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Table 4 Detection of E. sakazakii in inoculated infant formula samples

From: A robotic DNA purification protocol and real-time PCR for the detection of Enterobacter sakazakii in powdered infant formulae

  ATCC 29544 ATCC 51329
   ISO real-time PCR (C T values)   ISO real-time PCR (C T values)
Powdered Infant Formula Seeding level (CFU/25 g)   BPW BPW-mLST Seeding level (CFU/25 g)   BPW BPW-mLST
  0 - - - - - - 0 - - - - - -
  4 +++ 17.68 ± 1.27 19.24 ± 0.26 4.5 +++ 25.75 ± 3.44 23.70 ± 2.09
PIF 1 8.8 +++ 18.95 ± 1.53 19.48 ± 0.20 9.5 +++ 23.40 ± 0.93 24.15 ± 0.72
  18 +++ 20.46 ± 3.36 18.99 ± 0.46 19 +++ 20.78 ± 2.11 22.61 ± 0.27
  100 +++ nd 19.25 ± 0.39 103.5 +++ 21.33 ± 0.57 23.51 ± 1.73
  0 - - - - - - 0 - - - - - -
  4 +++ nd 22.26 ± 0.42 4.5 + - + 33.40 ± 4.14 24.53 ± 1.13*
PIF 2 8.8 +++ nd 21.73 ± 0.39 9.5 +++ 31.99 ± 5.85 25.31 ± 1.83
  18 +++ nd 21.22 ± 0.66 19 +++ 33.46 ± 1.86 26.44 ± 0.62
  100 +++ 20.27 ± 3.77 21.31 ± 0.53 103.5 +++ 32.95 ± 1.19 25.26 ± 2.66
  0 - - - - - - 0 - - - - - -
  0.25 nd nd nd 0.25 nd 24.74 ± 0.41* 22.75 ± 0.32*
  0.375 nd nd nd 0.375 nd 27.40 ± 0.45§ 21.90 ± 0.02§
PIF 3 4 +++ 16.39 ± 0.66 19.69 ± 1.12 4.5 +++ 21.72 ± 0.24 24.43 ± 3.03
  8.8 +++ 19.51 ± 2.44 19.40 ± 0.40 9.5 +++ 21.80 ± 1.61 22.16 ± 1.22
  18 +++ 18.73 ± 0.49 19.42 ± 0.57 19 +++ 21.59 ± 0.96 22.12 ± 1.03
  100 +++ 18.89 ± 0.32 19.29 ± 1.80 103.5 +++ 20.67 ± 0.41 21.71 ± 0.46
  1. C T values are means ± standard deviation for 3 independent experiments. +: detection of E. sakazakii; -: no detection of E. sakazakii; nd: not done; *C T value of 2 out 3 independent experiments analysed in duplicate; §C T value of 1 out 2 experiment analysed in duplicate.