria-table

Bacteria Morphology Culture
characteristics
Gastrointestin
al infections
Vibrio-
Cholerae
(gram
negative)
Colonies are
colorless
Shape: Curved
or comma
Shaped
Size:
1.5microns x
0.2 to 0.4
microns
*Motile
*Non-sporing
*Non
capsulated
T: 16 c to 40c
PH:6.4 to 9.6
O 2: aerobic
Culture:
*solid media
*MacConkey
Biochemical
reactions
*Ferment
sugar and
produce acid
*Positive
reaction
towards indole
and nitrate
Antigenic
structure
______
Toxins
Exotoxin
Enterotoxin
Pathogenesis/spectr
um of disease
Causes diarrhea
*Hypersecretion of
water and electrolytes
*Inhibition of
reabsorption of sodium
chloride resulting
diarrhea
Other if only
mentioned in
the syllabus
Gastrointestin
al infections
Shigella
(Gram
negative)
Shape: rodshape
Size:
0.5micronsx
1.3microns
*Non-motile
*Non-sporing
*Noncapsulated
T: 37 C
Ph:7.4
O 2: aerobes and
facultative
anaerobic
Culture:
*Deoxycholate
citrate agar(DCA)
*Sodium selenite
borth
*MR positive
and reduce
glucose
*Somatic (O)
antigens and
some strains
produce
endotoxin
Endotoxin
Bacillary
Dysentery
*Infection occur by
ingestion
_Infection of intestine