Inclusion Criteria:  SCAP AECOPD  Exclusion Criteria:  Pregnant or lactating women.  Patients with bronchiectasis.  Patients with active pulmonary tuberculosis.  Aspiration pneumonia or obstructive pneumonia.  Two weeks before the onset of hospital treatment history, this infection can not be excluded from hospital acquired infection.  HIV positive patients (but HIV testing is not required).  Patients who are unable and / or unable to understand and / or implement the investigation protocol.