Gangrene is defined as necrotic tissue infected by bacteria. Which option best matches this definition?

• A. Inflammation without tissue death
• B. Necrotic tissue infected by bacteria
• C. Necrosis due to vascular occlusion
• D. Primary tissue necrosis without infection

Answer: (B)

Gangrene is tissue that has died (necrosis) and is infected by bacteria. The defining feature is the combination of dead tissue with bacterial invasion, which can drive further damage and systemic illness, especially in wet or gas gangrene.

The other descriptions miss a key part: inflammation without tissue death describes tissue that hasn’t necrosed; necrosis due to vascular occlusion describes dry gangrene without infection; and necrosis without infection describes tissue death but not the infectious component. So the description that pairs necrosis with bacterial infection best matches the concept of gangrene.