Use of a surfactant (polysorbate 80) to improve MIC susceptibility testing results for polymyxin B and colistin

摘要: Accurate determination of in vitro activity for polymyxin class agents has consistently been a problem due to their physical-chemical characteristics that can be influenced by the constituents reference and/or standardized susceptibility testing methods. We evaluated impact using polysorbate 80 (P-80), surfactant, broth microdilution (BMD) methods when B and colistin against 247 clinical strains Enterobacteriaceae (124 strains), Acinetobacter spp. (60 Pseudomonas aeruginosa (63 strains). All was performed frozen-form BMD panels with without 0.002% P-80. MIC results both polymyxins were generally 4- 8-fold lower P-80 added compared Mueller-Hinton surfactant. Decreases greatest organisms having values at ≤2 μg/mL among Polymyxins should tested more accurately assess potencies these necessary treat multidrug-resistant Gram-negative bacilli.