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
3
Mark Mozola
1
, Oscar Caballero, Nicole Enslin, Preetha Biswas, and Jennifer Rice
4
Neogen Corp., 620 Lesher Place, Lansing, MI 48912
5
1
Corresponding author’s email
: mmozola@neogen.com6
7
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
14
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
1