College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad047.
Carbapenemase-producing E. coli is a grave public health concern as the potential emergence of resistant strains and their transmission. Isoorientin belongs to a potential antimicrobial flavonoid compound existing in several plants, while the research on the antimicrobial activity of isoorientin is limited thus far. We evaluated the antimicrobial and antibiofilm effects of isoorientin against biofilm-forming carbapenem non-sensitive Escherichia coli (E. coli) from raw milk of goats, and explored its molecular mechanisms. Isoorientin showed obvious antimicrobial ability with the minimum inhibitory concentration (MIC), and it exhibited synergistic activity with traditional antimicrobials against the carbapenem non-sensitive E. coli. Isoorientin could also significantly inhibit the carbapenem non-sensitive E. coli biofilm formation and destroy the established biofilms, with the percentage of inhibition ranging from 27.8% to 75% at MIC, and the corresponding percentage of eradication ranging from 15.3% to 61.6%, respectively. Confocal laser scanning microscopy (CLSM) observation and scanning electron microscopy (SEM) images indicated that the E. coli biofilm reduced in thickness with increasing concentrations of isoorientin. Dose-dependent decrease in eDNA revealed that isoorientin interacted with the extracellular polymeric substances (EPS) of the biofilm. qRT-PCR assay for the biofilm-forming associated genes further confirmed the above results. Overall, these results concluded that the isoorientin has significant antimicrobial and antibiofilm activity against carbapenem non-sensitive E. coli, and has potential application in prevention of food contamination and spoilage.
产碳青霉烯酶大肠杆菌是一个严重的公共卫生关注点，因为其可能出现耐药菌株并传播。异荭草苷属于一种存在于多种植物中的潜在抗菌类黄酮化合物，而迄今为止，关于异荭草苷的抗菌活性的研究有限。我们评估了异荭草苷对来自山羊生乳的产碳青霉烯非敏感型大肠杆菌（E. coli）的抗菌和抗生物膜作用，并探讨了其分子机制。异荭草苷表现出明显的抗菌能力，其最小抑菌浓度（MIC），并且与传统抗菌药物对产碳青霉烯非敏感型大肠杆菌表现出协同作用。异荭草苷还可以显著抑制产碳青霉烯非敏感型大肠杆菌生物膜的形成并破坏已建立的生物膜，在 MIC 时，抑制率从 27.8%到 75%不等，相应的消除率从 15.3%到 61.6%不等。共聚焦激光扫描显微镜（CLSM）观察和扫描电子显微镜（SEM）图像表明，随着异荭草苷浓度的增加，大肠杆菌生物膜的厚度减少。依赖剂量的 eDNA 减少表明异荭草苷与生物膜的细胞外聚合物质（EPS）相互作用。生物膜形成相关基因的 qRT-PCR 检测进一步证实了上述结果。总的来说，这些结果表明异荭草苷对产碳青霉烯非敏感型大肠杆菌具有显著的抗菌和抗生物膜活性，并且在预防食品污染和变质方面具有潜在的应用价值。
