Department of Chemistry, Chemical Biology, and Biomedical Engineering, Charles V. Schaefer School of Engineering and Sciences, Stevens Institute of Technology, Hoboken, NJ 07030, USA.
J Microbiol. 2011 Aug;49(4):663-8. doi: 10.1007/s12275-011-1013-5. Epub 2011 Sep 2.
One of the most important features of bacterial biofilms is their resistance to antibiotics and to the host immune system. In this study, we have found that a small lytic peptide, PTP-7, is very potent to Gram-positive bacteria and is able to kill antibiotic sensitive and resistant Staphylococcus aureus indiscriminately. Further studies have revealed that despite being a cationic peptide, the antibacterial activity of PTP-7 was not affected by the negatively charged extracellular polymeric substance (EPS) of biofilms. PTP-7 could diffuse into the deep layer of S. aureus biofilms to kill bacteria inside biofilms efficiently and effectively. Neither the high concentrations of metal ions nor the acidic pH in biofilms affected the activity of peptide PTP-7. It seems that the unique sequence/structure together with the resistant bacteria killing ability of peptide PTP-7 confers its anti-biofilm activity. This study sheds new light on the treatment of bacterial biofilms, especially various biofilm related infections.
细菌生物膜的一个重要特征是其对抗生素和宿主免疫系统的抵抗力。在这项研究中，我们发现一种小的裂解肽 PTP-7 对革兰氏阳性菌非常有效，能够不分青红皂白地杀死抗生素敏感和耐药的金黄色葡萄球菌。进一步的研究表明，尽管 PTP-7 是一种阳离子肽，但它的抗菌活性不受生物膜中带负电荷的胞外聚合物（EPS）的影响。PTP-7 可以扩散到金黄色葡萄球菌生物膜的深层，有效地杀死生物膜内的细菌。生物膜中高浓度的金属离子和酸性 pH 值都不会影响肽 PTP-7 的活性。似乎肽 PTP-7 的独特序列/结构及其对耐药细菌的杀伤能力赋予了它抗生物膜活性。这项研究为细菌生物膜的治疗，特别是各种与生物膜相关的感染，提供了新的思路。
