Hulankova Radka
Department of Animal Origin Food and Gastronomic Sciences, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, 61242 Brno, Czech Republic.
Antibiotics (Basel). 2022 Jan 25;11(2):150. doi: 10.3390/antibiotics11020150.
So far there is no internationally accepted, standardized method for MIC determination of natural substances such as essential oils (EOs). The aim of this study was to elucidate how much the MIC values obtained from various studies using different culture media are comparable. The median MICs for cinnamon essential oil (EO) obtained by broth dilution were 517, 465 and 517 µg/mL for Mueller-Hinton Broth (MHB), Tryptone Soya Broth (TSB) and Brain Heart Infusion (BHI), respectively. The MIC values for oregano EO were significantly ( < 0.001) lower in MHB than in highly nutritious media; the median MICs were 616 µg/mL for MHB and 474 µg/mL for TSB and BHI. This statistically significant difference was noted for all the pathogens studied ( Enteritidis, O157, , ). In the presence of oregano EO lag phase was also much less prolonged in MHB (by 6-17%) than in the other media (by 92-189%). Some components of EOs may bind to starch in MHB; since the phenomenon seems to be selective and EO dependent, the use of MHB for comparison of antimicrobial properties of various EOs thus cannot be recommended.
到目前为止，对于诸如精油（EOs）等天然物质，尚无国际认可的标准化最低抑菌浓度（MIC）测定方法。本研究的目的是阐明使用不同培养基的各种研究所得出的MIC值具有多大的可比性。通过肉汤稀释法测得的肉桂精油（EO）在穆勒 - 欣顿肉汤（MHB）、胰蛋白胨大豆肉汤（TSB）和脑心浸液（BHI）中的MIC中位数分别为517、465和517μg/mL。牛至EO在MHB中的MIC值显著（<0.001）低于在高营养培养基中的值；MHB中的MIC中位数为616μg/mL，TSB和BHI中的为474μg/mL。在所研究的所有病原体（肠炎沙门氏菌、O157等）中均观察到这种统计学上的显著差异。在存在牛至EO的情况下，MHB中的迟缓期延长程度（6 - 17%）也远低于其他培养基（92 - 189%）。EO的某些成分可能会与MHB中的淀粉结合；由于这种现象似乎具有选择性且依赖于EO，因此不建议使用MHB来比较各种EO的抗菌特性。
