Authors: E Ahlstrand K Svensson L Persson U Tidefelt B Söderquist
Publish Date: 2011/04/05
Volume: 30, Issue: 11, Pages: 1349-1354
Abstract
The aim of this study was to determine if there was a longterm increase in glycopeptide minimum inhibitory concentration MIC values MIC creep among bloodstream isolates of Staphylococcus epidermidis and S haemolyticus isolated from patients with hematological malignancies We conducted a retrospective singlecenter study where all positive blood cultures of S epidermidis n = 387 and S haemolyticus n = 19 isolated from patients with hematological malignancies during three decades 1980 to 2009 were reevaluated for the presence of reduced susceptibility to vancomycin and teicoplanin Three different methods for the detection of reduced susceptibility to glycopeptides were used standard Etest macromethod Etest and glycopeptide resistance detection GRD Etest The median MIC value for vancomycin was 2 mg/L MIC values for vancomycin and teicoplanin did not show any statistically significant increase during the study period The presence of heterogeneously glycopeptideintermediate staphylococci hGIS was analyzed among 405 coagulasenegative staphylococci CoNS isolates hGIS were found in 31–45 of the CoNS isolates by the macromethod Etest and in 53–67 by the GRD Etest during the three decades In conclusion we did not observe any longterm glycopeptide MIC creep determined by the standard Etest although a high and increasing proportion of heterogeneous vancomycin resistance was observed
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