TABLE 1.
Broth dilution counts of rifampin survivors according to age of initial cultures
| Age of initial culture (days) | No. of turbid tubes observed (dilutions)a | Broth count (cells ml−1)b |
|---|---|---|
| 4 | 1 (100), 0 (10−1), 0 (10−2) | 0.085 |
| 30 | 3 (10−1), 2 (10−2), 0 (10−3) | 85 |
| 100 | 3 (10−2), 2 (10−3), 0 (10−4) | 8.51 × 102 |
a
After exposure to rifampin (100 μg ml−1) for 5 days. These representative results have been confirmed in five independent experiments. Starting culture was 10 ml of 2 × 107 ml−1.
b
Estimated as described by Fisher and Yates (13).