Which statement about oxygen requirements for pathogens is accurate?

Which statement about oxygen requirements for pathogens is accurate?

• A. All pathogens require oxygen
• B. Some pathogens require oxygen
• C. No pathogens require oxygen
• D. Oxygen inhibits all growth

Answer: (B)

Pathogens have different oxygen needs. Some require oxygen to grow, while others can grow without it or are harmed by it, and many can adapt to either condition. This variability means it’s accurate to say that some pathogens require oxygen—there are aerobes among pathogens that rely on aerobic respiration. For example, obligate aerobes like Mycobacterium tuberculosis need oxygen, whereas obligate anaerobes like certain Clostridium species cannot tolerate oxygen, and facultative anaerobes such as Staphylococcus aureus can grow with or without oxygen. The other statements are too absolute: not all pathogens require oxygen, oxygen doesn’t inhibit all growth, and some pathogens certainly do depend on oxygen for their growth.

Pathogens have different oxygen needs. Some require oxygen to grow, while others can grow without it or are harmed by it, and many can adapt to either condition. This variability means it’s accurate to say that some pathogens require oxygen—there are aerobes among pathogens that rely on aerobic respiration. For example, obligate aerobes like Mycobacterium tuberculosis need oxygen, whereas obligate anaerobes like certain Clostridium species cannot tolerate oxygen, and facultative anaerobes such as Staphylococcus aureus can grow with or without oxygen. The other statements are too absolute: not all pathogens require oxygen, oxygen doesn’t inhibit all growth, and some pathogens certainly do depend on oxygen for their growth.