Evaluation of predictors of third-generation cephalosporin non-susceptibility and factors affecting recurrence or death in bacteremia caused by Citrobacter freundii complex, Enterobacter cloacae complex, and Klebsiella aerogenes.

Factors involved in the susceptibility of third-generation cephalosporins (3GCs) to bacteremia caused by Citrobacter freundii complex, Enterobacter cloacae complex, and Klebsiella aerogenes were investigated based on a case-case-control design. Antimicrobial therapy administered 30 days prior to bacteremia and hospitalization within 90 days were common risk factors for the 3GC susceptible and 3GC non-susceptible groups, while hospitalization from an institution or another hospital was a specific risk factor for the 3GC non-susceptible group. We also attempted to examine the factors affecting the clinical outcome of bacteremia. Hospitalization more than 14 days before the onset of bacteremia was an independent factor indicating poor clinical outcome. In contrast, the implementation of source control was an independent predictor of successful treatment. Although a longer hospital stay before the onset of bacteremia was associated with worse clinical outcomes, implementation of source control may have contributed to improved treatment outcomes for bacteremia.