Table 2.
Bacterial counts changes of the three biofilm kinds cultured by methicillin-resistant Staphylococcus aureus after 24 hours of exposure to three antibiotics alone or in combination with linezolid, compared to the viable bacterial counts in biofilm without antibiotic exposure.
| Drugs | Bacterial counts (cfu/mL) | |||||
|---|---|---|---|---|---|---|
| 154311 | 152898 | 159228 | ||||
| Mean | SD | Mean | SD | Mean | SD | |
| No antibiotics | 6.50 | 0.17 | 6.89 | 0.02 | 7.16 | 0.13 |
| LIN 1/8x MIC | 6.48 | 0.12 | 6.88 | 0.03 | 6.71 | 0.22 |
| FOS 1/8x MIC | 6.07 | 0.12 | 6.26 | 0.13 | 7.23 | 0.23 |
| LIN 1/8x MIC + FOS 1/8x MIC | 5.64∗ | 0.09 | 6.14 | 0.33 | 6.75 | 0.50 |
| LIN 1/4x MIC | 6.24 | 0.13 | 6.74 | 0.02 | 6.44∗ | 0.10 |
| FOS 1/4x MIC | 5.14∗ | 0.09 | 6.15 | 0.15 | 7.13 | 0.12 |
| LIN 1/4x MIC + FOS 1/4x MIC | 4.09∗ | 0.22 | 5.97∗ | 0.10 | 6.96 | 0.06 |
| LIN 1/2x MIC | 5.74∗ | 0.14 | 6.39 | 0.05 | 6.20∗ | 0.09 |
| FOS 1/2x MIC | 4.87∗ | 0.08 | 6.28 | 0.06 | 6.75 | 0.30 |
| LIN 1/2x MIC + FOS 1/2x MIC | 1.86∗ | 0.10 | 5.30∗ | 0.09 | 6.40∗ | 0.07 |
| LEV 1/8x MIC | 6.49 | 0.17 | 6.58 | 0.10 | 6.79 | 0.27 |
| LIN 1/8x MIC + LEV 1/8x MIC | 6.20 | 0.24 | 7.12 | 0.17 | 7.20 | 0.26 |
| LEV 1/4x MIC | 6.14 | 0.06 | 6.53 | 0.15 | 7.19 | 0.23 |
| LIN 1/4x MIC + LEV 1/4x MIC | 5.34∗ | 0.08 | 6.50 | 0.11 | 6.87 | 0.27 |
| LEV 1/2x MIC | 6.38 | 0.17 | 6.43 | 0.26 | 7.23 | 0.23 |
| LIN 1/2x MIC + LEV 1/2x MIC | 5.35∗ | 0.12 | 6.56 | 0.12 | 6.42∗ | 0.09 |
| RIF (1 mg/L) | 6.04 | 0.37 | 6.70 | 0.07 | 6.67 | 0.34 |
| LIN 1/8x MIC + RIF (1 mg/L) | 6.30 | 0.14 | 6.78 | 0.09 | 6.84 | 0.25 |
| LIN 1/4x MIC + RIF (1 mg/L) | 5.36∗ | 0.28 | 6.71 | 0.05 | 6.86 | 0.11 |
| LIN 1/2x MIC + RIF (1 mg/L) | 5.50∗ | 0.16 | 6.48 | 0.24 | 6.47∗ | 0.32 |
LIN: linezolid; FOS: fosfomycin; LEV: levofloxacin; RIF: rifampin
Data are shown as means ± standard deviations. An asterisk (∗) indicates significant difference P < 0.05.