Table 2.
Fold increase in MIC of trimethoprim, fold increase in growth rate at different time points (OD600) in trimethoprim-containing broth, and percent increase in survival in trimethoprim-containing agar of three QAC-adapted subpopulations (QAC-P1, QAC-P2, and QAC-P3 compared to non-adapted control (NAc) of eight L. monocytogenes strains.
| Listeria monocytogenes Strains | Fold Increase 1 in MIC of Trimethoprim for QAC-P1 ± SE | Fold Increase 2 in Growth (OD600) of QAC-P1 Compared to Non-Adapted Control in Trimethoprim-Containing Broth at Different Time Points | Percentage Increase 3 in Survivals of Trimethoprim-Agar for QAC-P1 ± SE |
|||
|---|---|---|---|---|---|---|
| 10 h | 12 h | 20 h | 24 h | |||
| EGD (Bug600) | 2.0 ± 0.0 a | 1.7 ± 0.5 a | 3.1 ± 0.2 a | 1.4 ± 0.4 a | 1.2 ± 0.2 b | −6.1 ± 3.1 d |
| N1 227 | 1.3 ± 0.3 b | 1.1 ± 0.1 a | 1.1 ± 0.1 b | 1.7 ± 0.2 a | 2.0 ± 0.2 a | 1.2 ± 1.1 c |
| Scott A | 1.3 ± 0.3 b | 1.4 ± 0.1 a | 2.6 ± 0.9 a | 1.0 ± 0.1 b | 1.2 ± 0.1 b | 23.4 ± 4.5 b |
| NRRL B 33109 | 1.5 ± 0.3 b | 1.3 ± 0.4 a | 1.0 ± 0.1 b | 1.1 ± 0.1 b | 1.0 ± 0.0 b | 0.6 ± 2.1 c |
| NRRL B 33155 | 1.3 ± 0.3 b | 1.1 ± 0.1 a | 1.0 ± 0.1 b | 1.0 ± 0.1 b | 1.0 ± 0.0 b | 40.9 ± 4.3 a |
| NRRL B 33157 | 2.5 ± 0.7 a | 1.1 ± 0.1 a | 1.0 ± 0.1 b | 1.0 ± 0.1 b | 1.0 ± 0.0 b | 41.1 ± 4.5 b |
| ATCC 43257 | 2.0 ± 0.0 a | 1.1 ± 0.2 a | 1.1 ± 0.1 b | 1.0 ± 0.1 b | 1.0 ± 0.0 b | 28.7 ± 3.0 b |
| ATCC 19116 | 1.7 ± 0.3 a | 0.5 ± 0.3 b | 0.6 ± 0.2 b | 1.0 ± 0.2 b | 1.2 ± 0.2 b | 16.9 ± 8.7 b |
| Listeria monocytogenes Strains | Fold Increase 1 in MIC of Trimethoprim for QAC-P2 ± SE | Fold Increase 2 in Growth (OD600) of QAC-P2 Compared to Non-Adapted Control in Trimethoprim-Containing Broth at Different Time Points |
Percentage Increase 3 in Survivals of
Trimethoprim-Agar for QAC-P2 ± SE |
|||
| 10 h | 12 h | 20 h | 24 h | |||
| EGD (Bug600) | 2.0 ± 0.4 a | 2.1 ± 0.5 b | 3.9 ± 1.1 a | 4.3 ± 0.2 a | 1.9 ± 1.0 a | 20.7 ± 6.1 a |
| N1 227 | 1.0 ± 0.0 b | 0.9 ± 0.0 c | 0.7 ± 0.1 b | 1.8 ± 0.2 c | 1.7 ± 0.4 a | −5.8 ± 3.6 c |
| Scott A | 1.4 ± 0.3 a | 4.5 ± 0.1 a | 4.8 ± 0.4 a | 2.5 ± 0.0 b | 1.8 ± 0.2 a | 21.9 ± 4.4 a |
| NRRL B 33109 | 1.3 ± 0.3 b | 0.9 ± 0.4 c | 0.9 ± 0.0 b | 0.9 ± 0.0 d | 0.9 ± 0.0 b | 0.70 ± 0.4 b |
| NRRL B 33155 | 2.2 ± 0.2 a | 1.2 ± 0.0 b | 1.2 ± 0.1 b | 1.0 ± 1.0 d | 1.0 ± 0.0 b | 27.1 ± 1.4 a |
| NRRL B 33157 | 2.0 ± 0.0 a | 1.2 ± 0.1 b | 1.1 ± 0.0 b | 0.9 ± 0.0 d | 1.0 ± 0.0 b | 30.9 ± 1.3 a |
| ATCC 43257 | 2.3 ± 0.3 a | 1.3 ± 0.4 b | 1.3 ± 0.4 b | 1.2 ± 0.1 d | 1.0 ± 0.1 b | 33.5 ± 1.2 a |
| ATCC 19116 | 1.8 ± 0.2 a | 3.5 ± 0.8 a | 1.7 ± 0.7 b | 1.1 ± 0.1 d | 1.0 ± 0.0 b | 22.2 ± 5.2 a |
| Listeria monocytogenes Strains | Fold Increase 1 in MIC of Trimethoprim for QAC-P3 ± SE | Fold Increase 2 in Growth (OD600) of QAC-P3 Compared to Non-Adapted Control in Trimethoprim-Containing Broth at Different Time Points |
Percentage Increase 3 in Survivals of
Trimethoprim-Agar for QAC-P3 ± SE |
|||
| 10 h | 12 h | 20 h | 24 h | |||
| EGD (Bug600) | 1.3 ± 0.3 b | 1.5 ± 0.4 a | 2.1 ± 0.8 a | 2.1 ± 0.4 a | 2.3 ± 0.4 a | −9.6 ± 5.5 c |
| N1 227 | 1.4 ± 0.4 a | 1.0 ± 0.0 a | 1.0 ± 0.0 b | 1.2 ± 0.3 a | 1.2 ± 0.1 b | −0.2 ± 0.1 b |
| Scott A | 2.0 ± 0.0 a | 1.1 ± 0.0 a | 1.4 ± 0.3 a | 1.9 ± 0.9 a | 1.2 ± 0.2 b | 27.1 ± 6.7 a |
| NRRL B 33109 | 1.3 ± 0.1 b | 1.0 ± 1.5 a | 1.2 ± 1.7 b | 1.0 ± 0.1 b | 0.9 ± 0.1 b | 2.5 ± 2.3 b |
| NRRL B 33155 | 1.7 ± 0.2 a | 1.2 ± 1.8 a | 1.4 ± 1.6 b | 1.1 ± 0.1 a | 1.0 ± 0.0 b | 32.6 ± 0.9 a |
| NRRL B 33157 | 2.0 ± 0.0 a | 1.0 ± 0.1 a | 1.0 ± 0.0 b | 1.0 ± 0.0 b | 0.9 ± 0.0 b | 35.0 ± 6.1 a |
| ATCC 43257 | 2.0 ± 0.0 a | 1.6 ± 0.9 a | 1.3 ± 0.4 b | 1.1 ± 0.1 a | 1.1 ± 0.1 b | 28.1 ± 2.7 a |
| ATCC 19116 | 2.0 ± 0.0 a | 1.2 ± 0.4 a | 1.2 ± 1.2 b | 1.2 ± 0.1 a | 1.1 ± 0.1 b | 28.2 ± 8.2 a |
a–d Different letters indicate significant differences between means (p < 0.05) by Duncan’s multiple range test for 1 Fold Increase in MIC of Trimethoprim for QAC-Adapted Subpopulations, or 2 Fold Increase in Growth (OD600 nm) of QAC-Adapted Subpopulations Compared to Non-Adapted Control in Trimethoprim-Containing Broth at Different Time Points, or 3 Percentage Increase in Survivals in Trimethoprim-Containing Agar for QAC-Adapted Subpopulations.