TABLE 2.
Number of putative mutants derived from in vitro random mutagenesis of the periplasmic domain of AcrB
| Targeted AcrB region | Selection drug and concn (μg/ml)a | No. of mutants |
||||
|---|---|---|---|---|---|---|
| Plated | Selected overnight | MIC tested | Showing ≥4-fold decreased EPI efficacyb | Sequenced | ||
| Periplasmic loop 1 (residues 29–330) | NMP 100 + LZD 90 | 1.2 × 105 | 139 | 139 | 124 | 38c |
| NMP 100 + LZD 128 | 4 × 104 | |||||
| NMP 100 + CHL 8 | 5 × 104 | 24 | 21 | 5 | 5 | |
| PAβN 25 + NOV 16 | 6 × 104 | |||||
| PAβN 25 + CLR 16 | 8 × 104 | 34 | 34 | |||
| Periplasmic loop 2 (residues 561–862) | NMP 100 + LZD 90 | 1.1 × 105 | 2 | 2 | 2 | 2 |
| NMP 100 + CHL 8 | 6 × 104 | |||||
| PAβN 25 + NOV 16 | 1.1 × 105 | |||||
| PAβN 25 + CLR 16 | 3 × 105 | 450 | 183d | |||
a
LZD, linezolid; CHL, chloramphenicol; NOV, novobiocin; CLR, clarithromycin.
b
With at least one drug.
c
Mutants revealing NMP efficacy reduced ≥4-fold with at least 3 drugs or ≥8-fold with at least one drug.
d
A strain was selected for MIC testing if large colonies on CLR 16/PAβN 25 plates and/or colonies growing on 0.25 μg/ml rifampin in the presence of PAβN were observed.