Table 1.

Detection of Listeria monocytogenes Scott A by the bacteriophage amplification assay using toluidine blue O (TBO) and non ablative laser^* as virucidal agent.

Treatments	Mean counts
	Over 10 cfu/mL	Over 100 cfu/mL
Lambda buffer
C1=Laser 30 J/cm2 for 15 min + cell	3.0 ± 2.12	75.0 ± 35.35
C2=Laser 30 J/cm2 for 15 min + phage	0	0
Skimmed milk
C1=Laser 30 J/cm2 for 15 min + cell	Injurious	Injurious
C2=Laser 30 J/cm2 for 15 min + phage	0	0
Skimmed milk
C1=Laser 14 J/cm2 for 7 min + cell	13.0 ± 2.55	104.0 ± 2.79
C2=Laser 14 J/cm2 for 7 min + phage	0	0
Skimmed milk
C1=Laser 7 J/cm2 for 5 min + cell	12.0 ± 0.46	101.0 ± 6.02
C2=Laser 7 J/cm2 for 5 min + phage	7.0 ± 5.31	7.0 ± 5.44

C₁= cells control; C₂= phage control

Phage title = 2.9 to 5.7 x 10⁸ pfu/mL

^*λ 660ηm, 50mW, 2 mm spot under continuous wave -cw