Clostridium Perfringens

Clostridium Perfringens


INTRODUCTION:

  • Anaerobic
  • Shows Stormy fermentation.
  • The spores are usually wider than the rods
  • Spores located terminally or sub terminally.
  • Cl. perfringens is considered as an ideal bac­teriological indicator as acceptability aspect of water
  • Most clostridia are motile by peritrichous flagella. 

 MORPHOLOGY:

  • Large Gram-positive bacilli 
  • Straight, parallel sides & slightly rounded ends.
  • Measure 4-6×1μm in size,occuring singly or in chains
  • Pleomorphic,capsulated & non-motile.
  • Spores are rarely seen in culture media or material from pathogenic lesions, a characteristic morphologic feature

CULTURAL CHARACTERISTICS

  • Robertson’s cooked meat broth is ideal; 
  • meat is turned pink but not digested with sour odor.
  • Stormy fermentation of lactose in litmus milk; the acid coagulates casein-acid clot.

On BAM: 

  • Target haemolysis

BIOCHEMICAL REACTIONS:

Glucose Indole  

Lactose  Fermented with MR

+

Maltose A & G production  VP   

H2S prodn. test

+

Nitrate redn. test

+

TOXINS:    

12 distinct types of Preformed enterotoxins elaborated:

α toxin-

  • lethal,dermonecrotic & hemolytic( principle toxin) 
  • Phospholipase C= lecithinase
  • Associated with gas gangrene
  • Shows Nagler reaction
  • β,ε & ι toxins- lethal & necrotizing
  • γ & η toxins- minor lethal action
  • δ toxin-lethal & hemolytic for red cells

θ toxin-

  • lethal & cytolytic
  • Petfringolysin O.
  • κ toxin- collagenase
  • λ toxin-proteinase & gelatinase
  • μ toxin- hyaluronidase  & ν toxin-deoxyribonuclease
ENZYMES
  • Neuraminidase
  • destroys myxovirus receptors on red cells
  • Hemagglutinin
  • active against red cells of humans
  • Fibrinolysin
  • Hemolysin
  • shows double zone of hemolysis

Lecithinase

  • produce opacity around colonies
  • by spliting lecithin into phosphorylcholine and diacylglycerol
  • appear  opalescence in serum or egg yolk media.

Bursting factor

  • has specific action on muscle tissue
  • responsible for muscle lesions in gas gangrene.

Circulatory factor-

  • causes an increase in adrenaline sensitivity of capillary bed
  • inhibits phagocytosis

Exam Question

INTRODUCTION:

  • Shows Stormy fermentation.
  • The spores are usually wider than the rods
  • Spores located terminally or sub terminally.
  • Cl. perfringens is considered as an ideal bac­teriological indicator as acceptability aspect of water 
  • Spores are rarely seen in culture media or material from pathogenic lesions, a characteristic morphologic feature

TOXINS:    

12 distinct types of Preformed enterotoxins elaborated:

α toxin-

  • lethal,dermonecrotic & hemolytic( principle toxin) 
  • Phospholipase C= lecithinase
  • Associated with gas gangrene
  • Shows Nagler reaction
ENZYMES
  • Hemolysin
  • shows double zone of hemolysis

Lecithinase

  • produce opacity around colonies
  • by spliting lecithin into phosphorylcholine and diacylglycerol
  • appear  opalescence in serum or egg yolk media.
  • Bursting factor
  • Circulatory factor
Don’t Forget to Solve all the previous Year Question asked on Clostridium Perfringens

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