Clostridium

Question 1

Diagnosis of Clostridium difficile - “Pseudomembranous Coltis”

Answer 1

Gram (+), Rod-shaped, spore-forming, anaerobic (obligate anaerobe)
–> resistant to disinfectants & alcohol

Question 2

Infection route of Clostridium difficile

Answer 2

–> Important cause of nosocomial infections
–> soil, meat, vegetables

Question 3

pathogenesis/ VF of Clostridium difficile - “Pseudomembranous Coltis

Answer 3

Bowel microbiota disruption (Dysbiosis)
-only toxin-producing strains cause disease

VF: TcdA & TcdB –> induce the production of cytokines–> inflammatory colitis with neutrophils

Question 4

Treatment of Clostridium difficile - “Pseudomembranous Coltis

Answer 4

-Probiotic for prevention
-colectomy
-DON’T treat asymptomatic patients
-patient isolation measures (inc 48hrs after Diarrhoea has resolved)
- water & soap
- oral Vancomycin ?

Question 5

Clinical manifestations of Clostridium difficile

Answer 5

1) Dehydration and electrolyte loss
2) Acute renal failure
3) TOXIC MEGACOLON
4) Bowel perforation and &sepsis
5) Paralytic ileus
6) Pseudomembraneous colitis
7) Green & malodorous diarrhea
(inflammatory diarrhea with fever and leukocytosis)

Question 6

Diagnosis of Clostridium Perfringens
aka Clostridium Myonecrosis

Answer 6

β-hemolytic, Gram(+), box-shaped rods
–> Rarely forms spores, anaerobic
(obligate anaerobes)

–> Clostridium Myonecrosis is aka GAS GANGRENE

Question 7

Infection route of Clodtridium perfringens

Answer 7

1) Traumatic injury contaminated with clostridial spores

2) Enterotoxins: meat products not properly cooked or contaminated with enterotoxin-producing C.perfringens

3) Part of normal GI-tract flora & vaginal microflora

Question 8

Pathogenisis/VF of Clostridium perfringens

Answer 8

–> Major leathal toxins (α,β,ε,ι)
–> Exotoxin production (lecithinase)
–> Enterotoxins

Question 9

Clinical Manifestations of Clostridium perfringens

Answer 9

1) Myonecrosis (GAS GANGRENE)
2) extreme pain
3) brown or purple skin discolouration
4) Oedema
5) Maldorous gas
6) Hemorrhagic bullae

clinical features casued by Enterotoxins:
1) Nausea or Vomiting
2) watery Diarrhea <24h
3) NO fever

others :
1)Abdominal infection
2) Biliary tract infections
3) female genital tract infections

Question 10

Treatment for C.perfringens

Answer 10

Debridement and Antibiotics

*Abx does not work on enterotoxins, it’s self-limiting

Question 11

Diagnosis of Clostridium Botulinum

Answer 11

Gram (+), spore-forming, anaerobic rod

Question 12

Infection route of C.Botulinum

Answer 12

Spores in soil &marine sediment
–> Improper canning of food

Question 13

Pathogenisis/VF of C.Botulinum
+ the adverse effects of the VF

Answer 13

Botulinum toxin A,B,E,F

*Botulinum toxin affects the PNS only, NOT the CNS (because it cannot cross the BBB)
*It prevents the release of ACh and blocks transmission at peripheral Cholinergic Synapses –> Flaccid Paralysis

Question 14

Clinical Manifestations of C.Botulinum

Answer 14

1. FEVER ABSENT
2. SYMMETRICAL NEUROLOGIC MANIFESTATIONS (symmetrical descending weakness)
3. PATIENT REMAINS RESPONSIVE
4. HEART RATE IS NORMAL OR SLOW
5. NO SENSORY DEFICITS EXCEPT BLURRED VISION
6. Flaccid paralysis

Question 15

Treatment of C.Botulinum

Answer 15

1. Purgatives (if contaminated food still in GI)
2. Heptavalent botulinum antitoxin
3. debridement + antibiotics
4. Ventilation & ICU

Question 16

Diagnosis of Clostridim Tetani

Answer 16

drumstick appearance, Gram (+) rod, obligate anaerobic, spore-forming & toxin-producing.

Question 17

what are the 4 clinical types of C.tetani

Answer 17

• C.tetani can be Generalised, localised, cephalic or neonatal

Question 18

Infection route of C.tetani

Answer 18

–> spores in soil,
–> Transiently colonize GI tract
–> puncture wounds

Question 19

Pathogenesis/VF of C.tetani + adverse effects of the VFs

Answer 19

2 Toxins:
*1) Tetanospasmin:
- Leaves motor neurons without inhibition–> Spastic paralysis
- ANS failure to inhibit adrenal release of catecholamines–> Hypersympathetic state

2)Tetanolysin: Hemolysin of unknown significance

Question 20

Clinical Manifestations of C.tetani

Answer 20

1) risus sardonicus” & “trismus” (lockjaw),
2) drooling
3) irritability
4) Opisthotonic posturing (Generalized spasm)
5) Arrhythmias
6) bp fluctuations
7) Profound sweating
8) extreme pain
9) NO loss of consciousness

Question 21

Treatment for C.tetani

Answer 21

Vaccines:
1) DTaP
2)Tdap
3) Td