Summary of characteristics of bacteria-table

Bacteria Morphology Culture
characteristic
s
Biochemical
reactions
Antigenic
structure
Toxins
Pathogenesis/spectr
um of disease
Other if only
mentioned in
the syllabus
Mycoplasma
Gram negative
(before they
name is PPLO)
Respiratory
infection
Shape: granules and
filaments
Size: 100-1000 nm
Smallest free living
microbe
-Non motile
-Non-sporulating
-Reproduce by binary
fission
O 2
requirement:
Aerobes and
facultative
anaerobes
Colonies show
fried egg
appearance
Have bulbous
enlargement
with a different
tip
___ ___ -Pneumonia
(M.Pneumoniae)
Fever, headache,
hemolytic anemia
-Genital infection
M.hominis /
U.urealyticum
By sexual contact
-causes severe
infection in HIV
patients
Urinary tract
infections
E.Coli
Gram
negative
bacterium
Pilli
non mucoid
colonies
Shape: straight, rodshaped
bacteria
Size: 1 to 3 Microns x
0.4 to 0.7 Microns
Arrangement: singly
or in pairs
-Non-sporing
-Some strains
capsulated
-motile
T: 10 C to 40 C
Optimum: 37 C
Growth on
ordinary media
Growth on
MacConkey
media
Positive for
indole and
methyl red
Negative for VP
and citrate
Surface
antigens:
Lipopolysaccha
ride
Toxins:
-Hemolysins
-Enterotoxins
heat labile (LT)
heat stable(ST)
Verotoxin (VT)
Hemolysis
and
enterotoxi
ns
-heat
labile
toxin (LT)
-heat
stable
toxin (ST)
-verotoxin
(VT)
Urinary tract infection
Diarrhea
Pyogenic infection
Septicemia