Department of Microbiology, School of Translational Medicine, University of Manchester School of Medicine, Manchester Royal Infirmary, Manchester, UK.
J Clin Pathol. 2009 Dec;62(12):1112-6. doi: 10.1136/jcp.2009.069021. Epub 2009 Jul 28.
To examine the response of Staphylococcus epidermidis isolates from prosthetic orthopaedic infections to vancomycin concentrations below the minimum inhibitory concentration.
Staphylococcal biofilms were grown in 96-well flat-bottomed cell culture plates under a variety of culture conditions and stained using an ammonium crystal violet solution. Optical density (450 nm wavelength) was recorded to estimate the biofilm density for each strain. Population analysis and time-kill studies were also performed on selected isolates.
A range of responses were observed, including increased biofilm density at drug concentrations approaching the minimum inhibitory concentration. This increased density was associated with the presence of a more resistant population identified on population analysis but without an apparent effect on the time-kill curves.
The ability of some strains to show increased biofilm density could be a factor in the failure of vancomycin therapy reported in some cases. The demonstration that low concentrations of vancomycin may increase the density of newly forming S epidermidis biofilms may indicate an area of potential concern in the use of vancomycin in orthopaedic implants and intravascular catheter locks, and may partially account for some cases of treatment failure.
检测来自人工关节假体感染的表皮葡萄球菌分离株对低于最低抑菌浓度的万古霉素浓度的反应。
在各种培养条件下，将葡萄球菌生物膜在 96 孔平底细胞培养板中生长，并使用氨晶体紫溶液进行染色。记录光密度（450nm 波长）以估计每种菌株的生物膜密度。还对选定的分离株进行了种群分析和时间杀伤研究。
观察到一系列反应，包括在接近最低抑菌浓度的药物浓度下生物膜密度增加。这种增加的密度与种群分析中发现的更耐药种群的存在有关，但对时间杀伤曲线没有明显影响。
一些菌株显示出增加生物膜密度的能力，这可能是报告的一些万古霉素治疗失败的一个因素。低浓度的万古霉素可能会增加新形成的表皮葡萄球菌生物膜的密度，这表明在骨科植入物和血管内导管锁中使用万古霉素可能存在潜在的关注领域，并可能部分解释了一些治疗失败的情况。
