TABLE 2.

The change in log₁₀ CFU per milliliter at 4, 24, and 48 h during time-kill experiments with polymyxin B in combination with minocycline against an inoculum of ∼10⁶ CFU/ml of KPC-producing K. pneumoniae clinical isolates^a

^aBactericidal activity (≥3 log₁₀ CFU/ml reduction compared to the initial inoculum) is indicated in bold. Additivity is defined as a reduction of between 1 and 2 log₁₀ CFU/ml and synergy is defined as a reduction of ≥2 log₁₀ CFU/ml caused by the combination compared to the results seen with the most active single agent in the combination. Additivity is highlighted with light gray shading and synergy with dark gray shading. PMB, polymyxin B; MIN, minocycline.