Do all pathogens require oxygen to grow?

Do all pathogens require oxygen to grow?

• A. Yes
• B. No
• C. Only in water
• D. Always in warm temperatures

Answer: (B)

Oxygen availability isn’t the same for every pathogen. Some pathogens are obligate aerobes and must have oxygen to grow, while others are obligate anaerobes and are harmed by oxygen. Many human pathogens are facultative anaerobes, meaning they can grow with or without oxygen, so they can colonize both oxygen-rich areas and low-oxygen sites like the gut. There are also microaerophiles that need only small amounts of oxygen. Because of this diversity, not all pathogens require oxygen to grow. Temperature and moisture also influence growth, but oxygen needs vary independently of those factors, so the statement about always needing oxygen isn’t correct.

Oxygen availability isn’t the same for every pathogen. Some pathogens are obligate aerobes and must have oxygen to grow, while others are obligate anaerobes and are harmed by oxygen. Many human pathogens are facultative anaerobes, meaning they can grow with or without oxygen, so they can colonize both oxygen-rich areas and low-oxygen sites like the gut. There are also microaerophiles that need only small amounts of oxygen. Because of this diversity, not all pathogens require oxygen to grow. Temperature and moisture also influence growth, but oxygen needs vary independently of those factors, so the statement about always needing oxygen isn’t correct.