Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

Which specimen requires anaerobic culture?

1. Fungus

2. Brain abscess

3. Stool

4. Sputum

The correct answer is: Brain abscess

Anaerobic cultures are specifically used to identify organisms that thrive in low or absent oxygen conditions. Among the options provided, a brain abscess is the correct specimen that typically requires anaerobic culture because these abscesses often contain anaerobic bacteria, which can be responsible for polymicrobial infections. In clinical scenarios, brain abscesses can arise from infections that involve the oral cavity or sinuses, where anaerobes commonly reside. The presence of these bacteria is crucial to accurately diagnosing and treating the infection, as they can significantly impact the choice of antimicrobial therapy. The other specimens listed do not typically require anaerobic cultures. For example, fungus can be cultured in aerobic environments, stool samples are generally tested for both aerobic and anaerobic organisms but do not specifically require anaerobic culture unless there is a suspicion of particular anaerobic pathogens. Sputum is primarily analyzed for aerobic bacteria, and while it may contain some anaerobic organisms, the primary culture methods employed usually do not focus on anaerobes. Therefore, a brain abscess stands out as the specimen most commonly necessitating anaerobic culture to identify its specific pathogens accurately.