NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Kent Ridge 117576, Singapore.
NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Kent Ridge 117576, Singapore; Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge 117576, Singapore.
Biomaterials. 2014 Sep;35(27):7690-8. doi: 10.1016/j.biomaterials.2014.05.069. Epub 2014 Jun 14.
Treatment of biofilm-related infections in orthopedics remains a serious clinical challenge. It is known that an electric current can significantly enhance the potency of some antibiotics against biofilms (bioelectric effect) but the uncertainty of the mechanisms and the electrolytic cell-like system used in previous studies limit its applications. Herein, the behavior of Staphylococcus aureus (S. aureus) on an electrically conductive polypyrrole/chitosan film upon passage of a direct current (DC) through the film was investigated in the absence and presence of gentamicin. The killing efficacy of the bacteria within the biofilm by gentamicin was greatly enhanced by the DC treatment. From an analysis of the gene expression by the biofilm bacteria after treatment with gentamicin, DC and their combination, it is postulated that the promotion of bacterial autolysis by DC treatment is responsible for the enhanced susceptibility of biofilm S. aureus to gentamicin. This postulate is supported by an increase in the amount of extracellular deoxyribonucleic acid and adenosine triphosphate, and the appearance of disrupted bacterial cells in the biofilm after DC treatment. These findings provide a new insight into the interaction between DC and bacteria, and offer potential benefits for the treatment of infections in orthopedics.
在骨科领域，治疗生物膜相关感染仍然是一个严峻的临床挑战。已知电流可以显著增强某些抗生素对生物膜的效力（生物电效应），但由于先前研究中使用的机制和电解池样系统存在不确定性，限制了其应用。在此，研究了在不存在和存在庆大霉素的情况下，直流（DC）通过导电聚吡咯/壳聚糖膜时金黄色葡萄球菌（S. aureus）在膜上的行为。DC 处理大大增强了生物膜内细菌对庆大霉素的杀菌效果。通过对生物膜细菌在庆大霉素、DC 及其组合处理后的基因表达进行分析，推测 DC 处理促进细菌自溶是生物膜金黄色葡萄球菌对庆大霉素敏感性增强的原因。这一假设得到了生物膜中细胞外脱氧核糖核酸和三磷酸腺苷含量增加以及 DC 处理后细菌细胞破裂的证据的支持。这些发现为 DC 与细菌相互作用提供了新的见解，并为骨科感染的治疗带来了潜在的益处。
