N-linked oligosaccharides (N-glycans) derived from milk were recently found to be antipathogenic. This study compares the antimicrobial activity of N-linked glycans and free oligosaccharides from human, bovine, and goat milk against Staphylococcus aureus. Milk N-glycans showed a bactericidal/bacteriostatic effect on the pathogen when compared to free milk oligosaccharides, evidenced by the clear zone from the halo assay, with the order of human milk >goat milk >bovine milk. None of the free milk oligosaccharide samples were bactericidal/bacteriostatic, despite its positive results in growth curve and minimum inhibitory concentration (MIC) assays which are believed to be related to hyperosmosis. Both N-glycans and free milk oligosaccharides can reduce the adhesion of Staphylococcus aureus to Caco-2 cells, however, N-glycans worked significantly more effective than free milk oligosaccharides. Structural analysis of all free oligosaccharide and N-glycan samples showed the obvious interspecies differences, and the structure/function relationship of the respected N-glycans is of interest for future study. The significant bactericidal/bacteriostatic activity possessed by human, bovine, and goat milk N-linked glycans holds great potential as a novel substitute for antibiotics.

中文翻译：

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人乳、牛乳和山羊乳来源的 N-连接寡糖和游离寡糖对金黄色葡萄球菌的抗病原作用比较

最近发现从牛奶中提取的 N-连接寡糖 (N-聚糖) 具有抗病原体作用。本研究比较了人乳、牛乳和山羊乳中的 N-连接聚糖和游离寡糖对金黄色葡萄球菌的抗菌活性。与游离的牛奶寡糖相比，牛奶 N-聚糖对病原体显示出杀菌/抑菌作用，这一点由晕环测定的透明区域证明，其顺序为人乳 > 山羊乳 > 牛乳。尽管在生长曲线和最低抑菌浓度 (MIC) 测定中得到了阳性结果，但这些游离的牛奶寡糖样品都没有杀菌/抑菌作用，这被认为与高渗有关。N-聚糖和游离的牛奶寡糖都可以减少金黄色葡萄球菌对 Caco-2 细胞的粘附，然而，N-聚糖比游离的牛奶寡糖更有效。所有游离寡糖和 N-聚糖样品的结构分析显示出明显的种间差异，受关注的 N-聚糖的结构/功能关系是未来研究的重点。人乳、牛乳和山羊乳 N 连接聚糖具有显着的杀菌/抑菌活性，具有作为抗生素的新型替代品的巨大潜力。