Pourkhosravani Elahe, Dehghan Nayeri Fatemeh, Mohammadi Bazargani Mitra
Agricultural Biotechnology Department, Faculty of Agriculture and Natural Sciences, Imam Khomeini International University (IKIU), Qazvin, Iran.
Medicinal Plant Department, Agriculture Institute (ARI), Iranian Research Organization for Science and Technology (IROST), Tehran, Iran.
AMB Express. 2021 Oct 26;11(1):143. doi: 10.1186/s13568-021-01305-6.
This study sets out to compare the antibacterial and antibiofilm profiles of Ci/Ca EOs alone and in combination together against infectious bacterial strains. MIC assay was carried out to survey the effectiveness of prepared EOs by two-fold serial dilution method and MTT evaluation. Synergic antibacterial properties of EOs against target strains were studied by using checkerboard titration method. Biofilm growth and development were evaluated using CV and XTT reduction assays. Antibacterial activity was observed for EOs against both bacterial strains with stronger activity for CiEO against both bacteria. The synergistic antibacterial effect was observed only against B. subtilis. Based on the FIC index, combinations could not inhibit the growth of E. coli. The pure EOs and their combination inhibited cell attachment for both studied bacteria with stronger effect on E. coli. CV and XTT reduction assays results showed that Ci EO and its combination with CaEO had the highest antibiofilm activity at lowest MIC value 0.08% and 0.04/0.02% against biofilm formed by E. coli and B. subtilis respectively, indicating a high antibiofilm potential. Computational docking analyses also postulated that the active constituents of evaluated EOs have the potential to interact with different bacterial targets, suggested binding mode of action of EOs metabolites. By and large, synergistic anti-biofilm properties of EOs may provide further options for developing novel formula to inhibit a variety of infectious clinical and industrial strains without (or less) toxicity effects on human body.
本研究旨在比较肉桂/小豆蔻挥发油单独及联合使用时对感染性细菌菌株的抗菌和抗生物膜特性。采用微量肉汤稀释法和MTT法进行MIC测定，以检测所制备挥发油的有效性。采用棋盘滴定法研究挥发油对目标菌株的协同抗菌特性。使用结晶紫（CV）和XTT还原试验评估生物膜的生长和发育情况。观察到挥发油对两种细菌菌株均有抗菌活性，其中肉桂挥发油对两种细菌的活性更强。仅观察到对枯草芽孢杆菌有协同抗菌作用。根据FIC指数，联合用药不能抑制大肠杆菌的生长。纯挥发油及其组合对两种受试细菌均有抑制细胞黏附的作用，对大肠杆菌的作用更强。CV和XTT还原试验结果表明，肉桂挥发油及其与小豆蔻挥发油的组合在最低MIC值分别为0.08%和0.04/0.02%时，对大肠杆菌和枯草芽孢杆菌形成的生物膜具有最高的抗生物膜活性，表明其具有很高的抗生物膜潜力。计算对接分析还推测，所评估挥发油的活性成分有可能与不同的细菌靶点相互作用，提示了挥发油代谢产物的结合作用模式。总体而言，挥发油的协同抗生物膜特性可能为开发新型配方提供更多选择，以抑制各种感染性临床和工业菌株，且对人体无（或较小）毒性作用。
