University of Rhode Island, College of Pharmacy, Kingston, RI, USA Rhode Island Infectious Diseases Research Program, Veterans Affairs Medical Center, Providence, RI, USA.
University of Rhode Island, College of Pharmacy, Kingston, RI, USA Department of Medicine, Warren Alpert Medical School, Brown University, Providence, RI, USA Division of Infectious Diseases, Rhode Island Hospital, Providence, RI, USA.
J Antimicrob Chemother. 2014 Dec;69(12):3263-7. doi: 10.1093/jac/dku281. Epub 2014 Aug 4.
Antimicrobial lock solutions are used for prevention and management of catheter-related bloodstream infections. ML8-X10 (a prototype oil-in-water micro-emulsion based on a novel free fatty acid), vancomycin/heparin and taurolidine/citrate/heparin (Taurolock™-Hep500) lock solutions were tested against biofilm-forming Staphylococcus epidermidis and methicillin-susceptible Staphylococcus aureus.
MICs were tested in neutral broth (pH ~7) and acidified broth (pH 5). In an established in vitro central venous catheter (CVC) lock model, solutions were introduced after 24 h of bacterial growth in a CVC incubated at 37°C. After an additional 8, 24 or 72 h of incubation, saline flush and cut catheter segments were processed for bacterial quantification. The cfu/mL at 0 h was subtracted from cfu/mL at the different timepoints.
The activities of ML8-X10 and taurolidine solutions were enhanced at lower pH (P < 0.05). Against S. epidermidis, ML8-X10 solution demonstrated less activity than taurolidine at 8 h (P < 0.001), but was not significantly different from vancomycin. At 24 h, ML8-X10 solution demonstrated significantly less activity than taurolidine (P < 0.001), but was significantly more active than vancomycin (P < 0.001). Against S. aureus, ML8-X10 solution was less active than taurolidine at 8 and 24 h (P < 0.001 for both), but was similar to vancomycin. At 72 h, all lock solutions reduced colony counts to levels that approached or reached the limit of detection against both strains.
In our in vitro catheter lock model, the novel free fatty acid emulsion demonstrated activity against biofilm-forming staphylococci similar to or greater than that of vancomycin lock solution. Taurolidine was the most active lock solution at 8 and 24 h, with all lock solutions tested demonstrating high activity at 72 h.
抗菌封管液用于预防和治疗导管相关血流感染。ML8-X10（一种基于新型游离脂肪酸的油包水乳剂的原型）、万古霉素/肝素和替考拉宁/柠檬酸盐/肝素（Taurolock™-Hep500）封管液针对生物膜形成表皮葡萄球菌和耐甲氧西林金黄色葡萄球菌进行了测试。
在中性肉汤（pH~7）和酸化肉汤（pH 5）中测试 MIC。在体外已建立的中心静脉导管（CVC）封管模型中，在 37°C 孵育的 CVC 中培养 24 小时后引入溶液。孵育 8、24 或 72 小时后，用生理盐水冲洗并切割导管段进行细菌定量。从不同时间点的 cfu/mL 中减去 0 h 的 cfu/mL。
在较低 pH 时，ML8-X10 和替考拉宁溶液的活性增强（P<0.05）。对于表皮葡萄球菌，与替考拉宁相比，ML8-X10 溶液在 8 小时时活性较低（P<0.001），但与万古霉素无显著差异。在 24 小时时，ML8-X10 溶液的活性明显低于替考拉宁（P<0.001），但明显高于万古霉素（P<0.001）。对于金黄色葡萄球菌，ML8-X10 溶液在 8 和 24 小时时的活性低于替考拉宁（均 P<0.001），但与万古霉素相似。在 72 小时时，所有封管液将菌落计数降低到接近或达到两种菌株的检测极限水平。
在我们的体外导管封管模型中，新型游离脂肪酸乳剂对生物膜形成的葡萄球菌的活性与万古霉素封管液相似或更高。替考拉宁在 8 和 24 小时时是最活跃的封管液，所有测试的封管液在 72 小时时均表现出高活性。
