Archive for the ‘Clostridium’ Category


What is Clostridium?

Clostridium are a group of bacteria that include:

  1. Clostridium botulism
  2. Clostridium tetani
  3. Clostridium difficile
  4. Clostridium perfringens
  5. Clostridium histolyticum
  6. Clostridium novyi
  7. Clostridium septicum
  8. Clostridium sordellii.

Among them C. botulism, C. tetani, C. difficile, and C. perfringens are medically most important disease producing bacteria. Clostridium are universally found in soil, usually in the form of spore.

Characteristics of Clostridium:

All Clostridium bacteria are spore forming, anaerobic, exotoxin producing, and gram positive rods.

(1) Spore forming: Clostridium form a metabolically inactive highly resistant structure called spore in response to adverse environments. The spore contains a small amount of cytoplasm, DNA, peptidoglycan, very little water, cell membrane, and has a thick keratinlike coat that is responsible for the high resistance of spores to heat, radiation, chemicals, and dyhydration. Spores of Clostridium are not killed by boiling at 1000C but are killed at 1210C. Clostridium are able to survive many years by forming spore. Upon exposure to appropriate environments spores of Clostridium can germinate into potentially active pathogenic bacteria.

(2) Anaerobic: Clostridium are anaerobic bacteria that means they live and grow in low oxygen environments. Clostridium are able to grow only in an environment containing less than 20% oxygen. They grow poorly in room air.

(3) Exotoxin producing: Clostridium secrete a highly toxic substance called exotoxin which is polypeptide in nature. Clostridium cause disease by producing exotoxin. Exotoxins of Clostridium are heat labile and destroyed rapidly at 600C temperature.

(4) Gram positive rod: During gram staining procedure, Clostridium intake gram stain and visualized as blue rod shaped bacteria under microscope. Therefore, they are called gram positive rod.

Diseases producing Clostridium:

Name of Clostridium Disease
C. botulinum Botulism
C. tetani Tetanus
C. difficile Psedomembranous colitis
C. perfringens Gas gangrene and food poisoining
C. histolyticum Gas gangrene
C. novyi Gas gangrene
C. septicum Gas gangrene
C. sordellii Endometritis and Toxic shock syndrome