Table 2.
Antibiotic susceptibility of S. avermitilis wild type, large-deletion mutants and their transformants carrying resistance gene.
| Minimum Inhibitory Concentration (MIC; μg/mL) * | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| neomycin | ribostamycin | apramycin | streptomycin | spectinomycin | hygromycin B | viomycin † | thiostrepton | lincomycin † | lasalocide | |
| Wild type | < 0.1 | 3.13 | 0.39 | 0.1 | 25 | 6.25 | 0.2 | 0.78 | 25 | 12.5 |
| SUKA5 | < 0.1 | 1.56 | 0.39 | 0.1 | 12.5 | 3.13 | 0.2 | 0.39 | 12.5 | 1.56 |
| SUKA17 | < 0.1 | 1.56 | 0.39 | 0.1 | 12.5 | 3.13 | 0.2 | 0.39 | > 200 | 1.56 |
| SUKA22 ‡ | < 0.1 | 1.56 | 0.39 | 0.1 | 12.5 | 3.13 | 0.2 | 0.39 | > 200 | 1.56 |
| aph(3′) § | 25 | > 200 | 0.39 | 0.1 | 12.5 | 6.25 | 0.2 | 0.39 | 12.5 ¶ | 1.56 |
| aac(3)IV § | 0.78 | 200 | > 100 | 0.1 | 12.5 | 6.25 | 0.2 | 0.39 | 12.5 ¶ | 1.56 |
| aad(3″) § | < 0.1 | 1.56 | 0.39 | 25 | > 200 | 3.13 | 0.2 | 0.39 | 12.5 ¶ | 1.56 |
| hph § | 0.1 | 1.56 | 0.39 | 0.1 | 12.5 | > 200 | 0.2 | 0.39 | 12.5 ¶ | 1.56 |
| vph § | 0.1 | 1.56 | 0.39 | 0.1 | 12.5 | 6.25 | > 100 | 0.39 | 12.5 ¶ | 1.56 |
| tsr § | < 0.1 | 1.56 | 0.39 | 0.1 | 12.5 | 3.13 | 0.2 | > 100 | 12.5 ¶ | 1.56 |
| ermE § | < 0.1 | 1.56 | 0.39 | 0.1 | 12.5 | 3.13 | 0.2 | 0.39 | >200 ¶ | 1.56 |
Spores (ca. 104) were spotted onto YMS agar medium containing designated concentration of antibiotic and grown at 30°C for 3 days.
Viomycin and lincomycin replaced tuberactinomycin N and erythromycin, respectively.
S. avermitilis SUKA22 is isogenic to SUKA17. The left side of the deletion region of SUKA22 (corresponding to 8,886,025–8,925,414 nt in wild-type chromosome) was replaced by a mutant-type loxP sequence to prevent recombination between another wild-type loxP sequence on the right side of the deletion region corresponding to 79,455–1,595,563 nt in the wild-type chromosome.
S. avermitilis SUKA22 carrying aph(3′); aminoglycoside 3′-phosphotransferase gene of Tn5, aac(3)IV; aminoglycoside 3-N-acetyltransferase type IV gene of E. coli, aad(3″); streptomycin 3″-adenylyltransferase gene of E. coli, hph; hygromycin B 7″-phosphotransferase gene of S. hygroscopicus, vph; viomycin phosphotransferase gene of S. vinaceus, tsr; rRNA adenosine-2′-O-methyltransferase gene of S. azureus, and ermE; rRNA aminoadenine-6-N-methyltransferase gene of Saccharomyces erythraea).
The MIC values were obtained from S. avermitilis SUKA5 carrying ermE.