[Clinical significance of Streptococcus milleri isolated from various suppurative lesions].

Seventy-one strains of Streptococcus milleri were isolated from 68 patients admitted to Tamana Central Hospital. (1985.2-1989.1) S. milleri was isolated from the following specimens: sputum (15 strains), urine (10), ascites (9), postoperative wound (9), pleural effusate (6), bile (5), genital discharge (3), aspirated fluid from lung abscess (2) and others (12). In 12 patients (18%), S. milleri was isolated in pure culture and in 56 patients (82%) as part of a mixed flora. Other bacteria isolated in association with S. milleri were obligate anaerobes (41%), Gram-negative rods (40%), Gram-positive cocci (16%) and others (3%). In 71 strains of S. milleri, 9 strains (13%) were beta-haemolytic, 62 (87%) were alpha-haemolytic (week) or non-haemolytic. In 68 patients, type specific male-female ratio was 15:9 for S. milleri I, 20:15 for II and 1:8 for III respectively. The patient's age ranged from 7 to 86 years and 75% of patients were more than 50 years old. In respiratory infection, 10 cases (pyothorax, 6; pneumonia, 3; lung abscess, 1) were related to S. milleri infection and considered clinically significant. 8 cases had underlying disease, however, 2 cases (pyothorax, lung abscess) had no underlying disease. In these 2 cases, S. milleri was isolated in pure culture. Successful treatment of these ten cases usually required either antibiotic therapy or drainage of the lesion. S. milleri was isolated from various clinical specimens and some cases were associated with serious infections. S. milleri was more commonly associated with suppurative infections than other viridans group streptococci. S. milleri may therefore have different characteristics which other streptococcal species of normal flora have not.