This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Clostridium, Subject name: Microbiology
Needle aspiration from gas gangrene showed gram positive organism with subterminal spores which is the likely organism involved? 
Select and explain. 
A. Cl.perfringens, B. Cl.septicum, C. Cl.novyi, D. Cl.difficile
A: Cl.perfringens
Answer: A: Cl.perfringens 
Explanation: Ans : a) Cl.perfringensGas gangrene:* Incubation period-<3 days* Most common organism: Cl.perfringens '! Cl.novyi'! CLsepticum'! Cl.histolyticum .* Gas gangrene - malignant oedema/ clostridial myonecrosis* Negler reaction: Cl.perfringens* Citron bodies: cl.septicum* Death in gas gangrene: due to circulatory failure* Most important toxin biologically responsible for profound toxaemia of gas gangrene: a toxin (Lecithi- nase C)