Table 3.
Ultraviolet treatment.
| Ref. | Species | Light Source | Methodology | Log10 Reduction | Inoculation Source | Tolerance |
|---|---|---|---|---|---|---|
| Bacteria | ||||||
| [64] | E. coli | 15 W Hg vapor UV germicidal lamp, 254 nm | 80 cycles | Initially sublethal (increasing 2-fold every 10 cycles) | Cells after irradiation inoculated in fresh LB medium | Yes (resistance) |
| [46] | L. monocytogenes | Xenon flash lamp, spectrum from UV-C to IR | 13 cycles | No data/lethal | Single colony survivors on solid medium plate used for preparation of inoculum for next experimental cycle | No |
| [49] |
E. coli
C. jejuni L. monocytogenes |
Xenon flash lamp, UVC-UV-IR | 20 cycles | Sublethal | Cocktail of strains after PL treatment incubated in fresh medium | Yes (resistance) |
| [65] | E. coli | UVP Chromato-Vue TM-36 transilluminator (UVP Inc., Upland, CA, USA), 302 nm | 60 cycles | Sublethal | LB agar plates with surviving colonies | Yes (resistance) |
| [47] | P. aeruginosa | 4 × xenon flash lamps, white (200–1100 nm) and UV (200–400 nm) light | 1 cycle (2 treatments) |
Sublethal/ lethal |
None | Yes |
| [48] |
L. monocytogenes
L. innocua E. coli |
Xenon flash lamp (SteriPulse system), 200–1100 nm | 10 cycles | No data | Single colony survivors replated on fresh solid medium and used for preparation of inoculum for next cycle | No |
| [44] | L. monocytogenes | SteriPulse-XL RS-3000C (xenon) pulsed light device | 20 cycles | Lethal | TSA + YE plates with single colony survivors used for inoculation | Not stable tolerance (declined after deep-freeze storage) |
| Viruses | ||||||
| [66] | Bacteriophage T7 | UVP® transilluminator (bulbs, UVP 34-0042-01) | 30 cycles | Lethal | A lysate of phage survivors added to a culture of cells and grown to culture lysis | Yes (resistance) |