Final answer:
Gangrene is the predisposing factor for infection by Clostridium perfringens, as it creates an oxygen-deprived environment conducive to the growth of this obligate anaerobe.
Step-by-step explanation:
A predisposing factor for infection by Clostridium perfringens is gangrene. Gangrene occurs when blood flow to a region of the body is interrupted, causing tissues to die and create an anaerobic environment. This environment is ideal for the growth of C. perfringens, an obligate anaerobe that grows in oxygen-deprived tissue. Deep puncture wounds, traumatic injuries, or medical conditions like diabetes can lead to ischemia, allowing the endospores of C. perfringens to germinate in these ischemic tissues and lead to severe infections such as gas gangrene.
It's important to note that while surgical debridement and hyperbaric treatment are strategies used to treat gas gangrene, they are not factors that predispose a person to the infection. On the contrary, debridement refers to the removal of dead and infected tissue to prevent the spread of bacteria, and hyperbaric oxygen therapy is used to kill anaerobic bacteria like C. perfringens.