Bactericidal Effects of 405 nm Light Exposure Demonstrated by Inactivation of Escherichia, Salmonella, Shigella, Listeria, and Mycobacterium Species in Liquid Suspensions and on Exposed Surfaces
Table 3
Inactivation of bacteria aerosolised onto PVC and acrylic surfaces upon exposure to 110 mW cm–2 of high-intensity 405 nm light.
S. enterica (Log10 CFU/plate ± SD)
L. monocytogenes (Log10 CFU/plate ± SD)
Surface material
Exposure time (min)
Dose J (cm)
Non-exposed
Light exposed
Log10 reduction (% reduction)
Non-exposed
Light exposed
Log10 reduction (% reduction)
PVC
2.5
15
2.54 (±0.10)
0.53 (±0.21)
2.01* (98%)
2.08 (±0.45)
1.41 (±0.18)
0.68* (78%)
5
30
2.62 (±0.15)
0.72 (±0.40)
1.90* (99%)
1.93 (±0.28)
1.0 (±0.42)
0.93* (86%)
7.5
45
2.19 (±0.03)
0 (±0.0)
2.19* (100%)
1.69 (±0.40)
0.79 (±0.1)
0.90* (90%)
Acrylic
2.5
15
2.76 (±0.13)
1.59 (±0.05)
1.18* (93%)
2.45 (±0.06)
2.21 (±0.22)
0.24 (36%)
5
30
2.42 (±0.16)
1.18 (±0.31)
1.24* (93%)
2.37 (±0.06)
2.15 (±0.12)
0.22 (39%)
7.5
45
2.66 (±0.1)
1.20 (±0.26)
1.46* (96%)
2.24 (±0.10)
2.02 (±0.17)
0.21 (36%)
10
60
2.09 (±0.16)
0.46 (±0.15)
1.63* (98%)
2.18 (±0.16)
1.75 (±0.21)
0.42* (61%)
*Indicates where a light-exposed sample value was statistically significant from a non-exposed control value ( calculated at the 95% confidence interval). SD: standard deviation of averaged results.
