TABLE 2.
Accumulation of antibiotics in macrophages incubated for 24 h with the concentrations of antibiotics indicated (these concentrations correspond to the Cmax value as defined in except for those for azithromycin and telithromycin)
| Antibiotic | Extracellular concn (mg/liter) | Cellular-to-extracellular concn ratioa
|
|
|---|---|---|---|
| Noninfected cells | Infected cells | ||
| Gentamicin | 18 | 6.3 ± 0.7 | 6.8 ± 1.7 |
| Azithromycin | 10 | 45.0 ± 5.1 | 50.0 ± 7.5 |
| Telithromycin | 6 | 8.6 ± 1.2 | 8.7 ± 1.1 |
| Ciprofloxacin | 4.3 | 3.2 ± 0.6 | 3.2 ± 0.3 |
| Moxifloxacin | 4 | 11.4 ± 0.8 | 13.4 ± 0.4 |
| Oritavancin | 25 | 336.3 ± 13.6 | 343.8 ± 10.6 |
a
Calculated from the determinations of the drug content per milligram of cell protein and using a conversion factor of 3.8 μl/mg of cell protein. All values are means of three determinations ± SD. In statistical analysis (Student's t test), all differences between infected and uninfected cells were nonsignificant (P > 0.05) except those seen with moxifloxacin, for which the P value was 0.02.