M.<unk> e infections can be differentiated from other types of<unk>  by the relatively slow progression of symptoms. A positive blood test for cold-hemagglutinins in 50–70% of patients after 10 days of infection (cold-hemagglutinin-test should be used with caution or not at all, since 50% of the tests are false-positive), lack of bacteria in a Gram-stained sputum sample, and a lack of growth on blood agar. PCR has also been used.
Mycoplasma pneumonia
Mycobacterium tuberculosis
Bordetella pertussis
Pneumocystis jirovecii
Bacillus anthracis
Rhodococcus equi
Legionella
Haemophilus influenzae