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Document 1 of 2 – 3M Petrifilm Salmonella Express PTM Study Report
Page 8 of 41
NOTE:
The official document is electronic. Paper copies are uncontrolled.
The recommended size of the sampling area to verify the presence or absence of the pathogen on the surface is 100 cm
2
(10 cm x 10 cm
or 4 in. x 4 in.)
4
. When sampling with a sponge, cover the entire area going in two directions (left to right then up and down).
1.
.
2.
If the environmental sample has a high microbial load (total aerobic colony count of > 10
4
colony forming units/sample), then after
primary enrichment incubation, transfer 0.1 mL of the primary enrichment into 10.0 mL Rappaport-Vassiliadis R10 (R-V R10) Broth.
Incubate at 41.5 ± 1.0°C for 8-24 hours.
Table 1:
Sample Enrichment Protocols
TEST MATRIX
H
IGH
M
ICROBIAL
LOAD
(≥10
4
CFU/
G
)
SAMPLE
SIZE
PRIMARY ENRICHMENT
SECONDARY ENRICHMENT
ENRICHMENT
VOLUME
(
M
L)
Temperature
(±1.0°C)
Enrichment
Time (hr)
ENRICHMENT
MEDIUM
Temperature
(±1.0°C)
Enrichment
Time (hr)
Foods: Raw
Meat, Poultry
25 g
225
41.5
18-24
R-V R10 Broth :
0.1 mL into
10.0 mL
41.5
8-24
Foods:
Seafood and
Fish
25 g
225
R-V R10 Broth :
0.1 mL into
10.0 mL
41.5
8-24
Foods:
Pasteurized
Eggs
100 g
900
Not required for low microbial load foods.
Animal Feed
375 g
3375
Not required for low microbial load foods.