A retrospective study of prevalence and antibiotic resistance of bacteria isolated from the cerebrospinal fluid of neurosurgical patients in a Shanghai tertiary hospital

Abstract Background: Postoperative central nervous system infections (PCNSIs) are serious complications following neurosurgery. Effective management of the infections depends on the identification of causative pathogens and the antibiotic sensitivities. The aim of this study was to investigate the clinical features, causative organisms and their antimicrobial susceptibility testing results, which could help clinicians to initiate appropriate empirical antibiotic therapy. Methods: This was a retrospective study conducted over a period of 3.5 years (from January 2016 to July 2019). All in-patients admitted neurosurgery and ICU meeting the inclusion criteria of PCNSIs were included in the study. Demographic characteristics, type of neurosurgery, laboratory data, causative organisms and antimicrobial susceptibility testing results were analyzed. Results: A total of 1500 patients underwent operation during this study. Twenty-three patients with 34 isolates out of 79 patients with 157 CSF culture samples were available for data analysis. The estimated incidence and culture-positive rate of PCNSIs were approximately 1.5% and 29.1%, respectively. The predominant organism was coagulase-negative staphylococci, of which most were methicillin-resistant coagulase-negative staphylococci (MRCoNS). All were susceptible to vancomycin, linezolid, and rifampicin. Acinetobacter baumannii was the most frequent causative Gram-negative agent and was resistant to 14 out of 17 antimicrobials tested. The sensitivity rates for amikacin, sulfamethoxazole-trimethoprim and minocycline were only 44, 44, and 11%, respectively. Conclusions: The MRCoNS were the predominant organism for PCNSIs. The management of Acinetobacter baumannii could be a major clinical challenge with few effective antimicrobials in PCNSIs.