Table 2.

Performance of the method

Application criterionaProbeIsolated microorganismnb SensitivitycSpecificityd
Each assayEUBAll bacteria1820.9481.000
Non-EUBNegative control182NCe NC
Gram-positive chainsSTREP Streptococcus mitis 101.0001.000
STREP Streptococcus pyogenes 3
STREP Streptococcus oralis 1
STREP Streptococcus dysgalactiae 1
STREP Streptococcus sanguis 1
STREP Streptococcus constellatus 1
STREP Streptococcus agalactiae 1
STREP Streptococcus milleri 2
EFAEC Enterococcus faecalis 101.0001.000
Gram-positive clumpsSTAUR Staphylococcus aureus 130.6671.000
Gram-negative rodsECOLI Escherichia coli 231.0001.000
PSEUDAER Pseudomonas aeruginosa 41.0001.000
ENTBAC Klebsiella pneumoniaef 121.0001.000
ENTBAC Serratia marcescensf 4
ENTBAC Proteus mirabilisf 3
ENTBAC Serratia liquefaciensf 2
ENTBAC Enterobacter cloaceaef 2
  • a The application criterion is the micromorphology of the pathogen by the initial Gram staining which is made after the BacT/Alert blood culture system has detected microbial metabolic activity in the blood sample.

  • b n, number of strains positively identified by culturing.

  • c Sensitivity is the proportion of blood samples that contain the target organism (confirmed by culturing) and that give a positive result by FISH analysis.

  • d Specificity is the proportion of blood samples that do not contain the target organism and that give a negative result (confirmed by culturing) by FISH analysis.

  • e NC, not calculated.

  • f Bacterial species identified in addition toEscherichia coli, which is also detected with this probe.