Purpose: Our study is a retrospective observational study conducted in one of the largest clinical centers of neurosurgery in China. We aimed to investigate the antimicrobial susceptibility patterns of the Enterobacteriaceae  isolates responsible for nosocomial meningitis/encephalitis in post-neurosurgical patients. Meanwhile, we tried to evaluate the risk factors for mortality following Enterobacteriaceae  meningitis/encephalitis.
Patients and Methods: Medical data on clinical characteristics, antibiotic susceptibilities, and mortality were reviewed until patients’ discharge or death in the hospital. Data for a total of 164 cerebrospinal fluid (CSF) infection cases due to Enterobacteriaceae  after neurosurgery were collected between January 2014 and November 2019 in order to identify risk factors affecting the outcome. Kaplan–Meier survival analysis and multivariable Cox proportional hazard models were applied.
Results: In this study, a total of 2416 neurosurgical meningitis/encephalitis cases were reported between 2014 and 2019. Enterobacteriaceae  accounted for 7.3% (176/2416) of all the bacterial infections. Of them, 164 Enterobacteriaceae  isolates were available to divide into two groups according to the final outcome of whether the patient died or survived. In total, 38 patients died (23.2%) and 126 patients survived (76.8%). The most frequent infecting species was Klebsiella pneumoniae  (47.0%, 77/164). Fourteen-day and 30-day mortality rates were 7.9% (13/164) and 15.2% (25/164). Kaplan–Meier survival analysis revealed that the risk factors of Enterobacteriaceae  meningitis/encephalitis that resulted in poor outcomes included comorbidities, Glasgow Coma Scale (GCS) score, sepsis, intensive care unit (ICU) admission, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae , and ventilation. A GCS score of less than or equal to 8 (P=0.04, HR 2.562) was identified to be a significant risk factor for mortality according to the multivariable Cox proportional hazards model.
Conclusion: In-hospital mortality caused by Enterobacteriaceae  meningitis/encephalitis in neurosurgery was high. A GCS score of ≤ 8 was an independent risk factor for mortality following Enterobacteriaceae  meningitis/encephalitis in post-neurosurgical patients.
Keywords: Enterobacteriaceae , post-neurosurgical meningitis/encephalitis, antibiotic susceptibility, antibiotic resistance, in-hospital mortality