TABLE 2.
Secondary screening of top 20 candidate compounds against E. coli and A. baumanniia
| Treatment |
E. coli |
A. baumannii |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| FeEnt (cm)b | Fc (cm)b | ColB hits/cellc | ColIa hits/cellc | [59Fe]Ent uptaked |
[14C]lactose uptakee |
MIC (μM)f | FeEnt (cm)g | MIC (μM)f | |
| None | 1.5 ± 0.1 | 1.5 ± 0.1 | 1.0 | 1.0 | 1.0 | 1.0 | NA | 1.2 ± 0.1 | NA |
| CCCP | 2.0 ± 0.1 | 1.9 ± 0.1 | 0.1 ± 0.0 | 0.2 ± 0.0 | 0.2 | 0.2 | NT | 1.5 ± 0.1 | NT |
| Baicalein | 1.7 ± 0.1 | 1.7 ± 0.1 | 0.3 ± 0.1 | 0.7 ± 0.0 | 1.0 | 1.0 | — | 1.2 ± 0.1 | — |
| Cadmium acetate | 2.2 ± 0.1 | 2.1 ± 0.4 | 1.1 ± 0.2 | 0.8 ± 0.1 | NT | NT | 512 | 0 | 256 |
| Carbidopa | 1.6 ± 0.1 | 1.6 ± 0.1 | 1.4 ± 0.5 | NT | NT | NT | — | 1.1 ± 0.0 | — |
| Carboplatin | 1.5 ± 0.0 | 1.6 ± 0.0 | 1.1 ± 0.1 | NT | NT | NT | — | 1.1 ± 0.1 | — |
| p-Chloranil | 1.5 ± 0.2 | 1.6 ± 0.1 | 0.7 ± 0.1 | 0.8 ± 0.0 | NT | NT | — | 1.1 ± 0.0 | — |
| Dideoxyscleroin | 1.6 ± 0.1 | 1.7 ± 0.2 | 1.1 ± 0.2 | NT | NT | NT | — | 1.2 ± 0.0 | — |
| Dequalinium-Cl | 1.4 ± 0.1 | 1.6 ± 0.1 | 1.1 ± 0.1 | NT | NT | NT | — | 1.1 ± 0.0 | — |
| Ebselen | 0h | 0h | 0.6 ± 0.1 | 0.8 ± 0.1 | 0.18 | 0.68 | 128 | 0 | 32 |
| Ellagic acid | 1.6 ± 0.1 | 1.4 ± 0.2 | 0.6 ± 0.1 | 0.7 ± 0.1 | NT | NT | — | 1.1 ± 0.0 | 256 |
| 3-Methoxycatechol | 1.5 ± 0.1 | 1.6 ± 0.5 | 0.9 ± 0.3 | NT | NT | NT | — | 1.1 ± 0.0 | — |
| Thimerosal | 0h | 0h | 1.1 ± 0.1 | 1.1 ± 0.1 | 0.2 | 0.2 | 2 | 0 | 1 |
| Zinc pyrithione | 0h | 0h | 0.0 ± 0.0 | 0.5 ± 0.0 | 0.2 | 0.2 | 4 | 0 | 16 |
| 120304 | 1.6 ± 0.1 | 1.6 ± 0.1 | 1.0 ± 0.2 | NT | NT | NT | — | 1.2 ± 0.1 | — |
| ST003142 | 2.7 ± 0.3 | 2.1 ± 0.0 | 0.0 ± 0.0 | 0.7 ± 0.1 | 1.0 | 1.0 | 256 | 1.7 ± 0.4 | 512 |
| ST005540 | 1.6 ± 0.2 | 1.7 ± 0.2 | 1.2 ± 0.2 | 1.2 ± 0.1 | NT | NT | — | 1.1 ± 0.0 | — |
| ST082990 | 0h | 0h | 0.6 ± 0.0 | 0.7 ± 0.0 | 0.44 | 0.74 | 128 | 0 | 16 |
| ST084954 | 0h | 0h | 1.3 ± 0.3 | 1.1 ± 0.1 | 1.0 | 1.0 | 32 | 1.4 ± 0.1 | 256 |
| KUC101887N | 1.4 ± 0.1 | 1.5 ± 0.1 | 1.1 ± 0.3 | NT | NT | NT | — | 1.1 ± 0.1 | — |
| KUC108008N | 1.5 ± 0.0 | 1.6 ± 0.0 | 1.3 ± 0.3 | NT | NT | NT | — | 1.1 ± 0.0 | — |
| KUC108005N | 1.5 ± 0.1 | 1.6 ± 0.1 | 1.0 ± 0.0 | NT | NT | NT | — | 1.1 ± 0.0 | — |
| KUC108013N | 1.5 ± 0.1 | 1.6 ± 0.1 | 1.3 ± 0.3 | NT | NT | NT | — | 1.1 ± 0.0 | — |
NA, not applicable; NT, not tested. —, MIC exceeded 512 μM.
Siderophore nutrition test using MG1655 with 50 μM FeEnt or Fc and a 100 μM concentration of a compound of interest. The data for CCCP derive from siderophore nutrition tests with the proton ionophore included at 15 μM.
Relative inhibition of ColB or ColIa measured by quantitative determination of colicin titer against MG1655 in the absence or presence of the inhibitors, according to S/S0 = e−k (79), with the titer against untreated bacteria set at 1.0. Addition of the compounds alone (diluted from a DMSO stock) caused ≤5% reduction in bacterial viability. The data for CCCP derive from siderophore nutrition tests with CCCP included at 15 μM.
Uptake of [59Fe]Ent, relative to E. coli MG1655. Data for CCCP derive from experiments with CCCP included at 15 μM.
Uptake of [14C]lactose, relative to E. coli MG1655. Data for CCCP derive from experiments with CCCP included at 15 μM.
MIC determined by titration of compounds against MG1655 or 17978 in LB. The noted concentration represents the point at which we observed growth inhibition in a series of serial 2-fold dilutions from 512 to 0.5 μM.
Siderophore nutrition test using 17978 with 50 μM FeEnt and a 100 μM concentration of a compound of interest.
Some compounds completely blocked bacterial growth at 100 μM, but at lower concentrations caused enlarged growth halos in siderophore nutrition tests (Fig. S2).