Pickering S A W, Bayston R, Scammell B E
Academic Department of Orthopaedic and Fracture Surgery, Queen's Medical Centre, Nottingham, England, UK.
J Bone Joint Surg Br. 2003 May;85(4):588-93. doi: 10.1302/0301-620x.85b4.12644.
Infection of orthopaedic implants is a significant problem, with increased antibiotic resistance of adherent 'biofilm' bacteria causing difficulties in treatment. We have investigated the in vitro effect of a pulsed electromagnetic field (PEMF) on the efficacy of antibiotics in the treatment of infection of implants. Five-day biofilms of Staphylococcus epidermidis were grown on the tips of stainless-steel pegs. They were exposed for 12 hours to varying concentrations of gentamicin or vancomycin in microtitre trays at 37 degrees C and 5% CO2. The test group were exposed to a PEMF. The control tray was not exposed to a PEMF. After exposure to antibiotic the pegs were incubated overnight, before standard plating onto blood agar for colony counting. Exposure to a PEMF increased the effectiveness of gentamicin against the five-day biofilms of Staphylococcus epidermidis. In three of five experiments there was reduction of at least 50% in the minimum biofilm inhibitory concentration. In a fourth experiment there was a two-log difference in colony count at 160 mg/l of gentamicin. Analysis of variance (ANOVA) confirmed an effect by a PEMF on the efficacy of gentamicin which was significant at p < 0.05. There was no significant effect with vancomycin.
骨科植入物感染是一个重大问题，附着在“生物膜”上的细菌对抗生素的耐药性增加，导致治疗困难。我们研究了脉冲电磁场（PEMF）对植入物感染治疗中抗生素疗效的体外影响。在不锈钢钉的尖端培养了5天的表皮葡萄球菌生物膜。将它们在37℃和5%二氧化碳条件下，于微量滴定板中暴露于不同浓度的庆大霉素或万古霉素12小时。试验组暴露于脉冲电磁场。对照板未暴露于脉冲电磁场。暴露于抗生素后，将钉子过夜培养，然后标准接种到血琼脂平板上进行菌落计数。暴露于脉冲电磁场可提高庆大霉素对5天表皮葡萄球菌生物膜的有效性。在五个实验中的三个实验中，最小生物膜抑制浓度至少降低了50%。在第四个实验中，在160mg/l庆大霉素时菌落计数有两个对数差异。方差分析（ANOVA）证实脉冲电磁场对庆大霉素的疗效有影响，p<0.05时具有显著性。万古霉素没有显著影响。
