Ru Yang,1,* Wen Wang,1,2,* Guomin Yin,1,2 Tingting Ma,1,2 Jia Tao1,2 

1Center of Medical Laboratory, General Hospital of Ningxia Medical University, Yinchuan, 750004, People’s Republic of China; 2Ningxia Key Laboratory of Clinical and Pathogenic Microbiology, General Hospital of Ningxia Medical University, Yinchuan, 750004, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Jia Tao, Email taojia880625@163.com

Objective: During conditions accompanied by the disruption of normal mucosal barriers, anaerobic bacteria, which a part of normal human mucosal microflora, may cause various infections. In this study, clinical features of anaerobic bloodstream infections (BSI) in a general hospital in China were investigated.
Methods: Patients with anaerobic BSI were retrospectively enrolled between 2012 and 2022. Demographic data, clinical manifestations, antibiotic treatments, and disease outcomes were analyzed.
Results: In total, 391 anaerobic bacterial strains were isolated from 381 patients aged older than 11 years of age. Given that medical records of 47 patients were missing, 334 patients were included in the clinical investigation. Patients with anaerobic BSI included in the study were predominantly older than 50 years of age. Intra-abdominal infections were the most common source of anaerobic BSI (59%), followed by those of the female genital tract (10.2%) and lower respiratory tract (7.2%). Among the isolates, Bacteroides and Clostridium spp. were the most frequently isolated anaerobes. Most of the patients received antibiotic therapy. The crude mortality was 4.5%.
Conclusion: The detection rate of anaerobic BSI in Ningxia, China, remained relatively stable from 2012 to 2022. These results provide a reference for the diagnosis and empirical treatment of anaerobic BSI in this region of China. Continuous mul-ticenter studies should be conducted to monitor the incidence of anaerobic BSI and drug resistance of anaerobic isolates to improve the treatment outcomes of patients.

Keywords: anaerobes, bloodstream infections, blood cultures, clinical features