176-177 / 350
February 20, 2013
40
Figure 2. 3M Petrifilm
Salmonella
vs. FDA-BAM – raw shrimp, bunched spinach, dry dog food (375g)
1
2
Screen for
Indigenous
Salmonella
Matrix
MPN
Add 25g + 225ml Lactose broth,
Spinach
– mix manually, do not blend.
Shrimp & dog food
: blend 2 min and let stand
60±5 min at room temp
Mix and adjust pH to 6.8±0.2 if necessary
24±2h h at 35°C
0.1ml sample +
10ml RV, 24±2h at
42±0.2°C
Estimate
total Aerobic
Counts
High Microbial Load
Products
1.0ml sample + 10ml
TT, 24±2h at
43±0.2°C
Transfer typical colonies to
TSI/LIA slants
24±2h at 35°C
Low Microbial Load
Products
1.0ml sample + 10ml
TT, 24±2h at
35±2°C
BAM
Biochemical/serological confirmation on all
enrichments according to
FDA-BAM
• Streak to XLD & HE - 24±2h at 35°C
• Streak to BS - incubate at 35°C for 24±2h,
read and pick if applicable.
Re-incubate another 24 h
3M
Dry dog food
: 375g+3.375L 3M BPW ISO
Spinach & shrimp
: 25g + 225ml 3M BPW ISO
(prewarmed to 42C)
Homogenize 2 min
18-24h h at 42±1°C
Dog food
Run the 3M Petrifilm
Salmonella Express
System
Transfer typical colonies to
TSI/LIA slants
24±2h at 35°C
Biochemical/serological
confirmation on all
enrichments according to
FDA-BAM
• Streak to XLD & HE - 24±2h at 35°C
• Streak to BS - incubate at 35°C for
24±2h, read and pick if applicable.
Re-incubate another 24 h
Pick typical colony and
transfer to TSI/LIA slants
24±2h at 35°C
Biochemical/serological
confirmation on all
enrichments according to
FDA-BAM
0.1ml sample
+ 10ml RV, 24±2h at
42±0.2°C
1.0ml sample
+ 10ml TT, 24±2h at
35±2°C
Shrimp & Spinach
0.1ml sample
+ 9.9ml RV10
8h at 41.5°C
3
4
5