Table
4.
Results
by agar medium
BGS = brilliant green sulfa
agar;
BS = bismuth sulfite agar;
DMLIA = douþle-modified lysine iron
agar;
HE = Hektoen enteric agar
TSA
=
tryptic soy agar; XLD =
xylose
lysine deoxycholate agar;
XLT-4 = xylose lysine terg¡tol agar.
vulgaris
produced
colonies on
XLl--4
agar.
'lhe
remaining
cases
of'no
grorvth
appeared
to
be
random
rvith
respecl
to
strain
and
medium,
A
total
of
691
analyses
ri'ere pelfbrnred on
exclusive
strains.
Collaboralor
l6
r'eported
positive
results
on six
of
seven
plates
sh'eaked
wifh
the
E.
cloacae
cultule.'rhe
renraining
agar.
1'SA,
rvas reported
to
have
no
growth. Collaboratol
16
leporled that the
six
pìates
all
contained
growth rvith
colonies
of
a
Salnonel/a-like
appearance.
It
is
concluded
that
this
culture
becarne
contaminated at some
point during
preparation
or
analysis and therefore
these
data rvere eliminated
from
the
statistical analysis. Otl
685
remainìng
analyses,
661
produced
negative results fbr'¿ìccuracy
rvith exclusive
strains
of
96.5%.
A surnrlarl,
ollesults
b¡'agar
mediunr
is
shorvn
in
Table
4.
The
pÈr'centage
of correct lesults
rvas
very similar fbr all
seven
media,
ranging
liorr
97.6 to
98.99'o.
Discussion
ln
this multilaboralory
evaluation
of
the
ANSR
Salmonella
îcst
lor
iclentilìoation
of
presunrplive
S¿tlntonella
spp.
isolates
lì'om
agar media,
the
method
exhibited
exceptional
accuracy
u'ith
inclusive
strains and
a
high
degree
ofexclusivity
rvith non-
salmonellac.
Of the
l8
laboratories
parlicipating
in
the
study,
l5
reporlcd
results
rvith
overall accuracy
of
99
to
100%.'lhere
ilas
orrll'
a
single
fàlse-negative
result out
of
756 Salntonella
spp, colonie
s
testecl.
L}cluding
dtrta
generated
fiom
a
suspected
contarninaled slant
cultur-e,
thele
rvere
24 lalse-positive
results
on non-S.a/äronella
spp.
colonies out of 685 colonies
tested.
All
lÌtt
scven
ofthese
aberr'¿¡nt
|esr¡]ts
occurred
in
thlce
laboratories.
[-alroralory
l6
ieported
six
faìse-positive
lcsults
in
addition
to
those
linked
to
the
contaminated
slant culture.
No
fìrrther
inlbrmation is available
fbr
these
sanrples,
cxcept
that
all
six
ANSR
lìuorescenoe
cì,ìrves
\vele
vcr'\'
strong,
t¡'pical
o1'true
positive
results.
I-aboratory
2
repolted six fàlse-positive
results;
MOZ-OLA
81.
,AT,,:
JOUIìNAI, OF,AOAC] INTTJIìN^IIONAL
VOL. 97'
NO. 3.
20I4
835
fbur
olthesc
occurred in
a
single
ANSIì
assa¡'
run
ol'
I
5
sarnples.
All
but one
ofthc
lalsc-positive lesults
shorvcd
at¡"pical,
rveak
lìuorescence
culves, suggestive
of
cross-contarlination drrling
pelfbrurarrce
ol
thc
ANSR
assay.
l-aboratory
l3
reported
fìr'e
fälse-positive
results.
Again. all but
one
ofthese
results
shorved
atypical, u'eak
fluorescence
curves.
Additionally,
rau'
data
received
from this laboratoly
indicated that
one assay
run
was
lepeated
in
total
due
to
extreme aberlant results
(i.e., invalid
assays), suggesting
that the
technician
was
experiencing
dif1ìcult¡, in pcrforming
tlie
assay
correctly.
lncluding
data
fionl
all l8
laboratories
(rvith the
exclusion
of
the
six
suspected contaminated samples
from
laboratory
l6),
accuracy
on inclusive
and
exclusive
stlains
rvas
99.9 and96.5Vô,
respectively. Considering
only
data
fi'om
the
l5
laboratories
rvithout
clusters
of
aben'anl
resr¡lts,
accurac)' on exclusive strains
rvas 98.87ir,
Recommendations
'l'he
ANSR
Salmonella test was
adopted
as
Official
First
Action
status
for
use as a
rapid.
accut'¿ìtc
ad.iunct
or altemative
to
biochenical
testing
for
identification
of
presumptive
Salnonella
spp. isolates.
Acknowledgments
We thank the
folloiving
collaborators
lor
their
paÍicipation
in
this study:
Dorn
Clalk
and l-londo Dammann, Marshfield
lrood
Salèt.v
(Marshlìeld,
Wl)
Jessica
Dyszel and
Matlherv Vross.
Iìichter
International
(Colunrbus.
OIì)
Nicole
Cuthbert and
Brian Kupski, Silliker
(Crete,
Il-)
Joe
Benzinger,
ñlegan
Lìoyle,
and
Jonathan
lìlannera.
Q Laboratories
(Cincinnati, OH)
Eric
S.
Adanls,
John
B.
Barrett.
Mark
E,.
llerang,
Douglas
E.
Cosby,
Nelson
A.
Cox,
Jonathan
G.
Frye,
l,ari
M.
I-liotl.
Charlene
R.
Jackson, Steven
W. Knapp,
and Luanne
L.
Rigsby,
U.S.
Deparlrnent
of
Agriculture,
Agricultural
Research
Set'r,ice
(Athens,
GA)
Robert
Fuller
and Jan'od Van
Brunt,'lyson
Foods (Springdale,
AI{)
[{arroud Alnughaymishi
and
Andrerv Scollon.
I\4ichigan
State
University.
l)epartment
ol
lìood
Science
¿rnd
Human
Nutrition
(East
l.ansing.
MI)
Mr:ìanir:
Corebello and
Erika
Sai.
Iinilever tl.S.
(Fìnglewood
Clifls,
NJ)
[.isa Kuepfer
and
Jill
Stepnitz, Covance
(Ilattle
Creek,
Ml)
Michael
Iìudgens
and
Waltel
Jones.
NPAnal¡'tical
L"abolatories
(St.
Louis,
MO)
Douglas Waltman
and Selena
York, Georgia Poultry
Laboratory
(Oakrvood,
CA)
Jake Cannon.
Benjamin
l-lorvard, and
Neil
lìognran.
Clertifìed
Laboratories
of
the
Midrvest (Bolingbrook,
lL)
Chad
Pidgeon
and
Amy
Quenneville.
Ben
&
Jelry's
(Burlington. V'l-)
Vikas
Gill
and
l-lua \\¡ang. United
States
l--ood
and
Drug
Adrninistration.
Center
lbr
lrood
Safety and
Applied Nutrition
(College
Park,
MD)
Cori
F'lores
and
Priyanivacla
Kulkarni,
Ilenningsen
Foods
(Onaha.
NE)
Medium"
Correct
lvl¡sidentified
Totaf
BGS
lnclusive
Exclusìve
lnclus¡ve
Exclus¡ve
lnclus¡ve
Exclusive
lnclusive
Exclusive
lnclusìve
Exclusive
lnclus¡ve
Exclusive
lnclusive
Exclu
sive
lnclus¡ve
Exclusive
BS
DMLIA
HE
TSA
XLD
XLT-4
Total
108
98
108
99
108
93
107
100
108
101
108
101
108
69
661
0
5
0
4
0
3
1
4
0
3
0
3
0
2
1
24
108
103
108
103
108
vö
'108
'104
108
104
108
104
108
71
756
685