Isolation of beta-hemolytic streptococci from the respiratory tract: distribution and clinical significance.

Isolates of beta-hemolytic streptococci obtained from respiratory tract specimens were studied for determination of their serogroup, and Patients' charts were reviewed for the clinical significance of these respiratory isolates. Fifteen of 69 patients were considered to have definite respiratory infection. Thirteen of these 15 patients had Group B beta-hemolytic streptococci. Staphylococcus aureus was isolated concomitantly with Group B streptococci (GBS) in 34% of cases, but rarely was it isolated with other beta-hemolytic streptococci. Sero-groups of beta-hemolytic streptococci were compared with respect to the patient's underlying disease, age, and clinical outcome. Patients who had GBS isolated from sputum were elderly (mean age, 68.1 years) and were older than patients with other beta-hemolytic isolates (mean age, 56 years). Patients with Group B streptococci were more likely to have cerebrovascular disease, whereas patients with Group C, G, and F were more likely to have malignancy, particularly of the head and neck.