Table 3. Bactericidal efficacies of Rox500-20 and AFA-PBS-20 at −20°C.
| Solution Type | Bacteria | Bacterial titer log10CFU/ml at different contact times | |||
|---|---|---|---|---|---|
| Control | 3 min | 5 min | 10 min | ||
| Rox500-20a | Escherichia coli | 8.60 ± 0.00 | <2.6 ± 0.00c | <2.6 ± 0.00c | NT |
| Salmonella Infantis | 9.00 ± 0.00 | 5.57 ± 0.09d | <2.6 ± 0.00c | NT | |
| AFA-PBS-20b | E. coli | 8.09 ± 0.40 | NT | 8.09 ± 0.36 | 7.91 ± 0.08 |
| S. Infantis | 8.24 ± 0.39 | NT | 8.24 ± 0.05 | 8.18 ± 0.28 | |
a QAC-Rontect® was diluted 1:250 with 0.34% FdCa(OH)2 and mixed equally with the anti-freeze agent. b The anti-freeze agent (AFA) mixed with PBS in equal amount as AFA-PBS-20. c Undetectable level, when <2.6 log10 colony forming unit (CFU/ml). d Effective bacterial inactivation (≥3 log10 (CFU/ml). Data represent means ± SE of 3 different experiments.