Download Closteridium

Lab 17
Msc. Shaimaa obead
Clostridium
Division: Firmicutes
Class: Clostridia
Order: Clostridiales
Family: Clostridiaceae
Genus: Clostridium
Species: C. tetani
C. botulinum
C. perfringens
Clostridia are spore-forming, Gram-positive, anaerobes. They are known
to produce a variety of toxins, some of which are fatal.
There are three species of clostridia that cause widely recognized and
often-deadly diseases. Clostridium tetani is the etiological agent of
tetanus, Clostridium botulinum is the etiological agent of botulism, and
Clostridium perfringens is one of the etiological agents of gas gangrene.
C. tetani:
C. tetani the causative organism of tetanus. Its produces terminal spores,
giving it the appearance of drumsticks or tennis rackets. This species is
motile and produces a single antigenic type of exotoxin. Spore wide
spread in soil and animal feces. Tetanus Toxin, tetanospasmin, causes
tetanus: unopposed muscle spasm, contraction due to interference of toxin
with neurotransmitters. Tetanus (sometimes called lockjaw) is caused by
the toxin (poison) of a bacterium. Tetanus: A disease caused by chemicals
which are produced by a bacterium (Clostridium tetani) and are toxic to
1
the nerves. The infection usually occurs when the bacteria enter the body
through a deep wound - these bacteria are anaerobic and hence don't need
oxygen to survive
C. botulinum:
C. botulinum produces oval subterminal spores and is motile. This
organism producing a toxin in food/wound that causes botulism.
C. perfringens:
C. perfringens produces large rectangular spores and is nonmotile.formerly called C. welchii, causes a wide range of symptoms, from
food poisoning to gas gangrene. Also responsible for enterotoxemia (also
known as "pulpy kidney disease") in sheep and goats and other animals
Gas gangrene
Diagnosis:
Members of the genus Clostridium can be differentiated from other
bacteria by laboratory techniques including enzymatic digestion on eggyolk agar plates.
Diagnosis of C. perfringens:
 Egg yolk agar: opacity appears around the colony because C.
perfringens produce lecithinase.
 Litmus milk agar: after incubation the stormy fermentation will
appear because fermentation of glucose and digestion of casein.

Naglers reaction: plate contain egg yolk agar with human serum
divided in 2 parts. In one part adding 3 dope of antiserum and leave
to dry then culturing each part with bacteria after incubation at 37
under anaerobic condition the part without antiserum show opacity
around the colony while the part with antiserum will not.
2
 Culture: Anaerobically at 37C On Robertson's cooked meat
medium → blackening of meat will observed with the production
of H2S and NH3
Difference characteristic between Clostridium spp.:
Clostridium sp.
Haemolysis
Motility
Terminal spore
C. tetani
+
+
+
C. perfringens
+
_
_
C. botulinum
+
+
_
Biochemical test:
Clostridium sp.
Egg yolk agar
Digestion of fermentation
casein
G
L
S
M
lecithinase lipase
C. tetani
_
_
_
_
_
_
_
C. perfringens
+
_
+
+
_
_
+
C. botulinum
_
+
+
+
+
+
+
G=glucose L=lactose
3
S=sucrose
M=maltose