Increasing antimicrobial resistance among Staphylococcus aureus necessitates a new antimicrobial with a different site of action. We have isolated a novel cyclic peptide-1 (ASP-1) from Bacillus subtilis with potent activity against methicillin-resistant S. aureus (MRSA) at a minimum inhibitory concentration (MIC) of 8–64 μg/ml. Scanning electron micrographs demonstrated drastic changes in the cellular architecture of ASP-1 treated cells of S. aureus ATCC 29213 and an MRSA clinical isolate at MICs, with damages to the cell wall, membrane lysis and probable leakage of cytoplasmic contents at minimum bactericidal concentrations. The ultrastructure alterations induced by ASP-1 have also been compared with those of oxacillin-treated MRSA cells at its MIC using scanning electron microscopy.

增加金黄色葡萄球菌的抗菌素耐药性需要一种具有不同作用位点的新抗菌剂。我们从枯草芽孢 杆菌中分离出一种新的环状肽-1 (ASP-1)，在最小抑制浓度 (MIC) 为 8–64 μg/ml时对耐甲氧西林金黄色葡萄球菌(MRSA)具有有效活性。扫描电子显微照片显示 ASP-1 处理的金黄色葡萄球菌 细胞的细胞结构发生了巨大变化ATCC 29213 和 MIC 的 MRSA 临床分离物，在最低杀菌浓度下会损坏细胞壁、膜溶解和细胞质内容物可能泄漏。ASP-1 诱导的超微结构改变也与苯唑西林处理的 MRSA 细胞的 MIC 使用扫描电子显微镜进行了比较。