[Molecular features of beta-hemolytic streptococci isolated from blood in adult invasive infection and the clinical background factors].

: We studied the relationship between features of beta-hemolytic streptococci (n = 45) isolated from blood in adult invasive infection and the clinical background factors observed from January 2001 through August at a hospital for the elderly. The meanage of subjects having invasive streptococcal infection with 22 invasive Streptococcus dysgalactiae subspecies equisimilis (SDSE) strains, 2 S. pyogenes isolates, and 21 S. agalactiae (GBS) was 80 years, and 85.7% and 86.4% had underly diseases in the GBS and SDSE infections. SDSE-infected were mainly emergency woman outpatients and GBS infected were mainly man inpatients. The clinical syndrome involved pneumonia, urosepsis, and cellulitis. GBS mortality was 14.3% and SDSE mortality 27.3%. Compared to survivors, nonsurvivors had more thrombocytopenia and marked serum C-reactive protein elevation when blood culture were performed. No difference was seen in white blood cell count between bath groups. Our observations suggest that blood culture should be obtained before antimicrobials administration in elderly individuals with underlying illness who are seen at the emergency department and have laboratory blood data suggestive of infectious disease.