Natural Product Research Center, Korea Institute of Science and Technology, Gangneung, South Korea.
Natural Product Informatics Research Center, Korea Institute of Science and Technology, Gangneung, South Korea.
J Appl Microbiol. 2021 Jul;131(1):93-104. doi: 10.1111/jam.14936. Epub 2020 Dec 5.
The aim of this study was to assess antibacterial activity of a novel Bacillus velezensis strain NST6, and further identify its active compound against pathogenic Staphylococcus strains for clinical therapeutic applications.
In this study, a novel B. velezensis strain NST6 harbouring strong antimicrobial activity against human pathogenic bacteria was isolated from a soil sample. The solvent extract of the strain exhibited strong antibacterial activity against Gram-positive and Gram-negative bacteria in disc diffusion assay and measurement of minimal inhibitory concentration and bactericidal concentration, of which it showed notable efficacy to Staphylococcus species including Staphylococcus epidermidis, Staphylococcus aureus and methicillin-resistant S. aureus. Strong antibacterial effect against pathogenic S. aureus and low toxicity of the bacterial extract were further validated in Caenorhabditis elegans model. Moreover, by antibacterial activity-guided fractionation using RP-HPLC and LC-MS, we defined C -bacillomycin D as the anti-staphylococcal compound produced by the strain.
The primary anti-staphylococcal compound from B. velezensis NST6 was identified as a cyclic lipopeptide, C -bacillomycin D, which proved its potential to treat Staphylococcus strains in vitro and in vivo experiments with insignificant level of toxicity.
We provide an alternative treatment option to Staphylococcus infections by investigating the specific anti-staphylococcal activity of C -bacillomycin D produced by a B. velezensis strain.
本研究旨在评估新型芽孢杆菌 NST6 的抗菌活性，并进一步鉴定其针对致病性葡萄球菌菌株的活性化合物，以用于临床治疗应用。
本研究从土壤样本中分离出一株具有强抗人病原菌活性的新型芽孢杆菌 NST6。该菌株的溶剂提取物在圆盘扩散试验和最小抑菌浓度及杀菌浓度测定中对革兰氏阳性和革兰氏阴性细菌均表现出较强的抗菌活性，其中对表皮葡萄球菌、金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌等葡萄球菌属表现出显著的疗效。该细菌提取物对致病性金黄色葡萄球菌具有较强的抗菌作用且毒性低，在秀丽隐杆线虫模型中得到了进一步验证。此外，通过采用反相高效液相色谱法和 LC-MS 进行抗菌活性导向分离，我们将 C -杆菌霉素 D 定义为该菌株产生的抗葡萄球菌化合物。
从芽孢杆菌 NST6 中鉴定出的主要抗葡萄球菌化合物为环状脂肽 C -杆菌霉素 D，该化合物在体外和体内实验中对金黄色葡萄球菌具有潜在的治疗作用，且毒性水平较低。
通过研究由芽孢杆菌产生的 C -杆菌霉素 D 的特定抗葡萄球菌活性，为金黄色葡萄球菌感染提供了一种替代治疗选择。
