Table 1.
Locations/names of the floor drain samples and bacterial log reductions in mixed biofilms after 300 ppm QAC treatment.
| Plant | A | B | O157 only | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Drain location | Cooler 1 | Cooler 2 | Hotbox 1 | Hotbox 2 | Cooler 1 | Cooler 2 | Hotbox 1 | Hotbox 2 | |
| Sample name | A-C1 | A-C2 | A-H1 | A-H2 | B-C1 | B-C2 | B-H1 | B-H2 | |
| Biofilml log reductiona | 1.5 (0.1) | 1.6 (0.2) | 1.5 (0.2) | 2.0 (0.1) | 1.8 (0.1) | 3.0 (0.2) | 1.3 (0.1) | 1.6 (0.4) | |
| O157 log reductionb | −0.2 (0.1) | 1.5 (0.7) | 1.0 (0.6) | 2.6 (0.5) | 2.2 (0.6) | 2.4 (0.6) | 2.7 (0.5) | 3.2 (0.4) | 3.4 (0.4) |
aLog reduction (log10 CFU/chip ± SD) of total bacterial counts after 300 ppm QAC treatment in mixed biofilms by environmental microorganisms collected from floor drains.
bLog reduction (log10 CFU/chip ± SD) of viable E. coli O157:H7 cells after 300 ppm QAC treatment in mixed biofilms by environmental microorganisms collected from floor drains, or in E. coli O157:H7 single-strain biofilm.