Tetanus and botulism are acute diseases caused by Clostridium tetani and Clostridium botulinum respectively. C. tetani produces a neurotoxin called tetanospasmin which causes muscle rigidity and spasms. It enters through wounds in the skin. C. botulinum produces a toxin that blocks acetylcholine release at the neuromuscular junction, causing paralysis. The bacteria forms spores that allow it to survive in soils and foods. Proper wound care and vaccination can prevent tetanus, while safe food handling prevents botulism.

1. TETANUS AND BOTULISM
Sijo.A
M.Sc.Microbiology
21811422

2. TETANUS
 Tetanus is a acute disease manifested by skeletal muscle
spasm and autonomic nervous system disturbance.
 It is caused by Clostridium tetani.
Morphology
 It is a gram positive rod shaped bacterium.
 They are obligatory anaerobic.
 They produces terminal spore with “drum stick appearance”.
 They commonly found in soils, hospital environment,
intestine of man and animals.

4. PATHOGENICITY & VIRULENCE FACTORS
Toxins
1. Tetanolysin (Haemolysin)
 Heat labile, oxygen labile
 It is antigenically related to C.perfringens, S.pyogens,
S.pneumoniae.
 No role in the pathogenesis of tetanus.

5. 2. Tetanospasmin
 It is a neurotoxin.
 It is oxygen stable but heat labile.
 It is a polypeptide chain.
 It is made up of 2 chains : H chain (MW 93,000) and L chain
(MW 52,000) joined by disulphide bond.
 It is plasmid coded.
 It becomes toxin by treating with formaldehyde.
 It is neutralised by antitoxin.
 MLD is different in different species.
 MLD for human being is 130 nanogram.

6. MECHANISM OF ACTION
Contamination of wound by C.tetani spores
Germination in favourable conditions
Toxin production & its absorption locally by nerve endings &
reach to the CNS by peripheral nerve
Toxin binds to the ganglosides of grey matter & acts
presynaptically by inhibiting the release of GABA & Glycine
Resulting uncontrolled spread of impulses
Tonic muscle rigidity and spasm

7. MODE OF TRANSMISSION
Superficial abrasions Punctured wounds
Road traffic accidents

8. Surgery done without proper asepsis

9. Neonatal tetanus

10. LABORATORY DIAGNOSIS
1. Direct Microsopy
 Gram positive rod shaped bacteria with terminal spore like
drum like appearance.

11. 2.Cultural characteristics
 In moist media, they show swarming growth and it
interferes the isolation of pure culture.

12. 3. Gelatin stab culture – fir tree growth with slow liquefaction
4. Blood Agar
- alpha hemolysis followed by beta
hemolysis due to the production of
tetanolysin
5. Robertson cooked meat broth
- turbidity & gas formation

13. PROPHYLAXIS & TREATMENT
 Tetanus is a preventable disease.
 General measures : keeping the wound cleean
 Surgery : removal of necrotic tissue, blood clots & foreign
material to prevent the development of anaerobic
environment.
 Systemic antibiotics : Penicillin (Pn) & Metronidazole.
 Local antibiotics : bacitracin & neomycin.

14. IMMUNOPROPHYLAXIS
 Active immunisation
1. plain toxoid
 Made by incubating the toxin with
formalin
2. Adsorbed toxoid
 Toxoid absorbed on a Al(OH) or P.
 Given either alone or in combination with
triple vaccine (DPT).
 Given by intramuscular and subcutaneous
route.
 3 doses are given : 6th week,10th week and
14th week of age.
 “Booster Dose” is given after 10 years.
 Frequent injection causes hypersensitivity.

15. IMMUNOPROPHYLAXIS
Passive immunisation
 It is an emergency procedure.
 It is recommended only in non-
immune person and only once.
i) Antitetanus serum
 1500 IU dose.
 Disadvantage : immune
elimination and
hypersensitivity
ii) Antitetanus immunoglobulin
 250 IU dose
 It has longer half.

16. Sijo.A
M.Sc.Microbiology
21811422

17. BOTULISM
 It’s a food born intoxication caused
by the ingestion of toxin produced
by Clostridium botulinum.
 Found in canned foods.
Morphology
 It’s a gram positive rod shaped
bacterium.
 They are obligatory anaerobic.
 They produces subterminal, oval
and bulging endospores.
 Mainly found in soil.

18. PATHOGENICITY & VIRULENCE FACTORS
1. Endospores
 Heat and radiation resistant
 They survive several hours (100-120 degree)
 It act as a source of infection.
 They germinate & produces botulinum toxin during their
vegetative growth.
2. Toxin
 Exotoxin
 It is not released during the life of the organism.
 It is produced intracellularly & appears in the medium only
when cell death and autolysis.
 It’s a neurotoxin.
 It consists of 19 amino acids with a MW of 1,50,000 daltons.
 Lethal dose for human being is 1-2 ug.

19. TOXIN EFFECTS
 Toxin absorbed from gut & blocks acetyl choline release at
neuromuscular junction.
 It breaks synaptic vesicle membrane protein – synaptobrevin
 Failure of muscle contraction

20. FACTORS AFFECTING TOXIN PRODUCTION
 Glucose / maltose increases toxin production.
 They grow in low acid food (low pH).
 In united states, toxin production also reported in high acid
food. It occurs due to the presence of other microorganisms
that will change the pH and promotes the growth of
C.botulinum.
Incubation period
 12-34 hrs.
 Death occur due to respiratory failure.
 It occur after 1-7 days after onset..

21. LABORATORY DIAGNOSIS
1. C.botulinum is isolated using EYA, blood agar & three
bottles of CMB
2. Inoculation of mice with patients blood serum, stools and
vomitus to prove toxigenicity.
3. Haemagglutination is also done

22. INFANT BOTULISM
 It was first reported in 1976 (US)
 It occurs in 3 weeks to 9 months in age.
 Both sexes are affected equally.
 It occurs due to the ingestion of C.botulinum spores present in
honey.
 Baby excrete toxins & spores in the faeces.
 Management consists of supportive care & assisted feeding.

23. PREVENTION
1. Approval of heat processed canned food.
2. Rejection of swollen cannes
3. Refusal to taste a droughtful food
4. Avoidance of food that have been cooked and reheated.
5. Proper sanitation.
6. Cleaned fish should be placed in frozen food.

25. THANK YOU….