Plant Compounds Enhance the Assay Sensitivity for Detection of Active Bacillus cereus Toxin
Abstract
:1. Introduction
2. Results and Discussion
2.1. Plant Compounds Reduce the Viable Count of B. cereus in Food
Treatment | % CFU reduction | ||
---|---|---|---|
LB | Similac | Soy milk | |
green tea extract | 89 | 97 | 77 |
green tea extract + carvacrol | 100 | 100 | 100 |
green tea extract + bitter almond essential oil | 65 | 77 | 88 |
carvacrol | 99 | 99 | 100 |
bitter almond essential oil | 67 | 87 | 93 |
epicatechin | 2 | 53 | 45 |
epigallocatechin gallate | 99 | 84 | 90 |
PBS | 0 | 0 | 0 |
tetracycline | 100 | 100 | 100 |
2.2. Detection of B. cereus Toxins
2.2.1. Dose-Dependent Inhibition of GFP Protein Synthesis in Transduced Vero Cells by Bacillus cereus Toxins
2.2.2. Detection of Active B. Cereus Toxins in Different Food Items
2.2.3. Enhancement of B. cereus Toxins Detection Using Natural Tea Compounds
2.3. Discussion
3. Experimental Section
3.1. Materials
3.2. Test Substances
- Green tea extract (0.02%)—2 mg + 100 μL EtOH; add 3.9 mL PBS pH 7.0; vortex 1 min; add 6 mL PBS pH 7.0; clear, very slight greenish tinge.
- GTE (0.02%) + carvacrol (Sigma, St. Louis, MO, USA) (0.1%)—3 μL carvacrol + 30 μL EtOH; add 2.967 mL GTE (0.02%) pH 7.0; vortex 1 min; clear, very slight greenish tinge.
- GTE (0.02%) + bitter almond essential oil (0.1%) (Lhasa Karnak)—3 μL bitter almond EO + 30 μL EtOH; add 2.967 mL GTE (0.02%) pH 7.0; vortex 1 min; clear, very slight greenish tinge.
- Carvacrol (0.1%)—3 μL carvacrol + 30 μL EtOH; add 2.967 mL PBS pH 7.0; vortex 1 min; very slightly yellow.
- Bitter almond essential oil (0.1%)—3 μL bitter almond EO + 30 μL EtOH; add 2.967 mL PBS pH 7.0; vortex 1 min; clear.
- Epicatechin (Sigma) (0.02%)—2 mgs in 100 μL EtOH; add 3.9 mL PBS pH 7.0; vortex 1 min; add 6 mL PBS pH 7.0; clear solution.
- Epigallocatechin gallate (Chromadex, Irvine, CA, USA) (0.02%)—2 mgs in 100 μL EtOH; add 3.9 mL PBS pH 7.0; vortex 1 min; add 6 mL PBS pH 7.0, clear.
3.3. Determination of Bactericidal Effect of Plant Compound by Viable Bacteria Cell Counts
3.4. Determination of Toxin Activity
3.4.1. Cell Culture
3.4.3. Plaque Assays for Purification and Titration of the Adenovirus
3.4.4. Quantifying B. cereus Toxin Activity
3.5. Statistical Analysis
4. Conclusions
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Rasooly, R.; Hernlem, B.; He, X.; Friedman, M. Plant Compounds Enhance the Assay Sensitivity for Detection of Active Bacillus cereus Toxin. Toxins 2015, 7, 835-845. https://doi.org/10.3390/toxins7030835
Rasooly R, Hernlem B, He X, Friedman M. Plant Compounds Enhance the Assay Sensitivity for Detection of Active Bacillus cereus Toxin. Toxins. 2015; 7(3):835-845. https://doi.org/10.3390/toxins7030835
Chicago/Turabian StyleRasooly, Reuven, Bradley Hernlem, Xiaohua He, and Mendel Friedman. 2015. "Plant Compounds Enhance the Assay Sensitivity for Detection of Active Bacillus cereus Toxin" Toxins 7, no. 3: 835-845. https://doi.org/10.3390/toxins7030835