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Table 2 Time to positive signal from retrospectively analysed blood cultures containing gram-positive cocci

From: Rapid identification of pneumococci, enterococci, beta-haemolytic streptococci and S. aureusfrom positive blood cultures enabling early reports

 

Cut-off

Sensitivity (%)

Specificity (%)

Positive predictive value (%)

Negative predictive value (%)

S. aureus vs. CoNS, cut off time points

≤7 h

9

100

100

63

≤23 h

86

59

58

87

β-haemolytic, pneumococci and enterococci vs. viridians group

≤6 h

9

100

100

14

 

≤21 h

94

50

94

50

  1. Consecutive patient blood cultures (n = 360) from a 3 month period were analysed according to time to positive signal (incubation time until positive growth signal), using cut-off time points suggested by Martínez et al. [16] with the modification that enterococci were included in the fast-growing group of streptococci. This analysis was performed in order to evaluate the utility of time to positive signal in the identification process.