Antibacterial activity and mechanism of bifidocin A against Listeria monocytogenes
Antibacterial activity and mechanism of bifidocin A against Listeria monocytogenes
复制标题
双歧杆菌A对单核细胞增生李斯特氏菌的抗菌活性及机制
DOI：
10.1016/j.foodcont.2016.09.036
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发表时间：
2017-03-01
期刊：
影响因子：
6
通讯作者：
Sun, Baoguo
中科院分区：
文献类型：
--
作者：
Liu, Guorong;Ren, Guimei;Sun, Baoguo
双歧杆菌素A是由动物双歧杆菌（Bifidobacterium animalis）BB 04产生的一种新型细菌素，对多种革兰氏阳性和革兰氏阴性食源性细菌具有抗菌活性。本研究的目的是研究双歧杆菌素A对单核细胞增生李斯特菌的抗菌活性和作用机制，李斯特菌是对该细菌素最敏感的细菌之一。双歧杆菌素A对单核细胞增生李斯特菌35152的最低抑菌浓度（MIC）为0.029 mg/mL。时间杀伤试验表明，双歧杆菌素A有效地抑制单核细胞增生李斯特菌的生长，在时间和浓度依赖性的方式。通过分析其在MIC下对单核细胞增生李斯特菌的细胞形态、细胞内组织、膜通透性、膜完整性和膜质子动力（PMF）的影响，研究了双歧杆菌素A的作用机制。扫描和透射电子显微镜分析表明，bifidocin A诱导单核细胞增生性李斯特菌细胞的形态和细胞内组织的改变。共聚焦激光扫描显微镜图像显示，用双歧杆菌素A处理的单核细胞增生李斯特菌细胞摄取碘化丙啶。Bifidocin A处理还引起L.单核细胞增多症细胞这些结果表明，双歧杆菌素A发挥其抗单核细胞增生李斯特菌的作用，通过细胞质膜PMF的消散，增加膜通透性，细胞膜孔的形成，破坏膜的完整性，并最终完全解体的细胞。(C)2016爱思唯尔有限公司版权所有
Bifidocin A, produced by Bifidobacterium animalis BB04, is a novel bacteriocin with antimicrobial activity against a wide range of gram-positive and gram-negative foodborne bacteria. The objective of this study was to investigate the antibacterial activity and mechanism of action of bifidocin A against Listeria monocytogenes, one of the most susceptible bacteria to this bacteriocin. The minimum inhibitory concentration (MIC) of bifidocin A for L monocytogenes 35152 was 0.029 mg/mL. Time-kill assays showed that bifidocin A effectively inhibited the growth of L monocytogenes in a time-and concentration dependent manner. The mechanism of action of bifidocin A was studied by analyzing its effects at a MIC on the cell morphology, intracellular organization, membrane permeability, membrane integrity, and membrane proton motive force (PMF) of L monocytogenes. Scanning and transmission electron microscopy analyses showed that bifidocin A induced alterations in the morphology and intracellular organization of L monocytogenes cells. Confocal laser scanning microscopy images showed that L monocytogenes cells treated with bifidocin A took up propidium iodide. Bifidocin A treatment also induced the leakage of K+ and inorganic phosphate, the hydrolysis and release of ATP, and a collapse of the transmembrane electrical potential and pH gradient in L. monocytogenes cells. These results suggested that bifidocin A exerted its anti-Listeria monocytogenes effect through the dissipation of the cytoplasmic membrane PMF, increased membrane permeability, cell membrane pore formation, destruction of membrane integrity, and ultimately complete disintegration of the cells. (C) 2016 Elsevier Ltd. All rights reserved.