Related Experiment Video
Updated: Apr 16, 2026
One-day Workflow Scheme for Bacterial Pathogen Detection and Antimicrobial Resistance Testing from Blood Cultures
Published on: July 9, 2012
Coagulase-negative staphylococcal bloodstream infections: Does vancomycin remain appropriate empiric therapy?
Paula Valencia-Rey1, Janice Weinberg2, Nancy S Miller3
1Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, 771 Albany Street, Dowling Building 3N, Boston, MA 02118, USA.
Objectives:
It is unknown if vancomycin minimal inhibitory concentrations (MICs) have increased in coagulase-negative staphylococci (CoNS) or whether vancomycin remains appropriate empiric therapy.
Methods:
We performed a retrospective study at a single tertiary care center over 8 years. Adult inpatients with ≥2 positive blood cultures for CoNS within a 48-h period were eligible. Susceptibilities were performed by automated broth based-microdilution. Changes in antimicrobial susceptibility were analyzed using logistic regression. The clinical characteristics and outcomes of patients with bloodstream infections (BSI) were compared by MIC.
Results:
Of 308 episodes of possible CoNS bacteremia, the vancomycin MIC was ≤1 μg/mL in 80 (26%) isolates, 2 μg/mL in 223 (72.4%) isolates and 4 μg/mL in 5 (1.6%) isolates. No isolates were resistant. We observed an 11-fold increased chance of having an isolate with a vancomycin MIC ≤1 μg/mL in 2009-2011 compared with 2004-2008 (OR 10.8, 95% CI 6.0-19.5, p < 0.05). In 152 patients with BSI, the median days of bacteremia, hospital mortality and readmissions at 30 days were similar in BSI caused by isolates with high vancomycin MICs (2-4 μg/mL) and low vancomycin MICs (≤1 μg/mL).
Conclusions:
We conclude vancomycin is still appropriate empiric therapy for CoNS BSIs. CoNS vancomycin MICs decreased over the study period despite widespread use of vancomycin.
