Table 3.

Classification of tested L. monocytogenes rods depending on the biofilm formation intensity based on the number of bacteria isolated from the polypropylene surface in a quantitative method

Intensity of biofilm formation by L. monocytogenes	Number of reisolated L. monocytogenes [log CFU × cm−2]	Number of strains depending on the origin [n (%)]		p valuea	Total n = 96
		Clinical strains n = 58	Environmental strains n = 38
Weak	4.26–5.29	19 (31.0)	6 (15.8)	0.011	24 (25.0)
Moderate	5.30–5.91	15 (27.6)	8 (21.1)	0.284	24 (25.0)
Strong	5.92–6.85	13 (22.4)	11 (28.9)	0.293	24 (25.0)
Very strong	6.86–7.97	11 (19.0)	13 (34.2)	0.015	24 (25.0)

Italic values indicate significance of p value (p ≤ 0.05)

^ap value ≤ 0.05