1. Effect of gamma radiation and oregano essential oil on murein and ATP concentration of Staphylococcus aureus
- Author
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Stéphane Caillet, Laura Ursachi, François Shareck, Monique Lacroix, Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), and This research was supported by the Natural Sciences and Engineering Research Council of Canadian (NSERC)
- Subjects
medicine.disease_cause ,law.invention ,MESH: Dose-Response Relationship, Drug ,MESH: Oils, Volatile ,Foodborne Diseases ,Adenosine Triphosphate ,law ,[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,Cell Wall ,Origanum ,MESH: Adenosine Triphosphate ,MESH: Staphylococcus aureus ,Chromatography, High Pressure Liquid ,MESH: Microbial Viability ,0303 health sciences ,MESH: Microbial Sensitivity Tests ,biology ,MESH: Peptidoglycan ,Staphylococcus aureus ,MESH: Microscopy, Electron, Transmission ,Intracellular ,Microbial Sensitivity Tests ,Peptidoglycan ,Viable but nonculturable ,Microbiology ,03 medical and health sciences ,Minimum inhibitory concentration ,MESH: Cell Wall ,Microscopy, Electron, Transmission ,Food Preservation ,MESH: Dose-Response Relationship, Radiation ,medicine ,Extracellular ,Oils, Volatile ,MESH: Chromatography, High Pressure Liquid ,MESH: Foodborne Diseases ,Cell damage ,Essential oil ,030304 developmental biology ,Microbial Viability ,Dose-Response Relationship, Drug ,030306 microbiology ,Dose-Response Relationship, Radiation ,MESH: Gamma Rays ,medicine.disease ,biology.organism_classification ,Gamma Rays ,MESH: Origanum ,MESH: Food Preservation ,Bacteria ,Food Science - Abstract
International audience; The study was carried out to evaluate the effects of gamma-irradiation alone or in combination with oregano essential oil on murein composition of Staphylococcus aureus and on the intracellular and extracellular concentration of ATP. The bacterial strain was treated with 3 irradiation doses: 1.2 kGy to induce cell damage, 2.9 kGy to obtain a viable but nonculturable state, and 3.5 kGy to cause cell death. Oregano essential oil was used at 0.010% and 0.013% (w/v), which is the minimum inhibitory concentration (MIC). All treatments had a significant effect (P < or = 0.05) on the murein composition, although some muropeptides did not seem to be affected by the treatment. Each treatment influenced differently the relative percentage and number of muropeptides. There was a significant (P < or = 0.05) correlation between the reduction of intracellular ATP and increase in extracellular ATP following treatment of the cells with oregano oil. The reduction of intracellular ATP was even more important when essential oil was combined with irradiation. Also, irradiation alone of S. aureus induced a significant decrease (P < or = 0.05) of the internal ATP and a significant increase (P < or = 0.05) of the external ATP. However, no significant difference (P > 0.05) was observed in ATP concentrations between different radiation doses. Transmission electron microscopic observation revealed that oregano oil and irradiation have an effect on cell wall structure.
- Published
- 2010
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