ERP Micro December 2019

Table 2019.1A . Summary of results for the detection of Listeria in full-cream goat milk cottage cheese (8.4% Fat) Method a GENE-UP ® Listeria spp. 2 (LIS 2)

Extraction Method Inoculation Level

Non-inoculated

Low

High

Candidate Presumptive Positive/ Total # of Samples Analyzed Candidate Presumptive LPOD (CP)

3/120

92/120

120/120

0.03 (0.01, 0.08) 0.13 (0.12, 0.17) 0.08 (0.05, 0.15) 0.16 (0.14, 0.20)

0.77 (0.60, 0.94) 0.32 (0.28, 0.37) 0.29 (0.20, 0.48) 0.43 (0.37, 0.53)

1.00 (0.97, 1.00) 0.00 (0.00, 0.17) 0.00 (0.00, 0.17) 0.00 (0.00, 0.24)

s r b s L c s R d

P Value e

0.0001

0.0000

1.0000

Candidate Confirmed Positive/ Total # of Samples Analyzed Candidate Confirmed LPOD (CC)

2/120

90/120

120/120

0.02 (0.00, 0.06) 0.12 (0.11, 0.17) 0.05 (0.02, 0.09) 0.13 (0.12, 0.16)

0.75 (0.59, 0.91) 0.34 (0.30, 0.39) 0.28 (0.18, 0.46) 0.44 (0.38, 0.53)

1.00 (0.97, 1.00) 0.00 (0.00, 0.17) 0.00 (0.00, 0.17) 0.00 (0.00, 0.24)

s r

s L s R

P Value

0.0123

0.0000

1.0000

Candidate Confirmed Positive/ Total # of Samples Analyzed Candidate Presumptive Positive that Confirmed LPOD (C)

2/120

90/120

120/120

0.02 (0.00, 0.06)

0.75 (0.59, 0.91)

1.00 (0.97, 1.00)

s r

0.12 (0.11, 0.17) 0.05 (0.02, 0.09) 0.13 (0.12, 0.16)

0.34 (0.30, 0.39) 0.28 (0.18, 0.46) 0.44 (0.38, 0.53)

0.00 (0.00, 0.17) 0.00 (0.00, 0.17) 0.00 (0.00, 0.24)

s L s R

P Value

0.0123

0.0000

1.0000

Positive Reference Samples/ Total # of Samples Analyzed

4/120

99/120

120/120

Reference LPOD

0.03 (0.01, 0.08) 0.17 (0.15, 0.20) 0.06 (0.02, 0.13) 0.18 (0.16, 0.22)

0.83 (0.66, 0.99) 0.26 (0.23, 0.30) 0.29 (0.20, 0.47) 0.39 (0.33, 0.53)

1.00 (0.97, 1.00) 0.00 (0.00, 0.17) 0.00 (0.00, 0.17) 0.00 (0.00, 0.24)

s r

s L s R

P Value

0.0199

0.0000

1.0000

dLPOD (Candidate vs. Reference) f dLPOD (Candidate Presumptive vs. Candidate Confirmed) f

-0.02 (-0.07, 0.03)

-0.08 (-0.31, 0.16)

0.00 (-0.03, 0.03)

0.01 (-0.04, 0.06) 0.00 (-0.03, 0.03) a Results include 95% Confidence Intervals, b Repeatability Standard Deviation, c Among-Laboratory Standard Deviation, d Reproducibility Standard Deviation, e P Value = Homogeneity test of laboratory PODs; f A confidence interval for dLPOD that does not contain the value 0 indicates a statistically significant difference between the two methods 0.02 (-0.22, 0.25)

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