AOAC RI ERP Final Action Recommendations - BOOK

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REVISED 121213
Evaluation of the ANSR® for Salmonella Assay for Identification of Salmonella spp. from 1
Colony Picks from Selective/Differential Agar Media: Collaborative Study 2
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Mark Mozola1, Oscar Caballero, Nicole Enslin, Preetha Biswas, and Jennifer Rice 4
Neogen Corp., 620 Lesher Place, Lansing, MI 48912 5
1 Corresponding author’s email 6
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Collaborators: E.S. Adams, H. Alnughaymishi, J.B. Barrett, J. Benzinger, M.E. Berrang, M. Boyle, J. 8
Cannon, D. Clark, A. Copeland, M. Corebello, D.E. Cosby, N.A. Cox, N. Cuthbert, H. Dammann, J. Dyszel, 9
E. Feldpausch, J. Flannery, C. Flores, J.G. Frye, R. Fuller, V. Gill, L.M. Hiott, B. Howard, M. Hudgens, C.R. 10
Jackson, W. Jones, S.W. Knapp, L. Kuepfer, P. Kulkarni, B. Kupski, C. Pidgeon, A. Quenneville, L.L. Rigsby, 11
N. Rogman, E. Sai, A. Scollon, M. Sisemore, J. Stepnitz, J. Van Brunt, M. Vross, D. Waltman, H. Wang, G. 12
Whitbeck, S. York, L. Zhang 13
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A collaborative study was conducted to evaluate performance of the ANSR® for Salmonella assay for 15
identification of Salmonella spp. from colony picks taken from selective/differential agar media. The 16
ANSR Salmonella assay is an isothermal nucleic acid amplification test based on the nicking enzyme 17
amplification reaction chemistry. The test can be completed in less than 40 minutes including sample 18
preparation. A total of 18 laboratories representing industry, government, academic, and commercial 19
testing laboratories participated in the study. Each collaborator tested up to 84 samples, comprised 20
of colony picks of 6 Salmonella spp. and 6 non-salmonellae taken from 6 selective/differential agar 21
media as well as tryptic soy agar. A total of 1,441 analyses were performed, of which 1,416 gave the 22
correct identification, for overall accuracy of 98.3%. For identification of Salmonella spp., 755 of 756 23
tests (99.9%) produced the correct result. For identification of non-salmonellae as such, 661 of 685 24
assays (96.5%) produced the correct result. Of the 18 laboratories, 15 produced data sets with 99- 25
100% accuracy. The majority of false-positive results were clustered in 3 laboratories; analysis of raw 26
data suggests procedural difficulties in at least 2 cases, which may explain the atypical data from 27
these collaborators. The ANSR Salmonella assay can be used as a rapid, accurate adjunct or 28
alternative to biochemical testing for identification of presumptive Salmonella spp. isolates. 29
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