Paul Payel, Roy Ritwik, Das Sharmistha, Sarkar Sarita, Chatterjee Sudipta, Mallik Moumita, Shukla Aditya, Chakraborty Poulomi, Tribedi Prosun
Microbial Ecology Research Laboratory, Department of Biotechnology, The Neotia University, Sarisha, West Bengal, 743368, India.
Department of Microbiology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, 700019, India.
Folia Microbiol (Praha). 2023 Oct;68(5):801-811. doi: 10.1007/s12223-023-01054-y. Epub 2023 Apr 25.
Microorganisms embedded within an extracellular polymeric matrix are known as biofilm. The extensive use of antibiotics to overcome the biofilm-linked challenges has led to the emergence of multidrug-resistant strains. Staphylococcus aureus is one such nosocomial pathogen that is known to cause biofilm-linked infections. Thus, novel strategies have been adopted in this study to inhibit the biofilm formation of S. aureus. Two natural compounds, namely, 1,4-naphthoquinone (a quinone derivative) and tryptophan (aromatic amino acid), have been chosen as they could independently show efficient antibiofilm activity. To enhance the antibiofilm potential, the two compounds were combined and tested against the same organism. Several experiments like crystal violet (CV) assay, protein estimation, extracellular polymeric substance (EPS) extraction, and estimation of metabolic activity confirmed that the combination of the two compounds could significantly inhibit the biofilm formation of S. aureus. To comprehend the underlying mechanism, efforts were further directed to understand whether the two compounds could inhibit biofilm formation by compromising the cell surface hydrophobicity of the bacteria. The results revealed that the cell surface hydrophobicity got reduced by ~ 49% when the compounds were applied together. Thus, the combinations could show enhanced antibiofilm activity by attenuating cell surface hydrophobicity. Further studies revealed that the selected concentrations of the compounds could disintegrate (~ 70%) the pre-existing biofilm of the test bacteria without showing any antimicrobial activity. Hence, the combined application of tryptophan and 1,4-naphthoquinone could be used to inhibit the biofilm threats of S. aureus.
嵌入细胞外聚合物基质中的微生物被称为生物膜。为克服与生物膜相关的挑战而广泛使用抗生素已导致多重耐药菌株的出现。金黄色葡萄球菌就是这样一种已知会引起与生物膜相关感染的医院病原体。因此，本研究采用了新策略来抑制金黄色葡萄球菌的生物膜形成。选择了两种天然化合物，即1,4 - 萘醌（一种醌衍生物）和色氨酸（芳香族氨基酸），因为它们各自能显示出有效的抗生物膜活性。为增强抗生物膜潜力，将这两种化合物组合并针对同一生物体进行测试。诸如结晶紫（CV）测定、蛋白质定量、细胞外聚合物物质（EPS）提取以及代谢活性评估等多项实验证实，这两种化合物的组合能显著抑制金黄色葡萄球菌的生物膜形成。为了解潜在机制，进一步努力探究这两种化合物是否通过损害细菌的细胞表面疏水性来抑制生物膜形成。结果显示，当两种化合物一起应用时，细胞表面疏水性降低了约49%。因此，该组合可通过减弱细胞表面疏水性表现出增强的抗生物膜活性。进一步研究表明，所选浓度的化合物可分解（约70%）受试细菌预先形成的生物膜，且未显示出任何抗菌活性。因此，色氨酸和1,4 - 萘醌的联合应用可用于抑制金黄色葡萄球菌的生物膜威胁。
