Abstract

Enteropathogenic Escherichia coli E2346/69 (EPEC) has caused foodborne outbreaks worldwide and the bacterium forms antimicrobial-tolerant biofilms. The anti-biofilm formation of various components of essential oils extracted from selected medicinal plants were investigated and tested on EPEC and wild strains of E. coli. Oils extracted from the family Asteraceae and their major common constituents at 0.031 and 0.062% (V/v) were found to significantly inhibit biofilm formation without affecting the growth of planktonic cells. In addition, three plants belonging to this family (Artemisia herba alba, Artemisia campestris and Artemisia absinthium) played important roles in the antimicrobial activity. Interestingly, their essential oils reduced the ability of E. coli (the EPEC and K12 strains) to form a biofilm. The crystal violet reduction assay showed that the plant extracts tested reduced biofilm formation with the inhibition of bacterial attachment up to 45% for EPEC and 70% for E. coli K-12 after 24 h treatment at 0.62 mg ml⁻¹, demonstrating that Artemisia oils had a high anti-biofilm activity on the bacteria tested. The results indicate that the locus of enterocyte effacement (LEE) acquired by horizontal transfer promotes the formation of the attaching and effacing (A/E) lesion and increases the capacity of the photogen strain (EPEC) to form a biofilm. The chemical composition of the volatile compounds was obtained by gas chromatography-mass spectrometry analysis, which showed that the essential oils consisted of thirty-four compounds. Chamazulene (39.21%), β-pinene (32.07%), and α-thujone (29.39%) were the main constituents of the essential oils of A. herba alba, A. absinthium and A. campestris, respectively.

摘要

肠致病性大肠杆菌中的全球E2346 / 69（EPEC）已经引起食源性疾病暴发和细菌形式抗菌的容错生物膜。从EPEC和大肠杆菌的野生菌株中研究和测试了从精选药用植物中提取的香精油各种成分的抗生物膜形成。发现从菊科（Asteraceae）及其主要共同成分中提取的油的含量分别为0.031和0.062％（V / v），可显着抑制生物膜的形成，而不会影响浮游细胞的生长。此外，属于该科的三种植物（青蒿，青蒿和苦艾））在抗菌活性中起着重要作用。有趣的是，它们的精油降低了E的能力。大肠杆菌（EPEC和K12菌株）形成生物膜。结晶紫减少测定表明，该植物提取物测试的减少生物膜形成与细菌附着起来的抑制至45％为EPEC和70％为大肠杆菌0.62毫克毫升K-12 24小时后治疗^-1，这表明蒿油对测试的细菌具有很高的抗生物膜活性。结果表明，通过水平转移获得的肠上皮细胞抹除（LEE）的基因座促进了附着和抹除（A / E）病变的形成，并增加了光原菌株（EPEC）形成生物膜的能力。通过气相色谱-质谱分析获得挥发性化合物的化学组成，表明精油由三十四种化合物组成。母菊薁（39.21％），β蒎烯（32.07％），和α-侧柏酮（29.39％）为的精油的主要成分A.草粉，A.苦艾和A.油菜，分别。