Research Institute of Cell Culture, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea.
Department of Life Science, School of Basic Science and Research, Sharda University, Greater Noida, Uttar Pradesh, India.
Appl Biochem Biotechnol. 2023 Sep;195(9):5379-5393. doi: 10.1007/s12010-022-03971-z. Epub 2022 May 20.
Staphylococcus aureus is an important bacterial pathogen responsible for biofilm formation in medical devices. Due to the increasing antibiotic resistance of S. aureus, it is necessary to search for new anti-biofilm agents. In this study, the cell-free supernatant of Bacillus thuringiensis inhibited biofilm formation up to 93% and dispersed biofilms up to 83% without affecting the growth of S. aureus. The ethyl acetate extract of B. thuringiensis cell-free supernatant exhibited a dose-dependent anti-biofilm activity against S. aureus with the biofilm inhibition concentration ranging from 8 to 64 µg/mL. Scanning electron microscopy revealed that the cell-free supernatant extract of B. thuringiensis resulted in a significant reduction in S. aureus biofilms. The ethyl acetate extract of cell-free supernatant of B. thuringiensis was found to contain various compounds with structural similarity to known anti-biofilm compounds. In particular, squalene, cinnamic acid derivatives, and eicosapentaene seem to act synergistically against S. aureus biofilms. Hence, B. thuringiensis cell-free supernatant proved to be effective against S. aureus biofilms. The results clearly show the potential of natural molecules produced by B. thuringiensis as alternative therapies with anti-biofilm activity instead of bactericidal properties.
金黄色葡萄球菌是一种重要的细菌病原体，可导致医疗器械形成生物膜。由于金黄色葡萄球菌的抗生素耐药性不断增加，因此有必要寻找新的抗生物膜剂。在这项研究中，苏云金芽孢杆菌的无细胞上清液可抑制生物膜形成高达 93%，分散生物膜高达 83%，而不影响金黄色葡萄球菌的生长。苏云金芽孢杆菌无细胞上清液的乙酸乙酯提取物对金黄色葡萄球菌表现出剂量依赖性的抗生物膜活性，生物膜抑制浓度范围为 8 至 64μg/mL。扫描电子显微镜显示，苏云金芽孢杆菌的无细胞上清液提取物导致金黄色葡萄球菌生物膜显著减少。苏云金芽孢杆菌无细胞上清液的乙酸乙酯提取物中含有多种与已知抗生物膜化合物结构相似的化合物。特别是，角鲨烯、肉桂酸衍生物和二十碳五烯似乎对金黄色葡萄球菌生物膜具有协同作用。因此，苏云金芽孢杆菌无细胞上清液对金黄色葡萄球菌生物膜有效。结果清楚地表明，苏云金芽孢杆菌产生的天然分子具有作为抗生物膜活性替代疗法的潜力，而不是杀菌特性。
