Kraszewska Joanna, Beckett Michael C, James Tharappel C, Bond Ursula
Microbiology Department, Moyne Institute, School of Genetics and Microbiology, Trinity College Dublin, Dublin, Ireland.
Microbiology Department, Moyne Institute, School of Genetics and Microbiology, Trinity College Dublin, Dublin, Ireland
Appl Environ Microbiol. 2016 Jun 30;82(14):4288-4298. doi: 10.1128/AEM.00558-16. Print 2016 Jul 15.
Antimicrobial peptides offer potential as novel therapeutics to combat food spoilage and poisoning caused by pathogenic and nonpathogenic bacteria. Our previous studies identified the peptide human beta-defensin 3 (HBD3) as a potent antimicrobial agent against a wide range of beer-spoiling bacteria. Thus, HBD3 is an excellent candidate for development as an additive to prevent food and beverage spoilage. To expand the repertoire of peptides with antimicrobial activity against bacteria associated with food spoilage and/or food poisoning, we carried out an in silico discovery pipeline to identify peptides with structure and activity similar to those of HBD3, focusing on peptides of plant origin. Using a standardized assay, we compared the antimicrobial activities of nine defensin-like plant peptides to the activity of HBD3. Only two of the peptides, fabatin-2 and Cp-thionin-2, displayed antimicrobial activity; however, the peptides differed from HBD3 in being sensitive to salt and were thermostable. We also compared the activities of several ultrashort peptides to that of HBD3. One of the peptides, the synthetic tetrapeptide O3TR, displayed biphasic antimicrobial activity but had a narrower host range than HBD3. Finally, to determine if the peptides might act in concert to improve antimicrobial activity, we compared the activities of the peptides in pairwise combinations. The plant defensin-like peptides fabatin-2 and Cp-thionin-2 displayed a synergistic effect with HBD3, while O3TR was antagonistic. Thus, some plant defensin-like peptides are effective antimicrobials and may act in concert with HBD3 to control bacteria associated with food spoilage and food poisoning.
Food spoilage and food poisoning caused by bacteria can have major health and economic implications for human society. With the rise in resistance to conventional antibiotics, there is a need to identify new antimicrobials to combat these outbreaks in our food supply. Here we screened plant peptide databases to identify peptides that share structural similarity with the human defensin peptide HBD3, which has known antimicrobial activity against food-spoiling bacteria. We show that two of the plant peptides display antimicrobial activity against bacteria associated with food spoilage. When combined with HBD3, the peptides are highly effective. We also analyzed the activity of an easily made ultrashort synthetic peptide, O3TR. We show that this small peptide also displays antimicrobial activity against food-spoiling bacteria but is not as effective as HBD3 or the plant peptides. The plant peptides identified are good candidates for development as natural additives to prevent food spoilage.
抗菌肽具有作为新型疗法对抗由致病和非致病细菌引起的食品腐败和中毒的潜力。我们之前的研究确定肽人β-防御素3（HBD3）是一种针对多种啤酒腐败细菌的强效抗菌剂。因此，HBD3是作为添加剂用于预防食品和饮料腐败的极佳开发候选物。为了扩大具有抗食品腐败和/或食物中毒相关细菌活性的肽库，我们开展了一项计算机发现流程，以鉴定结构和活性与HBD3相似的肽，重点关注植物来源的肽。使用标准化测定法，我们将9种防御素样植物肽的抗菌活性与HBD3的活性进行了比较。只有两种肽，即fabatin-2和Cp-硫堇蛋白-2，显示出抗菌活性；然而，这些肽与HBD3不同，它们对盐敏感且具有热稳定性。我们还将几种超短肽的活性与HBD3的活性进行了比较。其中一种肽，即合成四肽O3TR，显示出双相抗菌活性，但宿主范围比HBD3窄。最后，为了确定这些肽是否可能协同作用以提高抗菌活性，我们比较了肽两两组合时的活性。植物防御素样肽fabatin-2和Cp-硫堇蛋白-2与HBD3显示出协同效应，而O3TR则具有拮抗作用。因此，一些植物防御素样肽是有效的抗菌剂，可能与HBD3协同作用以控制与食品腐败和食物中毒相关的细菌。
由细菌引起的食品腐败和食物中毒可能对人类社会产生重大的健康和经济影响。随着对传统抗生素耐药性的增加，需要鉴定新的抗菌剂来对抗我们食品供应中的这些疫情爆发。在这里，我们筛选了植物肽数据库，以鉴定与人类防御素肽HBD3结构相似的肽，HBD3对食品腐败细菌具有已知的抗菌活性。我们表明，两种植物肽对与食品腐败相关的细菌显示出抗菌活性。与HBD3联合使用时，这些肽非常有效。我们还分析了一种易于制备的超短合成肽O3TR的活性。我们表明，这种小肽也对食品腐败细菌显示出抗菌活性，但不如HBD3或植物肽有效。所鉴定的植物肽是作为预防食品腐败的天然添加剂进行开发的良好候选物。
