The inhibitory and bactericidal activities of thyme oil against the foodborne multiple antibiotics-resistant Enterococcus faecalis biofilm were evaluated in this study. Gas chromatography-mass spectrometry revealed that more than 70% of the composition of thyme oil is thymol. Crystal violet staining assay showed that 128 and 256 μg/mL thyme oil significantly inhibited the biofilm formation of E. faecalis . The cell adherence of E. faecalis , as shown by its swimming and swarming motilities, was reduced by thyme oil. The exopolysaccharide ( EPS ) quantification assay showed that thyme oil inhibited the EPS synthesis in E. faecalis biofilms. The 3D-view observations through confocal laser scanning and scanning electron microscopy suggested that cell adherence and biofilm thickness were decreased in thyme oil–treated biofilms. Quantitative real-time analyses showed that the transcription of ebp and epa gene clusters, which were related to cell mobility and EPS production, was inhibited by thyme oil. Thus, thyme oil effectively inhibited the biofilm formation of E. faecalis by affecting cell adherence and EPS synthesis. Furthermore, 2,048 and 4,096 μg/mL thyme oil can effectively inactivate E. faecalis population in the mature E. faecalis biofilms by 5.75 and 7.20 log CFU/mL, respectively, after 30 min of treatment. Thus, thyme oil at different concentrations can be used as an effective antibiofilm or germicidal agent to control E. faecalis biofilms.

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3-Phenyllactic acid (PLA) was reported to have an effective antimicrobial activity. This study evaluated the antimicrobial activity of PLA against foodborne Enterococcus faecalis and its effect on cell membrane. The minimum concentration of PLA to inactivate E. faecalis in brain heart infusion broth was 5 mg/mL. PLA solutions of 5 and 10 mg/mL can inactivate E. faecalis population ≥6 log CFU/mL within 60 and 30 min, respectively. The cell membranes of most E. faecalis cells were damaged after PLA treatment according to the images of scanning electron microscopy and transmission electron microscopy. The differences in the regions of cell membrane protein, fatty acid, and polysaccharide were revealed by Fourier transform infrared spectroscopy, which further indicated cell membrane damages. The cell membrane permeability was increased when the concentration of PLA treatment was increased in the membrane permeability assays. Finally, almost all bacterial cells were damaged after treatment with 10 mg/mL PLA for 30 min, further confirmed by flow cytometry analysis. This study concluded that PLA is effective in inactivating E. faecalis cells through the leakage of intracellular components caused by cell membrane damage.

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A first-order semilinear fuzzy differential inclusion with fuzzy impulse characteristics and linear boundary conditions is considered in separable Banach spaces. By means of semigroup properties, stacking approach and the fixed point theorem for multivalued map due to Dhage, the existence results for fuzzy solution are established. Some general criteria are presented for a class of semilinear fuzzy differential inclusions including higher dimensional and infinite dimensional uncertain systems, and the conditions for existence of solutions in the results are concise and mild. Also, several examples are given to illustrate the utility and applicability.