Which of the following organisms will grow on agar plates incubated in an anaerobic jar?

• A. Clostridium perfringens
• B. Pseudomonas aeruginosa
• C. Neisseria meningitidis
• D. Bacillus subtilis

Answer: (A)

Verified step by step guidance

1. Understand the concept of oxygen requirements for bacterial growth. Organisms can be classified based on their oxygen tolerance: obligate aerobes require oxygen, obligate anaerobes cannot tolerate oxygen, facultative anaerobes can grow with or without oxygen, and microaerophiles require low oxygen levels.
2. Identify the oxygen requirement of each organism listed: Clostridium perfringens is an obligate anaerobe, Pseudomonas aeruginosa is an obligate aerobe, Neisseria meningitidis is a facultative anaerobe, and Bacillus subtilis is an obligate aerobe or facultative anaerobe depending on conditions.
3. Recall that an anaerobic jar creates an oxygen-free environment suitable for obligate anaerobes and some facultative anaerobes but not for obligate aerobes.
4. Determine which organisms can grow in the anaerobic jar by matching their oxygen requirements to the anaerobic conditions. Obligate anaerobes like Clostridium perfringens will grow, while obligate aerobes like Pseudomonas aeruginosa will not.
5. Conclude that Clostridium perfringens will grow on agar plates incubated in an anaerobic jar because it is an obligate anaerobe, whereas the others will not grow or will grow poorly under these conditions.