Jia Zhou,1,* Xiaoqi Ding,2,* Xinmiao Jia,3 Hongli Sun2 

1Department of Dermatology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, National Clinical Research Center for Dermatologic and Immunologic Diseases, Beijing, 100730, People’s Republic of China; 2Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, People’s Republic of China; 3Center for Bioinformatics, National Infrastructures for Translational Medicine, Institute of Clinical Medicine & Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Hongli Sun, Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, People’s Republic of China, Email sunhl2010@sina.com

Purpose: This study investigated the clinical relevance, pathogenic mechanisms, and neurological involvement of Streptococcus dysgalactiae subspecies equisimilis (SDSE) and subspecies dysgalactiae (SDSD), with a focus on a severe case of SDSE meningitis complicated by septic shock.
Patients and Methods: A systematic review of 19 cases of neurological infections caused by S. dysgalactiae (SDSE or SDSD) from 1971 to 2023 was conducted, supplemented by a detailed case report. Data on patient demographics, predisposing factors, clinical manifestations, diagnostic procedures, treatment, and outcomes were analyzed.
Results: The reviewed cases involved 12 patients with SDSE and seven with SDSD. The median age was 53 years, and most patients had underlying conditions such as diabetes, malignancy, or cardiovascular disease. Neurological manifestations were common, with meningitis being diagnosed in 17 patients. Despite prompt antibiotic therapy, six patients (32%) died, highlighting the severe nature of these infections.
Conclusion: S. dysgalactiae can cause severe neurological infections, particularly in immunocompromised patients. Early recognition and aggressive treatment are essential to improving outcomes. Advanced molecular diagnostic techniques, such as next-generation sequencing (NGS), are crucial in identifying and managing these infections.

Keywords: Streptococcus dysgalactiae, neurological involvement, case report, review