TABLE 1.

Inhibition at 37°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)a
	0 h			24 h
	LM only	LM + CEM	CEM only	LM only	LM + CEM	CEM only
141-1	2.9 ± 0.1	2.9 ± 0.1	6.5 ± 0.4	7.7 ± 0.2	<1.7b	7.9 ± 0.5
152	2.9 ± 0.1	2.9 ± 0.1	6.6 ± 0.6	7.7 ± 0.5	<1.7	7.8 ± 0.7
143-1	2.9 ± 0.1	2.9 ± 0.1	6.4 ± 0.4	7.7 ± 0.5	<1.7	7.3 ± 0.2
C-1-152	2.9 ± 0.1	2.9 ± 0.1	6.4 ± 0.3	7.7 ± 0.3	<1.7	7.8 ± 0.4
375-1	2.9 ± 0.1	2.9 ± 0.1	6.4 ± 0.5	7.7 ± 0.7	<1.7	8.0 ± 0.5
143-2	2.9 ± 0.1	2.9 ± 0.1	6.5 ± 0.6	7.7 ± 0.4	<1.7	8.0 ± 0.3
141-2	2.9 ± 0.1	2.9 ± 0.1	6.5 ± 0.2	7.7 ± 0.3	<1.7	7.8 ± 0.6
375-2	2.9 ± 0.1	2.9 ± 0.1	6.6 ± 0.5	7.7 ± 0.5	<1.7	7.9 ± 0.4
C-1-92	2.9 ± 0.1	2.9 ± 0.1	6.4 ± 0.3	7.1 ± 0.4	<1.7	7.2 ± 0.5

^aLM 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.

^bMinimum detection limit by direct plating method (<1.7 log₁₀ CFU/cm²).