TABLE 3.
Frequency of transformation of S. pneumoniae R6 to evernimicin resistance with rDNA operons from four selected spontaneous mutants and their parent strains at different drug concentrations
| Donor DNA | Time (h) | Transformation frequency at evernimicin concn (μg/ml)a:
|
|||
|---|---|---|---|---|---|
| 0.03 | 0.06 | 0.125 | 0.25 | ||
| ATCC 49619 | 24 | NG | NG | NG | NG |
| 48 | tntc | NG | NG | NG | |
| 72 | tntc | tntc | 1.0 × 10−6 | NG | |
| ATCC 49619-1 | 24 | 6.8 × 10−5 | 1.9 × 10−5 | 2.0 × 10−6 | NG |
| 48 | tntc | 8.6 × 10−5 | 1.7 × 10−5 | 3.0 × 10−6 | |
| 72 | tntc | tntc | 3.7 × 10−5 | 8.0 × 10−6 | |
| ATCC 49619-2 | 24 | 6.7 × 10−5 | 1.9 × 10−5 | 1.0 × 10−6 | NG |
| 48 | tntc | 9.0 × 10−5 | 2.2 × 10−5 | 1.0 × 10−6 | |
| 72 | tntc | tntc | 3.4 × 10−5 | 3.0 × 10−6 | |
| SP#3 | 24 | NG | NG | NG | NG |
| 48 | tntc | 1.0 × 10−6 | NG | NG | |
| 72 | tntc | tntc | NG | NG | |
| SP#3-1 | 24 | 2.0 × 10−4 | 7.6 × 10−5 | 1.3 × 10−5 | NG |
| 48 | tntc | 1.3 × 10−4 | 4.8 × 10−5 | 1.2 × 10−5 | |
| 72 | tntc | tntc | 1.1 × 10−4 | 2.1 × 10−5 | |
| SP#3-2 | 24 | 7.0 × 10−5 | 1.3 × 10−5 | 1.0 × 10−6 | NG |
| 48 | tntc | 8.4 × 10−5 | 1.7 × 10−5 | 2.0 × 10−6 | |
| 72 | tntc | tntc | 2.4 × 10−5 | 4.0 × 10−6 | |
a
Abbreviations: NG, no growth; tntc, too numerous to count.