Nosocomial Enterobacter Meningitis: Risk Factors, Management, and Treatment Outcomes

Enterobacter species are increasingly a cause of nosocomial meningitis among neurosurgery patients, but risk factors for these infections are not well defined. A review of all adult patients hospitalized at the University of California-Los Angeles (UCLA) Medical Center during an 8-year period identified 15 postneurosurgical cases of Enterobacter meningitis (EM). Cure was achieved in 14 cases (93%), and efficacy was similar for carbapenem- and cephalosporin-based treatment. A matched case-control study comparing 26 controls with 13 case patients hospitalized exclusively at the UCLA Medical Center found that external cerebrospinal fluid (CSF) drainage devices (odds ratio [OR], 21.8; P=.001), isolation of Enterobacter species from a non-CSF culture (OR, 24.6; P=.002), and prolonged administration of antimicrobial drugs before the diagnosis of meningitis that were inactive in vitro against Enterobacter species (OR, 13.3; P=.008) were independent risk factors for EM. Despite favorable treatment outcomes, EM is a serious infection associated with Enterobacter species colonization or infection at other surgical sites, with selective antimicrobial pressure, and with invasive CNS devices.