Multicenter evaluation of the Staphylococcus QuickFISH method for simultaneous identification of Staphylococcus aureus and coagulase-negative staphylococci directly from blood culture bottles in less than 30 minutes

J Clin Microbiol. 2012 Jun;50(6):1994-8. doi: 10.1128/JCM.00225-12. Epub 2012 Apr 4.

Abstract

A novel rapid peptide nucleic acid fluorescence in situ hybridization (FISH) method, Staphylococcus QuickFISH, for the direct detection of Staphylococcus species from positive blood culture bottles was evaluated in a multicenter clinical study. The method utilizes a microscope slide with predeposited positive- and negative-control organisms and a self-reporting 15-min hybridization step, which eliminates the need for a wash step. Five clinical laboratories tested 722 positive blood culture bottles containing gram-positive cocci in clusters. The sensitivities for detection of Staphylococcus aureus and coagulase-negative staphylococci (CoNS) were 99.5% (217/218) and 98.8% (487/493), respectively, and the combined specificity of the assay was 89.5% (17/19). The combined positive and negative predictive values of the assay were 99.7% (696/698) and 70.8% (17/24), respectively. Studies were also performed on spiked cultures to establish the specificity and performance sensitivity of the method. Staphylococcus QuickFISH has a turnaround time (TAT) of <30 min and a hands-on time (HOT) of <5 min. The ease and speed of the method have the potential to improve the accuracy of therapeutic intervention by providing S. aureus/CoNS identification simultaneously with Gram stain results.

Publication types

  • Evaluation Study
  • Multicenter Study

MeSH terms

  • Bacteremia / diagnosis*
  • Bacteremia / microbiology
  • Bacteriological Techniques / methods*
  • Blood / microbiology*
  • Humans
  • In Situ Hybridization, Fluorescence / methods*
  • Molecular Diagnostic Techniques / methods*
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Staphylococcal Infections / diagnosis*
  • Staphylococcal Infections / microbiology
  • Staphylococcus / genetics
  • Staphylococcus / isolation & purification*