TABLE 3.
Inhibition at 8°C of L. monocytogenes (LM) by competitive-exclusion microorganisms (CEM) in biofilms formed on stainless steel coupons
| CEM strain no. |
L. monocytogenes or CEM count (log10 CFU/cm2) at daya:
|
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0
|
7
|
14
|
21
|
28
|
|||||||||||
| LM only | LM + CEM | CEM only | LM only | LM + CEM | CEM only | LM only | LM + CEM | CEM only | LM only | LM + CEM | CEM only | LM only | LM + CEM | CEM only | |
| 141-1 | 3.7 ± 0.2 | 3.7 ± 0.2 | 6.0 ± 0.4 | 6.8 ± 0.3 | 3.7 ± 0.1 | 7.4 ± 0.4 | 8.5 ± 0.2 | 3.3 ± 0.1 | 8.4 ± 0.3 | 8.5 ± 0.2 | <1.7b | 8.0 ± 0.4 | 8.8 ± 0.3 | <1.7 | 7.7 ± 0.2 |
| 152 | 3.7 ± 0.2 | 3.7 ± 0.2 | 6.4 ± 0.6 | 6.8 ± 0.3 | 3.9 ± 0.2 | 7.5 ± 0.2 | 8.5 ± 0.2 | 3.5 ± 0.3 | 8.2 ± 0.1 | 8.5 ± 0.2 | <1.7 | 7.6 ± 0.2 | 8.8 ± 0.3 | <1.7 | 7.8 ± 0.3 |
| 375-1 | 3.7 ± 0.2 | 3.7 ± 0.2 | 6.5 ± 0.3 | 6.8 ± 0.3 | 3.7 ± 0.2 | 7.6 ± 0.3 | 8.5 ± 0.2 | 3.0 ± 0.2 | 8.5 ± 0.2 | 8.5 ± 0.2 | <1.7 | 7.8 ± 0.2 | 8.8 ± 0.3 | <1.7 | 7.8 ± 0.2 |
| C-1-92 | 3.7 ± 0.2 | 3.7 ± 0.2 | 6.7 ± 0.6 | 6.8 ± 0.3 | <1.7 | 4.7 ± 0.5 | 8.5 ± 0.2 | <1.7 | 6.5 ± 0.1 | 8.5 ± 0.2 | <1.7 | 5.4 ± 0.3 | 8.8 ± 0.3 | <1.7 | 4.7 ± 0.1 |
| 143-1 | 3.7 ± 0.2 | 3.7 ± 0.2 | 6.5 ± 0.2 | 6.8 ± 0.3 | 3.9 ± 0.1 | 7.2 ± 0.3 | 8.5 ± 0.2 | 4.4 ± 0.4 | 8.1 ± 0.3 | 8.5 ± 0.2 | 5.9 ± 0.3 | 7.5 ± 0.3 | 8.8 ± 0.3 | 3.3 ± 0.3 | 7.7 ± 0.6 |
| C-1-152 | 3.7 ± 0.2 | 3.7 ± 0.2 | 6.4 ± 0.5 | 6.8 ± 0.3 | 3.1 ± 0.3 | 7.4 ± 0.3 | 8.5 ± 0.2 | 4.5 ± 0.2 | 8.1 ± 0.2 | 8.5 ± 0.2 | 4.9 ± 0.3 | 7.8 ± 0.2 | 8.8 ± 0.3 | 6.0 ± 0.5 | 7.7 ± 0.3 |
a
LM only, L. monocytogenes count in biofilm in which only L. monocytogenes bacteria were applied to coupons; LM + CEM, L. monocytogenes count in biofilm in which both L. monocytogenes and CEM were applied to coupons; CEM only, competitive-exclusion microorganism count in biofilm in which only CEM were applied to coupons.
b
Minimum detection limit by direct plating method (<1.7 log10 CFU/cm2).