T A B L E V I I
Differential microbiological diagnosis within biotypes of C. diphtheriae and C ulcerans
Species
C. diphtheriae
_ _ _ _ _ _ ~
gmeis
C. diphtheriae
nzitis
C . diphtheriae
intermedius
C. ulcerans
type fermentative gravis
type fermentative mitis
Greyish black daisyheaded colonies
with crenated
edges. and radiary
striations
Black, smooth,
convex medium
sized colonies.
Shiny glossy
surface, regular
circular edges
Growth
Haemolvsis
characters
~
Growth characters
on BA
on nutrient
Gluon CTBA plates
plates
broth
cose
___
Haemolysis Clear liquid.
+
Veil on
+
or
surface.
-
Deposit
Haemolysis Uniformly
always
turbid
+
-c
Greyish black
colonies, medium
sized, circular
edges, granular
surface, intermediate position
between mitis and
gravis
Smooth, greyish,
circular, opaque
colonies
No
Slightly
haemolysis
turbid,
+
granular
deposit on
the walls
and at the
bottom
No
Slightly
(a)
haemolysis
turbid with
+
deposit
becomes
clear in a
(b)
few days
+
Carbohydrate fermentations
Malt- Levu- DexGlv- Pathoose
lose trine Starch cogen penicity
~
+ + +
+ -
-
+ + -
+ + +
+ + -
__
+ t o . v t
or
t0.vt o x i
or
t o r
-
tox+
or
-
+ tox+
or
-
+ , positive reaction.
- , negative reaction.
t tox+ or tox- = diphtherial exotoxin present or absent.