Recently, opportunistic nosocomial infections caused by Acinetobacter baumannii have become increasingly prevalent worldwide. The pathogen often establishes biofilms that adhere to medical devices, causing chronic infections refractory to antimicrobial therapy. Clinical reports have indicated that some macrolide antibiotics are effective against chronic biofilm-related infections. In this study, we examined the direct anti-biofilm effects of seven macrolides (azithromycin, clarithromycin, erythromycin, josamycin, spiramycin, fidaxomicin, and ivermectin) on A. baumannii using a simple and newly established in vitro assay system for the swift and serial spectrophotometric determinations of two biofilm-amount indexes of viability and biomass. These macrolides were found to possess direct anti-biofilm effects exerting specific anti-biofilm effects not exclusively depending on their bacteriostatic/bactericidal effects. The anti-biofilm effect of azithromycin was found to be the strongest, while those of fidaxomicin and ivermectin were weak and limited. These results provide insights into possible adjunctive chemotherapy with macrolides for A. baumannii infection. Common five macrolides also interfered with the Agrobacterium tumefaciens NTL(pCF218) (pCF372) bioassay system of N-acyl homoserine lactones, providing insights into sample preparation for the bioassay, and putatively suggesting the actions of macrolides as remote signals in bacterial quorum sensing systems.

最近，由鲍曼不动杆菌引起的机会性医院感染在世界范围内变得越来越普遍。病原体通常会形成附着在医疗器械上的生物膜，导致对抗菌治疗无效的慢性感染。临床报告表明，一些大环内酯类抗生素对慢性生物膜相关感染有效。在这项研究中，我们使用一个简单的新建立的体外研究了七种大环内酯类（阿奇霉素、克拉霉素、红霉素、交沙霉素、螺旋霉素、非达霉素和伊维菌素）对鲍曼不动杆菌的直接抗生物膜作用用于快速和连续分光光度法测定两个生物膜数量活力和生物量指标的测定系统。发现这些大环内酯具有直接的抗生物膜作用，发挥特定的抗生物膜作用，而不仅仅取决于它们的抑菌/杀菌作用。发现阿奇霉素的抗生物膜作用最强，而非达霉素和伊维菌素的抗生物膜作用较弱且有限。这些结果为对鲍曼不动杆菌感染的大环内酯类可能的辅助化疗提供了见解。共同5个大环内酯类也干扰了根癌农杆菌NTL（pCF218）（pCF372）生物测定系统Ñ-酰基高丝氨酸内酯，为生物测定的样品制备提供见解，并推测大环内酯类作为细菌群体感应系统中的远程信号的作用。