Table 3.

Prevention of biofilm formation by chitosan nanoparticles.

Bacteria	Avg CFU/cm2
	Untreated	ChNP *	ChNP-PL *
L. monocytogenes	9.2 × 106	<50 (>184,000-fold ↓)	<50 (>184,000-fold ↓)
S. aureus	8.7 × 107	8.9 × 106 (9.8-fold ↓)	3.6 × 104 (2400-fold ↓)
P. aeruginosa	1.7 × 107	5.0 × 105 (34-fold ↓)	<50 (>184,000-fold ↓)
S. enterica ser. Enteritidis	1.1 × 107	4.4 × 107 (4-fold ↑)	103 (110,000-fold ↓)
E. coli O157:H7	2.7 × 107	1.2 × 108 (4.4-fold ↑)	<50 (>184,000-fold ↓)
Lm + Sa mixed biofilms
L. monocytogenes	1.9 × 107	<50 (>184,000-fold ↓)	<50 (>184,000-fold ↓)
S. aureus	4.2 × 106	3.8 × 106 (1.1-fold ↓)	1.0 × 104 (420-fold ↓)
Lm + Pa mixed biofilms
L. monocytogenes	8.2 × 107	<50 (>184,000-fold ↓)	<50 (>184,000-fold ↓)
P. aeruginosa	4.0 × 107	1.0 × 103 (40,000-fold ↓)	<50 (>184,000-fold ↓)

* ↑- fold increase or ↓-fold decrease in bacterial counts relative to untreated control.