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Learn about Clostridium spores, their survival mechanism, and characteristics based on position, size, and shape. Explore Clostridium spp., such as C. perfringens and C. botulinum, and their distinct spore types. Discover insights into associated human diseases and virulence factors.
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Spores • Clostridium form endospores under adverse environmental conditions • Spores are a survival mechanism • Spores are characterized on the basis of position, size and shape • Most Clostridium spp., including C. perfringens and C. botulinum, have ovoid subterminal (OST) spores • C. tetani have round terminal (RT) spores
NOTE:Large rectangular gram-positive bacilli NOTE:Double zone of hemolysis Inner beta-hemolysis = θ toxin Outer alpha-hemolysis = α toxin Micro & Macroscopic C. perfringens
Major Minor C. perfringens Virulence Factors
C. perfringens Nagler Reaction NOTE: Lecithinase (α-toxin; phospholipase) hydrolyzes phospholipids in egg-yolk agar around streak on right. Antibody against α-toxin inhibits activity around left streak.
Clostridium tetani Gram Stain NOTE: Round terminal spores give cells a “drumstick” or “tennis racket” appearance.
REVIEW Clostridium
Spores • Clostridium form endospores under adverse environmental conditions • Spores are a survival mechanism • Spores are characterized on the basis of position, size and shape • Most Clostridium spp., including C. perfringens and C. botulinum, have ovoid subterminal (OST) spores • C. tetani have round terminal (RT) spores REVIEW
NOTE:Large rectangular gram-positive bacilli NOTE:Double zone of hemolysis Inner beta-hemolysis = θ toxin Outer alpha-hemolysis = α toxin Micro & Macroscopic C. perfringens REVIEW
Major Minor C. perfringens Virulence Factors REVIEW
Exotoxins Associated with C. perfringens Types A-E Major REVIEW
C. perfringens Nagler Reaction NOTE: Lecithinase (α-toxin; phospholipase) hydrolyzes phospholipids in egg-yolk agar around streak on right. Antibody against α-toxin inhibits activity around left streak. REVIEW
Clostridium tetani Gram Stain NOTE: Round terminal spores give cells a “drumstick” or “tennis racket” appearance. REVIEW
Clinical Forms of Tetanus REVIEW