Chang Yoonjee, Yoon Hyunjin, Kang Dong-Hyun, Chang Pahn-Shick, Ryu Sangryeol
Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea.
Department of Molecular Science and Technology, Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon 16499, Republic of Korea.
Int J Food Microbiol. 2017 Mar 6;244:19-26. doi: 10.1016/j.ijfoodmicro.2016.12.007. Epub 2016 Dec 27.
LysSA97 is an endolysin encoded by the bacteriophage SA97, the genome sequence of which has been recently revealed. LysSA97 has lytic activity against a variety of Staphylococcus strains that cause foodborne illness. In order to improve its potential as a biocontrol agent against Staphylococcus, various types of essential oil-derived active compounds were tested in combination with LysSA97; carvacrol exhibited significant synergistic effects when combined with LysSA97. The synergistic antimicrobial activity between endolysin and carvacrol in food products, including milk and beef, were investigated. While LysSA97 (376nM) and carvacrol (3.33mM) showed 0.8±0.2 and 1.0±0.0logCFU/mL reduction in Staphylococcus aureus cells, respectively; when applied alone in bacterial culture, the cocktail containing both at the same concentrations exhibited a bacterial decrease of 4.5±0.2logCFU/mL. The synergistic activity of carvacrol was also reproduced in combination with other endolysins, and their cooperative bactericidal effects were validated in ten additional S. aureus strains, including two methicillin-resistant S. aureus (MRSA), suggesting the wide application of carvacrol as a bactericidal agent coupled with endolysin. When LysSA97 and carvacrol were used in combination in foods, the synergistic activity appeared to be influenced by the total lipid content of foods, and bacteria in skim milk were more drastically inactivated than those in whole milk. Therefore, this is the first report demonstrating that endolysin and carvacrol act synergistically to inactivate S. aureus in food products.
LysSA97是一种由噬菌体SA97编码的内溶素，其基因组序列最近已被揭示。LysSA97对多种导致食源性疾病的葡萄球菌菌株具有裂解活性。为了提高其作为抗葡萄球菌生物防治剂的潜力，将各种类型的精油衍生活性化合物与LysSA97联合进行了测试；香芹酚与LysSA97联合使用时表现出显著的协同效应。研究了内溶素和香芹酚在包括牛奶和牛肉在内的食品中的协同抗菌活性。虽然LysSA97（376 nM）和香芹酚（3.33 mM）分别使金黄色葡萄球菌细胞减少0.8±0.2和1.0±0.0 logCFU/mL；当单独应用于细菌培养时，含有相同浓度两者的混合物使细菌减少了4.5±0.2 logCFU/mL。香芹酚与其他内溶素联合使用时也重现了协同活性，并且它们的协同杀菌作用在另外十种金黄色葡萄球菌菌株中得到了验证，包括两种耐甲氧西林金黄色葡萄球菌（MRSA），这表明香芹酚作为与内溶素联合使用的杀菌剂具有广泛的应用前景。当LysSA97和香芹酚在食品中联合使用时，协同活性似乎受食品总脂质含量的影响，脱脂牛奶中的细菌比全脂牛奶中的细菌更易被灭活。因此，这是第一份证明内溶素和香芹酚协同作用使食品中的金黄色葡萄球菌失活的报告。
