title: Lack of induction of direct protection or cross-protection in Staphylococcus aureus by sublethal concentrations of Origanum vulgare L. essential oil and carvacrol in a meat-based medium.
abstract: The capacity of Origanum vulgare L. essential oil (OVEO) and its majority compound, carvacrol (CAR), to induce direct tolerance and cross-tolerance in Staphylococcus aureus against high temperature (45 °C), lactic acid (pH 5.2) and NaCl (10 g/100 mL) was assessed. Overnight exposure of S. aureus to sublethal concentrations (1/2 MIC, 1/4 MIC) of either OVEO or CAR in meat broth revealed no induction of direct protection. S. aureus cells pre-adapted to OVEO or CAR showed no induction of cross-protection to high temperature, lactic acid or NaCl. Cells subjected to 24 h cycles of adaptation in increasing amounts (1/2 MIC to 2 × MIC) of OVEO or CAR showed no increase in direct tolerance. These results revealed a lack of induction of direct protection or cross-protection in S. aureus exposed to sublethal amounts of OVEO or CAR in meat-based broth, as determined by monitoring cell survival and growth behavior.
authors.affiliation: Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Silva da Luz
authors.forename: Nelson Justino
authors.initials: NJ
authors.lastname: Gomes Neto
authors.forename: Adassa Gama
authors.initials: AG
authors.lastname: Tavares
authors.forename: Pollyana Campos
authors.initials: PC
authors.lastname: Nunes
authors.forename: Marciane
authors.initials: M
authors.lastname: Magnani
authors.forename: Evandro Leite
authors.initials: EL
authors.lastname: de Souza
mesh_terms: D000222:Adaptation, Physiological; D058491:Bacterial Load; D003470:Culture Media; D000081007:Cymenes; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008460:Meat; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D039821:Monoterpenes / Q000494:pharmacology*; D009822:Oils, Volatile / Q000494:pharmacology*; D031341:Origanum; D012965:Sodium Chloride / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*
chemical_list: D003470:Culture Media; D000081007:Cymenes; D039821:Monoterpenes; D009822:Oils, Volatile; C029292:origanum oil; D012965:Sodium Chloride; C073316:carvacrol