What pathogen is least commonly associated with community-acquired atypical pneumonia?

Community-acquired atypical pneumonia is most commonly associated with pathogens such as Mycoplasma pneumoniae, which is a leading cause, as well as Chlamydia pneumoniae and certain viral infections. Streptococcus pneumoniae, although known for causing classic pneumonia, can also present atypically, particularly in certain populations. Moxarella catarrhalis is more associated with upper respiratory tract infections and is not a primary pathogen in pneumonia.

Pseudomonas aeruginosa, on the other hand, is typically associated with hospital-acquired infections and tends to affect individuals with compromised immune systems or underlying lung disease, such as cystic fibrosis. It is not generally implicated in community-acquired pneumonia, making it the least common pathogen associated with this type of pneumonia. This distinction highlights the prevalence patterns of these pathogens and their typical clinical contexts. Therefore, identifying Pseudomonas aeruginosa as the least commonly associated pathogen with community-acquired atypical pneumonia is accurate based on its epidemiological associations.