A 76-year-old man who has been a smoker since his teenage years was admitted with a right lower lung lobe infiltrate. A diagnosis of pneumonia was strongly considered and the patient was admitted to the hospital. Which of the following agents is not associated with adult community acquired pneumonia?

Chlamydia trachomatis Chlamydia pneumoniae, not C. trachomatis, is associated with adult pneumonia. C. trachomatis can cause pneumonia in infants following acquisition during the passage through an infected bih canal. Streptococcus pneumoniae and Mycoplasma pneumoniae are by far the most common causes of community acquired pneumonia. Haemophilus influenzae is commonly associated with chronic lung disease. Legionella pneumophila is common in ceain geographic areas and has also been associated with outbreaks.