Streptococcus dysgalactiae subsp. equisimilis bacteremia: Emm types and clinical characteristics-a 4-year prospective study

Abstract

OBJECTIVES: The incidence of Streptococcus dysgalactiae subspecies equisimilis (SDSE) bacteremia is increasing worldwide, yet studies linking emm types to clinical data remain limited. This study aimed to investigate associations between emm types, clinical manifestations, and disease severity in patients with SDSE bacteremia.METHODS: We prospectively studied 159 SDSE bacteremia episodes in Pirkanmaa, Finland (November 2015 to November 2019). Severe disease was defined as intensive care unit treatment and/or death within 30 days of hospital admission.RESULTS: While emm type stG480 has remained the most common, stG62647 has increased over tenfold to become the second most prevalent. Emm type stC74a was associated with intensive care unit treatment (odds ratio [OR] 5.8 [95% confidence interval (CI) 1.3-26)]), severe disease (OR 5.2 [95% CI 1.4-19]), and predominance of male patients (OR 8.5 [95% CI 1.1-67]). Surgical interventions were linked to emm type stG62647 (OR 2.8 [95% CI 1.1-7.3]). Potential associations between emm type and clinical manifestations were observed: stG643 with endocarditis, stG62647 with foreign-body infections, stG2078 with abscesses, and stG485 with unknown focus.CONCLUSIONS: These results emphasize the importance of emm types in connection with disease severity and clinical manifestations.