Which of the following is NOT a common pathogen for Community-Acquired Pneumonia (CAP)?

In the context of Community-Acquired Pneumonia (CAP), the presence of certain pathogens is more characteristic than others. When considering Clostridium, it is primarily known for causing gastrointestinal infections such as botulism and clostridial myonecrosis, rather than respiratory infections like pneumonia.

On the other hand, Pseudomonas, Haemophilus, and Moraxella are recognized as common pathogens associated with CAP. Pseudomonas aeruginosa typically appears in patients with severe underlying conditions, while Haemophilus influenzae and Moraxella catarrhalis are well-documented causes of pneumonia, especially in settings involving older adults or patients with comorbidities.

Thus, Clostridium does not align with the usual pathogen profile for CAP, making it the correct answer in identifying which option is NOT a common pathogen.