Table 2.

Isolation of bacteria from patients admitted with severe community acquired pneumonia (n = 189)

Etiological agent	No. of patients with positive cultures	No. of patients who died
Staphylococcus aureus (7 from blood culture, 5 from tracheal aspirate, 1 from BAL, 2 from sputum)	15	8 (53)
Streptococcus pneumonia (11 from blood culture, 1 from tracheal aspirate, 2 from sputum)	14	4 (29)
Pseudomonas aeruginosa (3 from blood culture, 3 from tracheal aspirate, 2 from BAL, 1 from sputum)	9	8 (89)
Klebsiella pneumonia (5 from tracheal aspirate, 1 from BAL)	6	3 (50)
Mycobacterium tuberculosis (2 from BAL)	2	1 (50)
Moraxella catarrhalis (Tracheal aspirate)	1	1 (100)
Burkholderia pseudomallei (Tracheal aspirate)	1	1 (100)
Nocardia asteroids (Pleural fluid)	1	1 (100)
Streptococcus milleri (Pleural fluid)	1	0
Number of pathogens isolated	50	27 (54)
Number of patients with known etiology*	47	25 (53)
Number of patients with unknown etiology	142	71 (50)

The values in the brackets are the percentages of patients who died with positive cultures.

*Three patients had dual etiologies: Staphylococcus aureus and Pseudomonas aeruginosa in two and Pseudomonas aeruginosa and Nocardia asteroides in one patient.