Sader Helio S, Rhomberg Paul R, Jones Ronald N
JMI Laboratories, 345 Beaver Kreek Centre, North Liberty, IA 52317, USA.
Antimicrob Agents Chemother. 2009 Jul;53(7):3162-5. doi: 10.1128/AAC.00093-09. Epub 2009 Apr 27.
Vancomycin and daptomycin MIC results for 1,800 randomly selected oxacillin (methicillin [meticillin])-resistant Staphylococcus aureus (MRSA) bloodstream isolates from nine U.S. hospitals (collected from 2002 to 2006) were determined by a reference broth microdilution (BMD) method using frozen-form panels with precise incremental dilutions and by the Etest technique. The Etest provided vancomycin and daptomycin MIC results that were consistently higher (0.5 to 1.5 log(2) dilution steps) than those provided by the reference BMD method. The dominant MRSA population (91.2% of MRSA isolates) would be categorized as vancomycin nonsusceptible by the MIC results from the Etest method if the susceptibility breakpoint was adjusted downward to < or =1 microg/ml, as suggested by clinical outcome studies.
采用参考肉汤微量稀释（BMD）法，使用具有精确递增稀释度的冷冻板，以及Etest技术，对从美国9家医院随机选取的1800株耐苯唑西林（甲氧西林[美替西林]）金黄色葡萄球菌（MRSA）血流分离株（于2002年至2006年收集）进行了万古霉素和达托霉素的最低抑菌浓度（MIC）检测。Etest法得出的万古霉素和达托霉素MIC结果始终比参考BMD法得出的结果高（0.5至1.5个log(2)稀释步骤）。如果按照临床结果研究的建议，将药敏折点下调至≤1微克/毫升，那么根据Etest法的MIC结果，主要的MRSA群体（占MRSA分离株的91.2%）将被归类为对万古霉素不敏感。
