Katsipis Georgios, Aivaliotis Michalis, Pantazaki Anastasia A
Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Laboratory of Neurodegenerative Diseases (LND), Center for Interdisciplinary Research and Innovation (CIRI), Aristotle University of Thessaloniki, 57001 Thessaloniki, Greece.
Microorganisms. 2025 Aug 11;13(8):1875. doi: 10.3390/microorganisms13081875.
biofilms are implicated in the development of persistent infections and increased antibiotic resistance, posing a significant challenge in clinical settings. These biofilms enhance bacterial survival by forming protective extracellular matrices, rendering conventional treatments less effective. Serrapeptase (SPT), a proteolytic enzyme, has emerged as a potential anti-biofilm agent due to its ability to degrade biofilm components and disrupt bacterial adhesion. In this study, we report the inhibitory effect of SPT against biofilm and its effect on key virulence factors. In vitro assays, including crystal violet staining, optical and fluorescence microscopy, and viability measurements, revealed the dose-dependent inhibition of biofilm formation (IC = 14.2 ng/mL), reduced biofilm (-92%, 500 ng/mL) and planktonic viability (-45%, 500 ng/mL), and a marked loss of amyloid curli fibers. SPT treatment also lowered the levels of key virulence factors: cellular and secreted lipopolysaccharides (-76%, 8 ng/mL; -94%, 32 ng/mL), flagellin (-63%, 8 ng/mL), and peptidoglycan (-29%, 125 ng/mL). Mechanistically, SPT induced a phosphate-dysregulating response: secreted alkaline phosphatase activity rose (+70%, 125 ng/mL) while cellular DING/PstS proteins declined (-84%, 64 ng/mL), correlating strongly with biofilm inhibition. In silico docking further suggests direct interactions between SPT and the curli subunits CsgA and CsgB, potentially blocking fiber polymerization. Together, these findings position SPT as a powerful non-antibiotic biofilm disruptor against , offering a promising strategy to undermine bacterial persistence and resistance by targeting both structural matrix components and metabolic regulatory pathways.
生物膜与持续性感染的发展以及抗生素耐药性增加有关，在临床环境中构成了重大挑战。这些生物膜通过形成保护性细胞外基质来提高细菌的存活率，使传统治疗效果降低。舍雷肽酶（SPT）是一种蛋白水解酶，由于其能够降解生物膜成分并破坏细菌粘附，已成为一种潜在的抗生物膜剂。在本研究中，我们报告了SPT对生物膜的抑制作用及其对关键毒力因子的影响。包括结晶紫染色、光学和荧光显微镜以及活力测量在内的体外试验表明，生物膜形成受到剂量依赖性抑制（IC = 14.2 ng/mL），生物膜减少（-92%，500 ng/mL）和浮游菌活力降低（-45%，500 ng/mL），并且淀粉样卷曲纤维明显减少。SPT处理还降低了关键毒力因子的水平：细胞内和分泌的脂多糖（-76%，8 ng/mL；-94%，32 ng/mL）、鞭毛蛋白（-63%，8 ng/mL）和肽聚糖（-29%，125 ng/mL）。从机制上讲，SPT诱导了磷酸盐调节异常反应：分泌的碱性磷酸酶活性升高（+70%，125 ng/mL），而细胞内DING/PstS蛋白下降（-84%，64 ng/mL），这与生物膜抑制密切相关。计算机对接进一步表明SPT与卷曲蛋白亚基CsgA和CsgB之间存在直接相互作用，可能会阻止纤维聚合。总之，这些发现表明SPT是一种强大的抗生物膜非抗生素，通过靶向结构基质成分和代谢调节途径，为破坏细菌的持续性和耐药性提供了一种有前景 的策略。
