Mixed Streptococcus pneumoniae and gram-negative bacillary pneumonia in the elderly.

Of 24 elderly patients with Streptococcus pneumoniae pneumonia confirmed by transtracheal aspiration, six had concomitant infection with gram-negative aerobic bacilli. All six patients were elderly men with underlying cardiopulmonary disease. Three had had recent prior episodes of gram-negative pneumonia and four had previously received antibiotics. The clinical, laboratory, and epidemiologic characteristics of these six patients with mixed bacterial pneumonia are reported.