Department of Surgery, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
Department of Biological and Biomedical Sciences, Rowan University, Glassboro, NJ 08028, USA.
Colloids Surf B Biointerfaces. 2023 Jul;227:113345. doi: 10.1016/j.colsurfb.2023.113345. Epub 2023 May 12.
Staphylococcus epidermidis are common bacteria associated with biofilm related infections on implanted medical devices. Antibiotics are often used in combating such infections, but they may lose their efficacy in the presence of biofilms. Bacterial intracellular nucleotide second messenger signaling plays an important role in biofilm formation, and interference with the nucleotide signaling pathways provides a possible way to control biofilm formation and to increase biofilm susceptibility to antibiotic therapy. This study synthesized small molecule derivates of 4-arylazo-3,5-diamino-1 H-pyrazole (named as SP02 and SP03) and found these molecules inhibited S. epidermidis biofilm formation and induced biofilm dispersal. Analysis of bacterial nucleotide signaling molecules showed that both SP02 and SP03 significantly reduced cyclic dimeric adenosine monophosphate (c-di-AMP) levels in S. epidermidis at doses as low as 25 µM while having significant effects on multiple nucleotides signaling including cyclic dimeric guanosine monophosphate (c-di-GMP), c-di-AMP, and cyclic adenosine monophosphate (cAMP) at high doses (100 µM or greater). We then tethered these small molecules to polyurethane (PU) biomaterial surfaces and investigated biofilm formation on the modified surfaces. Results showed that the modified surfaces significantly inhibited biofilm formation during 24 h and 7-day incubations. The antibiotic ciprofloxacin was used to treat these biofilms and the efficacy of the antibiotic (2 µg/mL) was found to increase from 94.8% on unmodified PU surfaces to > 99.9% on both SP02 and SP03 modified surfaces (>3 log units). Results demonstrated the feasibility of tethering small molecules that interfere with nucleotide signaling onto polymeric biomaterial surfaces and in a way that interrupts biofilm formation and increases antibiotic efficacy for S. epidermidis infections.
表皮葡萄球菌是与植入医疗器械相关生物膜感染有关的常见细菌。抗生素常用于治疗此类感染，但在生物膜存在的情况下，抗生素可能会失去疗效。细菌细胞内核苷酸第二信使信号转导在生物膜形成中起着重要作用，干扰核苷酸信号通路为控制生物膜形成和提高生物膜对抗生素治疗的敏感性提供了一种可能的方法。本研究合成了 4-芳基偶氮-3,5-二氨基-1H-吡唑（命名为 SP02 和 SP03）的小分子衍生物，并发现这些分子抑制表皮葡萄球菌生物膜形成并诱导生物膜分散。细菌核苷酸信号分子分析表明，SP02 和 SP03 在低至 25μM 的剂量下即可显著降低表皮葡萄球菌中二环腺苷酸（c-di-AMP）的水平，而在高剂量（100μM 或更高）下对多种核苷酸信号（包括环二鸟苷酸（c-di-GMP）、c-di-AMP 和环腺苷酸（cAMP））也有显著影响。然后，我们将这些小分子键合到聚氨酯（PU）生物材料表面，并研究了改性表面上的生物膜形成。结果表明，改性表面在 24 小时和 7 天孵育期间显著抑制生物膜形成。然后用抗生素环丙沙星处理这些生物膜，发现抗生素（2μg/mL）的疗效从未改性 PU 表面的 94.8%提高到 SP02 和 SP03 改性表面的 >99.9%（>3 个对数单位）。结果表明，将干扰核苷酸信号的小分子键合到聚合生物材料表面上，并以中断生物膜形成和提高表皮葡萄球菌感染抗生素疗效的方式是可行的。
