<prompt> All Clostridia cause myonecrosis except-C septicumC difficleCnovyiC welchii  <response>: Ans. is b i.e., C difficle o Anaerobic myonecrosis gas gangrene is caused by-Cl perfringens Cl welchii - most common 80Cl SepticumCl novyiCl histolyticumo Cl difficle causes Clostridium difficle-associated disease CDAD which also includes pseudomembranous enterocolitis. 