Question

Porphyromonas invades tissues Question 15 (2 points) These are the steps in the development of gas gangrene. Place them in order and indicate which one would come fourth Clostridium perfringens grows and multiplies on dead cell nutrients Clostridium perfringens kills and invades surrounding tissues Clostridium perfringens spores from environment (e.g., soil) germinate in wound Blood supply to tissue is interrupted by a wound, causing anaerobic conditions and cell death Clostridium perfringens ferments carbohydrates, producing CO2 and H2

Answer 1

Answer - in sequence of occurrence a) Blood supply to tissue is interrupted by a wound, causing anaerobic conditions and cell death b) Clostridium perfringens spores from environment germinate in wound c) Clostridium perfringens kills and invades surrounding tissue d) Clostridium perfringens grows and multiplies on dead cell nutrients e) Clostridium perfringens ferments carbohydrates, producing CO2 and H2 Explanation Clostridium perfringens is an anaerobic bacterium. So it needs oxygen free environment. When wound is formed it causes stagnation of blood. Which in turn stop oxygen supply to that tissue. When clostridium perfringens spore get landed on this favourable surface it start killing surrounding tissue. There it multiplies on dead cell nutrients. It ferment carbohydrates of cells to carbon dioxide and hydrogen. Note: the gas thus formed get trapped in tissues and results in dreaded condition called GAS GANGRENE.