This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection, Subject name: Surgery
'Gas' in the tissue should be differenciates with: 
Select and explain. 
A. Pseudomyxoma peritonei, B. Pseudomonas infection, C. Clostridium nouyi, D. Non clostridial infection
C: Clostridium nouyi
Answer: C: Clostridium nouyi 
Explanation: (Clostridium novyi) (124-Baily & Love 24th) (CSDT 12th) (109) (422-Baily & Love 25th)GAS - GANGRENE - caused by Clostridium perfringens* Gas and smell (mousy odour) are characteristic and crepitus.* Immunocompromised patients are most at risk.* Antibiotic prophylaxis is essential when performing amputation to remove dead tissues.'Gas' in the tissue is not a good differentiating point since some clostridial species do not produce gas (clostri novyi) since non clostridial organisms often produce gas (E. coli) and since air can enter tissues through a penetrating wound.