Empiric and targeted treatment of enterococcal infections: Opportunities for antimicrobial stewardship

Background Enterococcal infections are a significant cause of morbidity and mortality. Infections caused by vancomycin-resistant enterococci (VRE) are a growing public health problem. We studied antimicrobial treatment of enterococcal infections to identify opportunities to improve clinical practice. Methods We reviewed retrospective data on patients hospitalized with enterococcal bloodstream infections (EBSIs) and enterococcal urinary tract infections (EUTIs) from 2008 to 2009. For EBSI, the antimicrobial treatment at the time when blood culture Gram-stain results were reported was termed empiric, whereas the antimicrobial treatment when the peptide nucleic acid in situ fluorescence hybridization results were available was termed targeted. For EUTI, the antimicrobial therapy at the time when urine culture indicated enterococci was empiric, and targeted therapy was antimicrobial at the time when susceptibilities were reported. Results Of 65 patients with EBSI, Enterococcus faecalis caused 38 infections, Enterococcus faecium caused 24, and Enterococcus gallinarum caused 3. Vancomycin resistance was demonstrated in 42% of blood isolates; of those, 78% were E. faecium. Overall, 44 patients (68%) with EBSI received vancomycin empirically; of those, 17 patients (39%) had isolates that were VRE. Vancomycin was given as targeted therapy to 12 patients, of which a total of 4 isolates were VRE. Among patients with EUTI who received empiric therapy, 24 (45%) of 53 received vancomycin, of which 10 isolates were VRE. Targeted therapy was given to 56 patients with EUTI, of which 18 received vancomycin and 39% (7/18) were VRE. Conclusions Vancomycin was commonly used for both empiric and targeted therapy. Vancomycin-resistant enterococci was frequent, and empiric therapy was inadequate in most of those cases. Targeted therapy for both EBSI and EUTI was often not tailored to more appropriate agents. Our findings indicate many stewardship opportunities to improve prescribing for enterococcal treatment.