Study objective: To assess the value of the initial
microbiological studies (MBS), consisting of sputum Gram’s stains,
sputum cultures, and blood cultures, in the etiologic diagnosis of
community-acquired pneumonia (CAP) without comorbidity.
Design: A prospective study of 74 adult patients
hospitalized with nonsevere CAP empirically treated according to the
American Thoracic Society guidelines (ATS-GL) and evaluated with
Gram’s stains and cultures of valid sputum specimens and blood
Setting: University-affiliated community
Results: Gram’s stain of a valid sputum
specimen failed to identify the etiologic agent in all patients. Sputum
cultures identified pathogens in only four patients (5%). The results
of all blood cultures were negative. All patients responded to the
initial empiric antibiotic coverage selected according to the ATS-GL,
and the results of the initial MBS had no clinical impact.
Conclusion: The initial MBS, such as sputum Gram’s stains,
sputum cultures, and blood cultures, have no value in the management of
nonsevere CAP without comorbid factors.