TABLE 1.
Listeria sp. counts for floor drain samples collected before and after CE treatment
| Time | Location |
Listeria sp. count (log10 CFU/100 cm2) for floor drainsa |
|||||
|---|---|---|---|---|---|---|---|
| Drain 1 | Drain 3 | Drain 4 | Drain 6 | Drain 8 | Drain 2 (control)b | ||
| Before CE treatmentc | Bottom side of cover | 3.3 ± 0.8 | 4.2 ± 1.2 | 4.2 ± 1.1 | 4.2 ± 1.2 | 7.6 ± 1.1 | 4.2 ± 1.1 |
| Right side of drain | 3.9 ± 0.7 | 5.0 ± 0.9 | 4.3 ± 0.8 | 3.5 ± 1.9 | 7.6 ± 0.8 | 4.6 ± 0.7 | |
| Left side of drain | 4.0 ± 1.0 | 4.4 ± 1.3 | 3.4 ± 1.1 | 3.2 ± 1.5 | 8.2 ± 0.5 | 4.1 ± 0.6 | |
| Inside of drain | 3.5 ± 0.8 | 5.4 ± 1.3 | 4.5 ± 1.1 | 3.6 ± 1.3 | 7.8 ± 0.9 | 5.4 ± 1.4 | |
| Floor within ca. 30 cm of drain | 3.6 ± 0.9 | 5.3 ± 0.6 | 4.3 ± 1.4 | 3.3 ± 1.3 | 6.1 ± 1.9 | 3.8 ± 1.0 | |
| After CE treatmentd | Bottom side of cover | 1.8 ± 0.4e | 1.9 ± 0.3e | 1.9 ± 0.3e | 2.1 ± 0.4e | 4.0 ± 2.0e | 3.6 ± 0.3f |
| Right side of drain | 2.0 ± 0.5e | 2.1 ± 0.8e | 1.7 ± 0.1e | 1.9 ± 0.7e | 3.9 ± 2.0e | 4.0 ± 0.6f | |
| Left side of drain | 2.0 ± 0.6e | 2.3 ± 0.6e | 2.1 ± 1.2e | 1.9 ± 0.4e | 3.9 ± 2.2e | 4.6 ± 0.7f | |
| Inside of drain | 2.0 ± 0.5e | 2.8 ± 1.4e | 1.7 ± 0.1e | 2.0 ± 0.7e | 3.7 ± 1.8e | 5.5 ± 1.2f | |
| Floor within ca. 30 cm of drain | 1.9 ± 0.5e | 2.1 ± 0.6e | 2.1 ± 0.9e | 1.9 ± 0.6e | 3.5 ± 0.8e | 4.1 ± 1.5f | |
The temperatures at drains 1, 3, 4, 6, 8, and 2 were 16.8 ± 2.6, 15.1 ± 2.3, 2.8 ± 1.2, 3.8 ± 1.1, 26.1 ± 1.2, and 11.5 ± 2.7°C (means ± standard deviations), respectively.
This drain served as the control and was not treated with CE.
Each drain was sampled in four locations and assayed for Listeria sp. every 2 weeks for 10 weeks before CE treatment. The values are the means ± standard deviations for six samplings.
Each drain was sampled in four locations and assayed for Listeria sp. every week for 5 weeks following CE treatment. The values are the means ± standard deviations for five samplings.
The Listeria sp. counts in drains after CE treatment were significantly different (P < 0.05) than the Listeria sp. counts in drains before CE treatment.
The Listeria sp. counts in drains after CE treatment were not significantly different (P > 0.05) than the Listeria sp. counts in drains before CE treatment.