Department of Food Science and Technology, Shanghai Jiao Tong University, Shanghai 200240, China.
Department of Food Science and Technology, Shanghai Jiao Tong University, Shanghai 200240, China.
J Dairy Sci. 2022 Mar;105(3):2011-2024. doi: 10.3168/jds.2021-21221. Epub 2021 Dec 23.
Multidrug-resistant (MDR) Staphylococcus aureus and its biofilm formation have been challenging to control in milk and dairy industries. Biofilms formed by Staph. aureus may result in the failure of antibacterial agents and disinfectants to penetrate the biofilm in an attempt to control contamination. Novel natural antibacterial agents are required to combat MDR bacteria and biofilms. In this study, we evaluated the bactericidal, antibiofilm, and antimotility effects of Rumex japonicus Houtt. (RJH) extract on MDR Staph. aureus isolated from milk. The RJH extract exhibited good antibacterial activity against MDR strains with minimum inhibitory concentrations (MIC) ranging from 0.78 to 6.25 mg/mL and minimum bactericidal concentrations ranging from 3.125 to 12.5 mg/mL. The extract showed strong inhibition of biofilm formation (81.9%) at sub-MIC value and eradication of biofilm at higher concentrations. The motility of Staph. aureus was effectively blocked by the extract. Major compounds emodin, chrysophanol, and physcion were identified in RJH extract using HPLC-linear trap quadrupole (LTQ)/Orbitrap-mass spectrometry. The extract was nontoxic to human epithelial cell lines such as Caco-2 and HT-29 cell lines at concentrations ranging from 0.1 to 0.5 mg/mL, and from 0.1 to 0.75 mg/mL, respectively. These findings suggest that RJH extract could be an alternative to synthetic preservatives in milk and dairy products.
耐多药（MDR）金黄色葡萄球菌及其生物膜的形成一直是奶及奶制品行业难以控制的问题。金黄色葡萄球菌形成的生物膜可能导致抗菌剂和消毒剂无法穿透生物膜，从而无法控制污染。需要新型天然抗菌剂来对抗 MDR 细菌和生物膜。在这项研究中，我们评估了酸模（Rumex japonicus Houtt.）提取物对牛奶中分离出的耐多药金黄色葡萄球菌的杀菌、抗生物膜和抗运动性作用。RJH 提取物对 MDR 菌株表现出良好的抗菌活性，最小抑菌浓度（MIC）范围为 0.78 至 6.25mg/mL，最小杀菌浓度范围为 3.125 至 12.5mg/mL。该提取物在亚 MIC 值下表现出强烈的抑制生物膜形成作用（81.9%），并在较高浓度下可消除生物膜。提取物能有效抑制金黄色葡萄球菌的运动性。使用高效液相色谱-线性阱四极杆（LTQ）/轨道阱质谱法在 RJH 提取物中鉴定出大黄素、大黄酚和大黄素甲醚等主要化合物。该提取物在 0.1 至 0.5mg/mL 浓度范围内对人上皮细胞系如 Caco-2 和 HT-29 细胞系无毒性，在 0.1 至 0.75mg/mL 浓度范围内对人上皮细胞系无毒性。这些发现表明，RJH 提取物可作为牛奶和奶制品中合成防腐剂的替代品。
