TABLE 1.
Effects of rRNA mutations on susceptibility of E. coli to antibiotics
| Mutationa | MIC (μg/ml)b
|
|||||
|---|---|---|---|---|---|---|
| ERY | EP-001304 | EP-013420 | EP-013159 | TEL | CET | |
| Wild type | 128 | >512 | 32 | 16 | 16 | 8 |
| A2058G | >512 | >512 | >128 | >128 | >128 | >128 |
| U2609C | 128c | >512 | 64 | 16 | 64 | 64 |
a
Wild-type or mutant RNAs were expressed in the TA531 strain of E. coli (3) from plasmid-borne genes that were the single source of rRNA in the cell. Wild-type cells contained plasmid pKK3535 (7), the A2058G mutant contained plasmid pSTL102 (32), and the U2609C mutant contained plasmid pKK3535(2609C) (13).
b
ERY, erythromycin; TEL, telithromycin; CET, cethromycin.
c
The optical density of the U2609C cell culture grown in the presence of 128 μg erythromycin per ml was less than one-third of the density of the wild-type culture grown in the presence of the drug at this concentration.