TABLE 2.
Inhibition at 15°C of L. monocytogenes (LM) by competitive-exclusion microorganisms (CEM) in biofilms formed on stainless steel coupons
| CEM strain no. |
L. monocytogenes or CEM (log10 CFU/cm2) at daya:
|
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0
|
7
|
14
|
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 | |
| 141-1 | 3.7 ± 0.1 | 3.7 ± 0.1 | 6.5 ± 0.2 | 8.5 ± 0.4 | <1.7b | 8.1 ± 0.4 | 9.2 ± 0.4 | 5.3 ± 0.1 | 8.2 ± 0.6 | 9.5 ± 0.3 | 6.6 ± 0.3 | 8.8 ± 0.2 |
| 152 | 3.7 ± 0.1 | 3.7 ± 0.1 | 6.3 ± 0.3 | 8.5 ± 0.4 | 1.7 | 7.9 ± 0.3 | 9.2 ± 0.4 | 4.3 ± 0.2 | 8.7 ± 0.3 | 9.5 ± 0.3 | 6.5 ± 0.4 | 8.4 ± 0.4 |
| 375-1 | 3.7 ± 0.1 | 3.7 ± 0.1 | 6.4 ± 0.3 | 8.5 ± 0.4 | 2.7 ± 0.2 | 7.7 ± 0.6 | 9.2 ± 0.4 | 5.3 ± 0.3 | 8.7 ± 0.1 | 9.5 ± 0.3 | 6.6 ± 0.3 | 9.0 ± 0.2 |
| C-1-92 | 3.7 ± 0.1 | 3.7 ± 0.1 | 6.6 ± 0.4 | 8.5 ± 0.4 | <1.7 | 6.7 ± 0.2 | 9.2 ± 0.4 | <1.7 | 8.6 ± 0.3 | 9.5 ± 0.3 | <1.7 | 8.5 ± 0.7 |
| 143-1 | 3.7 ± 0.1 | 3.7 ± 0.1 | 6.5 ± 0.2 | 8.5 ± 0.4 | 4.7 ± 0.4 | 7.7 ± 0.4 | 9.2 ± 0.4 | 2.6 ± 0.1 | 7.8 ± 0.2 | 9.5 ± 0.3 | 6.4 ± 0.2 | 9.0 ± 0.3 |
| C-1-152 | 3.7 ± 0.1 | 3.7 ± 0.1 | 6.3 ± 0.3 | 8.5 ± 0.4 | <1.7 | 7.5 ± 0.2 | 9.2 ± 0.4 | <1.7 | 6.7 ± 0.7 | 9.5 ± 0.3 | <1.7 | 8.3 ± 0.6 |
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).