摘要
为制备一种对耐甲氧西林金黄色葡萄球菌(MRSA)具有较好抑菌活性的后生元,研究其抑菌作用及抑菌机制,通过乳酸乳球菌乳亚种Postbio-F3、副干酪乳酪杆菌Postbio-P6、发酵粘液乳杆菌Postbio-Q7复合发酵,制备对MRSA具有较好抑菌活性的后生元(命名YDFF),通过抑菌圈法和生长曲线评估YDFF对MRSA的抑菌活性,并对抑菌活性成分进行初步鉴定;通过测定YDFF对MRSA生物膜的影响、菌体超微结构变化、DNA泄漏以及ROS产生初步探究YDFF对MRSA的抑菌作用机制;采用棋盘法,研究YDFF对MRSA耐药性的影响。结果表明:后生元YDFF对MRSA具有较好抑菌活性,对MRSA的抑菌圈直径为19.1±1.5 mm,且该活性具有较好的pH耐受范围(pH3.0~9.0);YDFF中的胞外多糖无抑菌活性,蛋白酶K可以使YDFF抑菌活性完全失活,说明YDFF中的抑菌活性物质主要为蛋白类成分;YDFF可以显著抑制生物膜的形成,破坏菌体完整性导致DNA泄漏,并可引起细菌胞内ROS浓度升高;YDFF与甲氧西林联合使用时对MRSA的分级抑菌浓度指数(FICI)降低至0.38,表明YDFF可以降低MRSA对甲氧西林的耐药性。后生元YDFF通过抑制生物膜形成、破坏细胞膜结构、提高胞内ROS发挥对MRSA的抑菌作用,且可以显著降低MRSA对抗生素的耐药性,为后生元在食品、医疗中使用提供理论依据。
To prepare a postbiotic with good antibacterial activity against methicillin-resistant Staphylococcus aureus(MRSA),and to study its antibacterial effect and action mode,a postbiotic named YDFF was prepared by co-fermenting Lactococcus lactis subsp Postbio-F3,Lactobacillus paracasei Postbio-P6 and Lactobacillus fermentans Postbio-Q7,its antibacterial activity against MRSA was determined by both inhibition zone and growth curve,and the active ingredients exerting antibacterial activity were preliminarily identified.The antibacterial mechanism of YDFF on MRSA was inves-tigated by detecting the effects of YDFF on MRSA biofilm formation,ultrastructural changes,DNA leakage,and ROS generation.Furthermore,the effect of YDFF on the antibiotic resistance of MRSA to methicillin was explored by ches-sboard method.The results showed that the postbiotic YDFF had good antibacterial activity against MRSA(The diameter of inhibition zone was 19.1±1.5 mm)with wide pH tolerance range(pH3.0~9.0).The extracellular polysaccharides extracted from YDFF had no antibacterial activity,but protease K could completely inactivate its antibacterial activity,indicating that the main antibacterial active substance in YDFF was protein.It was demonstrated that YDFF exhibited antibacterial activity by several ways including inhibiting the formation of biofilms,destroying the cell membrane integrity which resulted in the leakage of DNA,and increasing the concentration of intracellular ROS.Additionally,when YDFF was used combined with methicillin,the fractional inhibitory concentration index(FICI)was significantly decreased to 0.38,indicating YDFF could reduce the antibiotic resistance of MRSA to methicillin.Taken together,YDFF exhibited good antibacterial activity on MRSA by inhibiting the biofilm formation,destroying membrane structure and increasing the intracellular ROS,and reduced the antibiotic resistance to methicillin,which would provide a theoretical basis for the use of postbiotics in food and medicine.
作者
兰冬雪
瞿茜楠
于浩东
黄天
彭传涛
姚国强
赵金山
李兆杰
LAN Dongxue;QU Xinan;YU Haodong;HUANG Tian;PENG Chuantao;YAO Guoqiang;ZHAO Jinshan;LI Zhaojie(College of Food Science and Engineering,Qingdao Agricultural University,Qingdao 266109,China;Qingdao Special Food Research Institute,Qingdao 266109,China;Key Laboratory of Dairy Biotechnology and Engineering,Ministry of Education,Inner Mongolia Agricultural University,Hohhot 010018,China)
出处
《食品工业科技》
CAS
北大核心
2023年第21期154-161,共8页
Science and Technology of Food Industry
基金
山东省自然科学基金面上项目(ZR2020MC217)
国家自然科学基金项目(32101917)。
关键词
后生元
耐甲氧西林金黄色葡萄球菌
抑菌
抑菌机制
生物膜
耐药性
postbiotics
methicillin-resistant Staphylococcus aureus
antibacterial
antibacterial mechanism
biofilm
antibiotic resistance
