4. AOACRIMicroMethods-2018Awards

83

C rowley et al .: J ournal of AOAC I nternational V ol . 97, N o . 2, 2014  451

Table 4. Individual collaborator results for queso fresco a (125 g test portions) VIDAS LMX b High–level test portions Low-level test portions

Uninoculated test portions Lab 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 + + + + + + + + + + + + – + + – – – – – + + – + – – – – – – – – – – – – 2 c NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 3 + + + + + + + + + + + + – + + – – – + + – – + + – – – – – – – – – – – – 4 + + + + + + + + + + + + – – – – + – + – + + – + – – – – – – – – – – – – 5 + + + + + + + + + + + + – – + + – – + – – – + + – – – – – – – – – – – – 6 + + + + + + + + + + + + – – + + + – + + – – – – – – – – – – – – – – – – 7 + + + + + + + + + + + + – + – – – + + + – + + + – – – – – – – – – – – – 8 + + + + + + + + + + + + – – + – – + – + + + + + – – – – – – – – – – – – 9 + + + + + + + + + + + + + + + + + – – – – – – – – – – – – – – – – – – – 10 + + + + + + + + + + + + – + + – + + – – + – – + – – – – – – – – – – – – 11 c + + + + + + + + + + + + + + + – – – – – – + – + – – – – – – – – – – – – 12 + + + + + + + + + + + + – + + + + – – + – + + + – – – – – – – – – – – – 13 + + + + + + + + + + + + – – – – – + + + + + – + – – – – – – – – – – – – 14 + + + + + + + + + + + + – – – + + – – + – + – + – – – – – – – – – – – – AOAC 993.12 1 + + + + + + + + + + + + – – – – – + + + + + + + – – – – – – – – – – – – 2 c NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 3 + + + + + + + + + + + + + – – – – + – + – – + + – – – – – – – – – – – – 4 + + + + + + + + + + + + – + – – – + + + + – – + – – – – – – – – – – – – 5 + + + + + + + + + + + + – + + – + – + + – + – + – – – – – – – – – – – – 6 + + + + + + + + + + + + + + – – – + + + – – – – – – – – – – – – – – – – 7 + + + + + + + + + + + + + – – + – + + + – – – – – – – – – – – – – – – – 8 + + + + + + + + + + + + + – + + + + – – + + – – – – – – – – – – – – – – 9 + + + + + + + + + + + + + – – – – + – + – – + – – – – – – – – – – – – – 10 + + + + + + + + + + + + + + – – – + + + – + – – – – – – – – – – – – – – 11 c + + + + + + + + + + + + + d + + e + + + f + f – – + f + + – – + f + e – – – – – + g + g + g 12 + + + + + + + + + + + + + – – – + + – – – + – + – – – – – – – – – – – – 13 + + + + + + + + + + + + + + + + + + – – – – + – – – – – – – – – – – – – 14 + + + + + + + + + + + + – – + – + – – – – + + + – – – – – – – – – – – –

a  + = Listeria spp. were detected in samples; – = Listeria spp. were not detected in sample. b  Results were not used in statistical analysis; NA = not applicable (data not submitted). c  Confirmed results from OXA and ALOA were identical for each test portion.

d  Result reported as L. welshimeri. e  Result reported as L. innocua. f  Result reported as L. grayi. g  Results reported as L. ivanovii.

detected by the VIDAS LMX, 445 were confirmed positive using OXA or ALOA selective agars.

Tables 2C–D, and Figures 2A–D, as supplemental data on the J. AOAC Int. website.

Discussion

ALOA Chromogenic Agar

No negative feedback was reported to the study directors from the collaborating laboratories in regards to the performance of the VIDAS LMX assay or the ALOA chromogenic agar. Many

Confirmatory results obtained from the ALOA chromogenic agar were identical to the results obtained from the OXA agar specified by AOAC 993.12 . Out of a total of 447 positives 03/10/2019