Enterobacter species bacteremia: Factors predictive of mortality at a tertiary care institution

The epidemiology and clinical features associated with mortality in patient s with Enterobacter species bacteremia at a large tertiary care institution were investigated in a 10-year longitudinal analysis. The medical records of 134 adult patients with Enterobacter species bloodstream infections from 1986 to 1995 were reviewed. Malignancy (44%), immunosuppressive therapy (2 2.6%), chronic renal insufficiency (18%), and diabetes mellitus (19.4%) wer e significant comorbid illnesses in patients with Enterobacter species bact eremia. Enterobacter cloacae was the most common Enterobacter species isola ted in blood cultures (57%). In 25% of the cases of Enterobacter species ba cteremia, more than one organism was recovered. Although the majority of bl oodstream infections were nosocomially acquired, 31% of the episodes of bac teremia were in patients admitted from the community. The gastrointestinal and genitourinary tracts were the most common sources of secondary bacterem ia (60%). A central indwelling venous catheter was implicated as a source o f the bloodstream infection in 22% of the cases. Mortality in this series o f patients with Enterobacter species bacteremia was 26.9%. By multivariate analysis, age >65 years, intraabdominal source, and need for vasopressor su pport were each predictive of greater mortality. Surgical intervention or r emoval of indwelling catheters was strongly associated with improved surviv al. Resistance of the Enterobacter species blood isolates to third-generati on cephalosporins and broad-spectrum penicillins remained constant at 7% th roughout the study period. Antimicrobial resistance in this study was not s tatistically associated with increased mortality. As a distinct clinical en tity, the occurrence and mortality associated with Enterobacter species bac teremia in patients at a tertiary care institution were associated with dim inished host defenses and increased disease burden.