This document provides information on various Clostridium bacteria including C. septicum, C. novyi, C. histolyticum, and C. tetani. It describes their morphological characteristics, toxins produced, diseases caused such as gas gangrene, and laboratory methods for diagnosis. Gas gangrene is defined as a rapidly spreading muscle tissue death caused by clostridial bacteria. Treatment involves surgery to remove damaged tissues, antibiotics such as metronidazole, and immunization to prevent further infection.
2. CLOSTRIDIUM SEPTICUM
Pleomorphic bacillus
Oval, central/subterminal spores
Anaerobic. saccharolytic, abundant gas
Four distinct toxins
Alpha toxin is hemolytic, demonecrotic and lethal
Gas gangrene in humans
3. CLOSTRIDIUM NOVYI
Large, pleomorphic bacillus
Oval, subterminal spores
Strict anaerobe
Type A – causes gas gangrene
Large amounts of edema fluid, little or no observable
gas, high mortality
5. ANAEROBIC WOUND INFECTIONS
Simple wound contamination – no invasion of tissue
Anaerobic cellulitis – invasion of fascial planes,
minimal toxin production, no invasion of muscle
tissue
Anaerobic myositis – gas gangrene, invasion of
muscle tissue, abundant formation of exotoxins
6. GAS GANGRENE
Rapidly spreading, edematous myonecrosis in
association with severe wounds of extensive muscle
mass
Etiology
C. perfringens
C. novyi
C. septicum
C. histolyticum
8. CLINICAL PRESENTATION
Incubation period – 7 hours to 6 weeks
C. perfringens – 10–48 hours
C. septicum – 2–3 days
C. novyi – 5–6 days
Increasing pain, tenderness and edema over the affected
part
Accumulation of gas – crepitus
Untreated – profound toxemia and prostration
9. LABORATORY DIAGNOSIS
Diagnosis on clinical grounds
Laboratory – confirmation of diagnosis and
identification of infecting organism
10. SPECIMEN
Films – edge of affected area, tissue from necrotic
area, exudate from deeper part of wound
Exudate collected from depth of wound – collected
by capillary pipette or swab
Necrotic tissue/muscle fragments
11. MICROSCOPY
C. perfringens – Gram-positive bacilli without spores
C. septicum – boat- or leaf-shaped pleomorphic
bacilli
C. novyi – large bacilli with oval or subterminal
spores
14. TREATMENT AND PROPHYLAXIS
Surgery – most important therapeutic and
prophylactic measure in gas gangrene
Damaged tissue removed extensively and promptly
Hyperbaric oxygen
15. TREATMENT AND PROPHYLAXIS
Antibiotics – metranidazole – IV – before surgery
and repeated every 8 hours
Mixed aerobic and anaerobic infection – combination
– metranidazole with amoxicillin and gentamicin
16. TREATMENT AND PROPHYLAXIS
Passive prophylaxis – anti-gas gangrene serum –
containing
10,000 IU – C. perfringens
10,000 IU – C. novyi
5000 IU – C. septicum
Given IM
17. CLOSTRIDIUM TETANI Hippocrates
1889 – Kitasato – pure forms reproduced disease –
inoculation in animals
Distribution: ubiqutous, soil, intestine of man,
animals, hospital dust, cotton, bandages, plaster of
Paris, catgut, talc
20. CULTURE
Deep agar shake culture – colonies –spherical with
filaments arranged radially
Gelatin stab cultures – fir tree growth
RCM – turbidity with gas formation
Blood agar – α hemolysis, later β hemolysis
21. RESISTANCE
Sensitivity to physical and chemical
Varies – boiling 5–15 minutes, 3 hrs
Iodine 1%
Dry heat 150°C for 1 hr
Resistant to 5% phenol
22. CLASSIFICATION
Ten serological types – I to X
All types produce the same type of toxin which is
neutralised by antitoxin produced against any one
type
23. TOXINS
Two toxins – hemolysin (tetanolysin) and neurotoxin
(tetanospasmin)
Antigenically and pharmacologically distinct
24. TETANOLYSIN
Heat labile
Oxygen labile hemolysin
Produced by C. perfringens, C. novyi and Str.
pyogenes
25. TETANOSPASMIN
Responsible – tetanus
Heat labile – inactivated at 65°C in five minutes
Good antigen, specifically neutralised by antitoxin
Toxoided spontaneously, low concentration of
formaldehyde
28. FAVOURABLE DISEASE CONDITIONS
1. Anaerobic
2. Presence necrotic
3. Other bacteria
4. Lack of drainage
5. Dose and toxigenicity of strain
6. Site and nature of wound
7. Immune status of host
8. Incubation 6–12 days
Mortality rate 80–90 per cent before specific
treatment was available
Tetanus neonatarum and uterine tetanus 70 per cent
35. SEROTYPING
Ten serotypes I–X
VI – Non-flagellate strains
Toxins and pathogenicity
Neuro toxin develops – cultures 2–14 at 35°C
36. TOXIGENICITY TEST
In vitro
Blood agar plates – one half tetanus antitoxin (1500
units)
C. tetani inoculated on each half of plate
Incubated anaerobically – two days
Toxigenic C. tetani – hemolysis around colonies on
half without antitoxin
37. TOXIGENICITY TESTING
In vivo
Control
500–1500 units
Anti toxin 1 hr before
IP
Test
0.1 ml hind limb
Ascending tetanus
44. OAKLEY – “ Rapidly spreading, edematous myonecrosis,
occurring characteristically in association with severe wounds
of extensive muscle massel with that have been contaminated
with pathogenic clostridia particularly with cl.perfringes ”
Clostridium – enters the wound along with implanted foreign
particles
also present on normal skin, perineum & thighs
infection may be endogenous
MAC LENNAN – 3 TYPES
Simple wound
Anaerobic cellulites
Anaerobic myositis or gas gangrene
45. GAS GANGRENE
Low oxygen tension
Battle wounds
Implanted bullets with bits
clothing & soil
Ionised calcium salts & silicic-
necerosis
Crushing of tissuce or tearing
of arteries – anoxia of muscle
Reduction – blood supply
Extravasation Hb and Myo
Hb – Reduced
Aerobic oxidation – hatled
Anaerobic – Pyruvate to
lactate - i Eh
47. Incubation period → 2 days to several weeks
commonly 6-12 days
Disease developes with ↑ in pain
edema
tenderness
thin watery discharge
perfuse & serosanguinous
accumulation of gas makes tissue
crepitant
48. LAB DIAGNOSIS
Specimens – collected
1) Films – muscles – at the edge
necrotic area
exudates
2) Exudates – capillary pipette or swab
3) Necrotic tissue & muscle fragments
GRAM STAINING
Large – regular-Cl.perfringens
“ Cirtonbodies” – irregular staining – Cl.septicum
Large bacilli – Oval subterminal spores – Cl.novyi
Slender – round terminal spore -Cl. Tetani
52. CULTURAL CHARCTERISTICS
Obligatory anaerobes
Opt. temp 37ºC
pH 7.4
Grows on ordinary media
growth increases by blood and serum
Extremely fine transluscent
53. BIOCHEMICAL REACTIONS
MR –ve
VP – ve
H2S not formed
Indole formed
Nitrates not reduced
Gelatin Liquefied
54. EPIDEMIOLOGY
INDIA
Tetanus-Important epidemic infection in
india.
Prior-NIP-3.5 lakh children died annually-NT
1993-94-2.8 Lakh-NT-everted
>50%-NT-month-july-aug.-sep.
Male infants more susceptible-no bio.
Reasons.
55.
56. RESISTANCE
Spores-killed-boiling 10-50 mg
Autoclaving – 1210C – 20 min.
Iodine & hydrogen peroxide kill – spores – few
hrs.
CLASSIFICATION
Ten serological types (Type I to type X)
TOXIN :- Two toxin, Tetanolysin,Tetanospasmin
57. PATHOGENICITY
Toxin – absorbed – motor nerve endings
Transported- CNS – intraaxonally
Toxin – fixed – gangliosides – grey matter of nervous
tissue
Tetanus toxin – blocks synaptic inhibition in spinal
cord ( GABA)
Uncontrolled spread of impulses in CNS
Muscle rigidity
Spasms- due to contraction of agonists & antagonist
59. TETANUS
Tonic muscular spasms
cowdung – umbilical stumps
Circumcision & earboring
IP- 2 days to several weeks
CLINICAL MANIFESTATION OF TETANUS
First notice - h muscle tone in masseter
TRISUMS / LOCK JAW
Dysphagia or pain in neck, shoulder, back muscle
Rigid abdomen & stiff proximal limb muscles
RISUS SARDONICUS – Contraction of fascial muscles
OPISTHO TONOS – Arched back
Paroxysmal spasm – Cyanosis
60. NEONATAL TETANUS
Children born –
Inadequately immunized mother
First 3 weeks of life
Poor feeding, rigidity, spasms
CEPHALIC TETANUS
Followed - Injury – head & ear infections
Trismus, Dysfunction
63. PROPHYLAXSIS
Surgical attention
Anti biotics – Pencillin inj
Erythromycin –
500 mg, b.d. 5 days
Neomycin –
locally.
Passive immunisation – Inj
tetanus antitoxin
ATS – hyperimmune horse
1500 IU – SC, IM in –
nonimmune persons
Disadvantages – immune
elimination
Hypersensitivity
64. PROPHYLAXSIS
Active immunisation –Inj,
toxoid 3 doses IM
4-6 weeks intervals b/w
first 2 Inj
3rd dose 6 mth later
Booster doses ten yrs
Combined immunisation
TIG at one side
Toxoid – first dose –
contralateral
2nd, 3rd doses-monthly
intervals
65. TREATMENT
Antibiotic :- Pencillin ( 10-12 Million units IV – 10 days)
or
Metronidazole
Spasm control :- Diazepam of lorazepam,
Barbiturates & cholorpromazine – 2nd
line agents
R.C:- Incubation or tracheostomy
Autonomic dysfunction :- Labtalol
Esmolol
Clonidine
Morphinesulphate
66. MCQ’s
1.Colonies of Cl. Difficle fluoresce under Wood’s lamp to give
colour which is
A. green B. brick red
C. yellow D. pink
2. Most clostridia are motile except.
A. Cl.tetani B.Cl.novyi
C. Cl.perfringes D.Cl.septicum
3.The capsulated spieces of Clostridium is.
A.Cl.perfringens B.Cl.tetani
C.Cl.histolyticum D.Cl.sporogenes
67. 4.All following clostridia are predominantly saccharolytic
except.
A. Cl.perfringens B.Cl. Septicum
C. Cl.fallax D. Cl.histoyticu
5.Proteolytic clostridia.
A. Digest protiens B. liquefy gelatin
C. liquefy coagulated serum D. all above are true
68. 6.Lecithinase activity can be demonstrated on.
A. egg yolk agar B. MacConkey agar
C. blood agar D. phenolphthalein
7.Stromy clot is almost exclusively produced by.
A. Cl.perfringes B. Cl.tetani
C. Cl.sporogenes D. Cl.novyi
69. The Clostridium which produce swarming growth.
A. Cl. Tetani B. Cl.novyi
B. Cl.perfringens D. Cl. septicum
8.
9. All following clostridia have terminal spores except.
A. Cl.tetani B. Cl. Innocum
C. Cl. cadavers D. Cl.novyi type C
70. LONG ESSAYS:
1.Enumerate the clostridia pathogenic to
humans. Disscus the morphology,cultural characteristics
and toxins of Cl. Welchi.
2.Classify clostridia.Name the diseases produced by
Clostridium welchii. How will investigate such a case?
3.Name the clostridia pathogenic to humans.Describe
the pathogenesis of gas gangrene
71. 4.Enumerate the pathogenic clostridia .Write the steps of
laboratory diagnosis of tetanus?
5.Enumerate the organisms causing gas gangrene .Describe
the morphology of cultural characteristics & pathogenecity of
Cl welchii.add a note on lab diagnosis of gas gangrene?
6.What are gas gangrene clostridia?Describe their
morphology,cultural characteristics & lab diagnosis?
7.Name the pathogenic anaerobic bacteria.Describe the lab
diagnosis of gas gangrene?
8.Enumerate methods of anaerobiosis.Describe the
morphology & cult. Characteristics of Cl tetani.describe the
prophylaxis of tetanus?
9.Describe the morphology, cult. Characteristics of tetanus?
72. SHORT NOTES :
1.Stormy clot reaction.
2.Toxins of Cl welchii.
3.Nagler’s reaction.
4.Pathogenesis & immunoprophylaxis of tetanus.
SHORT ANSWERS :
1.Gas gangrene.
2.Name 4 clostridia causing gas gangrene.
3.Diagnosis of gas gangrene.
4.Morphology of Cl tetani.