Comparison of the intensity of biofilm formation by Listeria monocytogenes using classical culture-based method and digital droplet PCR

AMB Express

Table 5 Classification of tested L. monocytogenes rods depending on the biofilm formation ability on the polypropylene surface based on the number of copies of the hlyA gene assessed by droplet digital PCR

Intensity of biofilm formation by L. monocytogenes	Number of copies gene hlyA [log n.g.c^a]	Number of strains depending on the origin [n (%)]		p value	Total n = 96
Intensity of biofilm formation by L. monocytogenes	Number of copies gene hlyA [log n.g.c^a]	Clinical strains n = 58	Environmental strains n = 38	p value	Total n = 96
Weak	4.53–4.92	19 (32.8)	5 (13.2)	p < 0.001	24 (25.0)
Moderate	4.93–5.29	16 (27.6)	8 (21.1)	0.284	24 (25.0)
Strong	5.30-5.59	14 (24.1)	10 (26.3)	0.720	24 (25.0)
Very strong	5.60–6.40	9 (15.5)	15 (39.5)	p < 0.001	24 (25.0)