<prompt> Which is the principal virulence factor in Clostridium tetaniTetanolysinTetanospasminTetanotactinImmobility factor  <response>: C.tetani produces two distinct toxins- a hemolysintetanolysin, and neurotoxintetanospasmin. Tetanospasmin: This is the toxin responsible for tetanus. This toxin acts pre-synaptically. The abolition of spinal inhibition causes an uncontrolled spread of impulses initiated anywhere in the central nervous system. This results in muscle rigidity and spasms. Tetanolysin: it is not relevant in the pathogenesis of tetanus. Ref: Textbook of microbiology; Ananthanarayan and panikers; 10th Edition; Pg: 265 