Increasing incidence of multi-drug resistant bacterial pathogens, especially in clinical settings, has been developed into a grave health situation. The drug resistance problem demands the necessity for alternative unique therapeutic policies. One such tactic is targeting the quorum sensing (QS) controlled virulence and biofilm production. In this study, we evaluated a marine steroid Siphonocholin (Syph-1) isolated from Siphonochalina siphonella against Chromobacterium violaceum (CV) 12472, Pseudomonas aeruginosa (PAO1), Methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii (BAA) for biofilm and pellicle formation inhibition, and anti-QS property. MIC of Syph-1 against MRSA, CV, PAO1 was found as 64 µg/mL and 256 µg/mL against BAA. At selected sub-MICs, Syph-1 significantly (P ≤ 0.05) decreased the production of QS regulated virulence functions of CV12472 (violacein) and PAO1 [elastase, total protease, pyocyanin, chitinase, exopolysaccharides, and swarming motility]. The Syph-1 significantly decreased (p = 0.005) biofilm formation ability of tested bacterial pathogens, at sub-MIC level (PAO1 > MRSA > CV > BAA) and pellicle formation in A. baumannii (at 128 µg/mL). Molecular docking and simulation results indicated that Siph-1 was bound at the active site of BfmR N-terminal domain with high affinity. This study highlights the anti-QS and anti-biofilm activity of Syph-1 against bacterial pathogens reflecting its broad spectrum anti-infective potential.

尤其在临床环境中，多药耐药细菌病原体的发病率上升已发展为严重的健康状况。耐药性问题需要替代性独特治疗策略的必要性。一种这样的策略是针对群体感应（QS）控制的毒力和生物膜生产。在这项研究中，我们评价船用类固醇从分离Siphonocholin（SYPH-1）Siphonochalina针对siphonella紫色色杆菌（CV）12472，铜绿假单胞菌（PAO1），耐甲氧西林金黄色葡萄球菌（MRSA）和鲍曼不动杆菌（BAA）用于抑制生物膜和防护膜的形成以及抗QS性能。Syph-1对MRSA，CV，PAO1的MIC为64 µg / mL，对BAA为256 µg / mL。在选定的亚MIC，Syph-1（P≤0.05）显着降低了CV12472（紫丁香素）和PAO1的QS调节毒力功能的产生[弹性蛋白酶，总蛋白酶，绿脓素，几丁质酶，胞外多糖和成群运动]。在亚MIC水平（PAO1> MRSA> CV> BAA）和鲍曼不动杆菌（128 µg / mL）中，Syph-1显着降低了测试细菌病原体的生物膜形成能力（p = 0.005）。分子对接和模拟结果表明，Siph-1以高亲和力结合在BfmR N末端域的活性位点。