Objective To analyze clinical characteristics, diagnosis and treatment of 39 patients with blood flow infection of Streptococcus dysgalactiae subspecies equisimilis (SDSE).

Methods General data, underlying diseases, clinical manifestations, laboratory tests, drug sensitivity analysis, treatment and outcome of SDSE in 39 patients with 45 episodes of SDSE bloodstream infection were retrospectively analyzed.

Results Of the 39 patients diagnosed with SDSE bloodstream infection, 38 cases (97.4%) had underlying disease. The common underlying disease was malignancy (17 cases, 46.1%). The main clinical manifestations of SDSE bloodstream infection were fever, mainly acute hyperthermia. A total of 16 person-time were diagnosed as erysipelas; 4 person-time were diagnosed with skin and soft tissue infection, and one case was diagnosed as acute lower extremity phlebitis with lymphedema. Four person-time were diagnosed with repeated SDSE bloodstream infection (2 to 3 times). All patients underwent blood culture examination. Only one set of blood culture test was performed in 14 cases, and 31 patients underwent two sets of blood culture tests. A total of 38 samples were positive for aerobic culture, 40 samples were positive for anaerobic culture, and 33 samples were positive for anaerobic and aerobic culture. Leukocyte elevation occurred in 22 cases; elevated neutrophils in 28 cases; leukocyte and neutrophil counts decreased in 3 cases. Forty-two person-time were tested for erythromycin and clindamycin, and the resistance rates were 90.4% and 76.2%, respectively. Empiric anti-infective therapy was given upon admission or after fever, and drugs were selected according to drug sensitivity test after diagnosis of SDSE. The 41 person-time were cured and 4 cases died.

Conclusion Most patients with SDSE bloodstream infection have underlying diseases, and most patients present fever and erysipelas, which are prone to relapse. The first choice for SDSE bloodstream infection is penicillin anti-infective therapy, combined with anti-infective therapy is needed if necessary.