Table 3. Determination of the half maximal concentration, IC50, for CAM and PA–CAM conjugates, indicating how much of each compound is needed to inhibit the growth of wild-type S. aureus and E. coli cells or E. coli mutants by halfa,b.
| Compound | IC50 (μM) | |||
|---|---|---|---|---|
| WT-S. aureus | WT-E. coli | E. coli (A2058G) | E. coli (A2503C) | |
| CAM | 3.1 ± 0.3 | 6.2 ± 0.5 | 15.5 ± 1.3 | 24.7 ± 2.3 |
| 1 | >200 | >200 | >200 | >200 |
| 2 | 45.3 ± 5.5 | >100 | >100 | >100 |
| 3 | 12.7 ± 1.0 | >150 | >150 | >150 |
| 4 | 4.7 ± 0.5 | 9.4 ± 0.8 | 9.4 ± 1.0 | 9.4 ± 0.9 |
| 5 | 13.7 ± 1.2 | 35.5 ± 3.6 | 32.3 ± 3.0 | 37.1 ± 3.1 |
| 6 | >200 | >200 | >200 | >200 |
| 7 | >200 | >200 | >200 | >200 |
| 8 | >100 | >300 | >300 | >300 |
| 9 | 66.0 ± 4.6 | >200 | >200 | >200 |
aData represent the mean ± SE values obtained from three independently performed experiments, with two replicates per experiment
bE. coli TA531 cells lacking chromosomal rrn alleles, but containing pKK35 plasmids possessing wild-type 23S rRNA displayed a similar IC50 value for each compound, to those of wild-type (WT) E. coli K12 cells.