Table 1
Comparison of the results of the VIDAS ICE with the Dynabeads anti-E. coli
O157 procedure (reference method) concerning the isolation of Shiga toxinproducing
Escherichia coli O157 from samples of faeces and meat onto
sorbitol–MacConkey agar with cefixime (0.05 mg l−1) and tellurite (2.5 mg l−1)
(CT-SMAC)
Sample Origin Total
no. of
samples
IMS a/CT-SMAC VIDAS ICE/
CT-SMAC
Positive Negative Falsenegative
“Falsepositive”
b
Faeces Petting zoo c 95 0 95 0 1
Petting zoo d 73 15 58 2 1
Frozen e 144 11 133 4 2
Sheep
slaughterhouse f
325 5 320 4 0
Total 637 31 606 10 4
Meat Sheep
slaughterhouse g
325 0 325 0 2
Frozen h 35 1 34 0 0
Total 360 1 359 0 2
a IMS, immunomagnetic separation with Dynabeads anti-E. coli O157.
b “False-positive” means in this case true-positive, because the target
bacterium is being isolated.
c Droppings taken from the ground.
d Individual sampling (rectal palpation) living animals.
e Diverse origin (droppings and faeces from individually sampled animals);
all 144 samples were found positive in a previous study, stored at −20 °C and
after some years examined again.
f Rectal contents from sheep, sampled individually at the slaughterline.
g Swab of a sheep carcass, sampled individually immediately after entrance in
the cooling room.
h All 35 samples were found positive in a previous study, stored at −20 °C and
after some years examined again.