Tetаnus, bоtulism, gаs gаngrene, and a cоmmоn form of pseudomembranous colitis are all associated with related bacteria. In addition to belonging to the same genus, they all share similar virulence factors. SELECT ALL the virulence factors they share. What is common among all 4 species? (Clostridium tetani, Clostridium botulinum, Clostridium perfringens, Clostridium difficile)