Clostridium tetani is a gram-positive, rod-shaped bacterium that causes the disease tetanus. It forms spores that allow it to survive in environments without oxygen. The spores can enter the body through wounds and germinate under anaerobic conditions, producing a toxin that travels along the nervous system to the spinal cord. This toxin blocks neurotransmitters and causes painful muscle spasms, starting with the jaw and potentially leading to death if the respiratory muscles are affected. Laboratory diagnosis involves microscopy, culture studies, and biochemical tests to identify the bacterium, as well as animal inoculation experiments. Treatment involves wound cleaning, antibiotics, and vaccines to prevent further cases.

1. RATHEESH R.L
CLOSTRIDIUM TETANI

3. MORPHOLOGY
 Gram positive, motile, Rod shaped, slightly
curved bacilli measuring 2.5 X 0.4-0.5 mu
m, occurring singly or in chains.
 Spores are presenting in the terminal part
and gives a drum stick appearance.

4. CULTURAL CHARACTERISTICS
 They are anaerobic, growing maximum in
the temperature of 37 degree C, at the
pH of 7.4
 They grow well in the ordinary media and
the growth can be improved by adding
serum or blood into this ordinary media.

5. NUTRIENT AGAR MEDIUM
 They produce swarming growth in this
medium
 Colonies formed will be round, grayish-yellow
color, transparent with granular surface.
 The size of colonies will be 2-5 mm in
diameter.

6. BLOOD AGAR MEDIUM
 They produce a zone of alpha hemolysis
around the colonies in the blood agar medium.
 Later it changes to beta hemolysis due to the
presence of haemolysin.( Hemolysins or
haemolysins are lipids and proteins that cause
lysis of red blood cells by destroying their
cell membrane.)

7. COOKED MEAT MEDIUM
 The medium after incubation become
turbid with gas formation.
 The meat is not digested, but turns to
black color during prolonged incubation.

8. LACTOSE EGG YOLK MEDIUM
 No opalescence ( transmission of light
through it) is produced in the medium.

9. PATHOGENICITY
 C. tetani affects humans by causing the disease called
tetanus.
 The spores enter its host through open wounds, lacerations,
or burns where many cells are dead. This provides the
necessary environment for C. tetani to begin to spread to
the human body.
 In the presence of anaerobic conditions (lacking oxygen),
the spores can germinate. This is when the spores produce
toxins that are harmful to the human nervous system.

10.  The toxin tetanospasmin travels through the body via
the nervous system, where its goal is to reach the spinal
cord.
 Here is where the toxin really begins to attack the body.
The toxin interferes with the neurotransmitters and,
thus, blocks messages to the brain.
 This leads to unwanted muscle contractions and spasms,
and in bad cases, individuals can experience severe
seizures.

11.  The clinical pattern of generalized tetanus consists of
severe painful spasms and rigidity of the voluntary
muscles.
 The characteristic symptom of "lockjaw" involves
spasms of the masseter muscle. It is an early symptom
which is followed by progressive rigidity and violent
spasms of the trunk and limb muscles.
 Spasms of the pharyngeal muscles cause difficulty in
swallowing. Death usually results from interference
with the mechanics of respiration.

12.  Earlier the masseter muscle are affected
but as the spasm progresses to extensor
muscles of the body, the body becomes
arched in OPISTHOTONUS POSITION

14. LABORATORY DIAGNOSIS
 Hematological investigation
no significant changes
 Bacteriological investigations
1.microscopy studies
2.culture studies
3.biochemical tests
4.animal inoculation test

15. MICROSCOPY STUDIES
 Smears made from the wound swab,
necrotic material from wound, pus or
tissue from the wound.
 While gram staining it shows gram positive
bacilli with drum stick appearance.

16. CULTURE STUDIES
 When the specimen is inoculated in the
blood agar medium, the organism will
produce large colonies after 1-2 days at
37 degree C of anaerobic incubation.

17. BIOCHEMICAL TESTS
1. Sugar fermentation test: positive
2. Indole test: positive
3. H2S Production test: negative
4. Gelatin liquefication test: positive
5. MR & VP Test(Methyl Red and Voges-
Proskauer Test Protocols): negative

18. ANIMAL INOCULATION TEST
 Two mice are selecting for the study
 One is protected with 1000 units of tetanus
anti-toxin intraperitoneally 1 hr before the
study and other one is unprotected.
 0.2 ml of 2-10 days old cooked meat broth
culture filtrate is injected S/C in the tail of
the rats.

19.  In positive cases the stiffness and spasm
of tail develops in the test animal within
12-24 hrs and which subsequently spread
to the body and death occurs in 1-2 days.
 However in control animal no changes will
occur.

20. TREATMENT
 Surgical methods include removal of dead,
damaged or necrosed tissue, contaminated tissue,
blood clots and foreign bodies from the wound.
 Antibiotics for the treatment includes penicillin
and erythromycin

21. VACCINES
 Active vaccines are TT and DPT
 Passive vaccine is anti-tetanus serum