Table 4.
Relative expression and functional inactivation of genes
| Strain | Genea | Mean fold expression compared with R6b | Gene inactivateda,c | MIC of tetracycline (mg/L)d | MIC of ciprofloxacin (mg/L)d |
|---|---|---|---|---|---|
| R6 | — | — | none | 0.125 | 0.5 |
| patA | — | patA | 0.125 | 0.5 | |
| patB | — | patB | 0.125 | 0.5 | |
| spr0632 | — | spr0632 | 0.125 | 0.5 | |
| tenA | — | tenA | 0.125 | 0.5 | |
| thiD | — | thiD | 0.125 | 0.5 | |
| thiE | — | thiE | 0.125 | 0.5 | |
| R6M1TC-5 | — | — | none | 8 | 4 |
| patA | 6.031 ± 3.647 | patA | 2 | 1 | |
| patB | — | patB | 4 | 1 | |
| spr0632 | 4.334 ± 1.048 | spr0632 | 4 | 4 | |
| tenA | 5.597 ± 0.997 | tenA | 8 | 4 | |
| thiD | 5.165 ± 1.374 | thiD | 8 | 4 | |
| thiE | 3.952 ± 0.880 | thiE | 8 | 4 | |
| spr1021 | 1.685 ± 0.247 | spr1021 | — | — | |
| R6p_patA(R6M1TC)-rpsL+ | — | — | none | 0.25 | — |
| patA | 7.782 ± 1.157 | — | — | — | |
| R6M2TC-4 | — | — | none | 8 | 8 |
| patA | 15.268 ± 5.841 | patA | 2 | 2 | |
| patB | — | patB | 2 | 2 | |
| spr0632 | 8.325 ± 2.587 | spr0632 | 2 | 4 | |
| tenA | 6.616 ± 1.513 | tenA | 2 | 8 | |
| thiD | 6.955 ± 0.541 | thiD | 4 | 8 | |
| thiE | 4.381 ± 0.570 | thiE | — | 8 | |
| spr1021 | 1.548 ± 0.199 | spr1021 | — | — | |
| R6p_patA(R6M1TC)-rpsL+ | — | — | none | 0.25 | — |
| patA | 11.426 ± 3.034 | — | — | — |
aS. pneumoniae R6 gene accessions: patA, spr1887; patB, spr1885; tenA, spr0634; thiD, spr0638; thiE, spr0637.
bMean fold expression was measured using qRT–PCR. Gene expressions were normalized on the 16S rRNA expression. The gene spr1021 was used as a control.
cInactivation of patA and patB was performed as a control.
dThe MICs are the results of three independent biological replicates. MICs in bold are significantly different from the parent strain without the inactivated gene.