Table 1.
Antibacterial activity comparison of (a) erythromycin (Ery) against S. aureus (SA) ATCC 25923 cells and the AZB samples against (b) SA (c) MRSA5, and (d) ERSA cells.
| Passages | Fold Change | |||
|---|---|---|---|---|
| (a) Ery/SA | (b) AZB/SA | (c) AZB/MRSA5 | (d) AZB/ERSA | |
| 1 | N.D. | N.D. | N.D. | N.D. |
| 2 | 2 | 2 | 2 | N.D. |
| 3 | 2 | 2 | 2 | N.D. |
| 4 | 4 | 2 | 2 | N.D. |
| 5 | 4 | 2 | 2 | 2 |
| 6 | 4 | 4 | 2 | N.D. |
| 7 | 8 | 4 | 2 | N.D. |
| 8 | 2000 | 4 | 2 | 4 |
| 9 | 20,000 | 4 | 2 | 4 |
| 10 | 20,000 | 4 | 2 | N.D. |
N.D.: not determined; the fold change of MLC (MLCi+1/i, where i is the passage of growth from 1 to 9) for AZB and erythromycin with the pressure of their sub-lethal concentration (0.5 MLC) was calculated. Experiments were performed in triplicates and showed the same results in all experiments.