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

Arch Microbiol. 2013 Aug;195(8):587-93. doi: 10.1007/s00203-013-0907-5. Epub 2013 Jun 23.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Bacterial Load
  • Culture Media
  • Cymenes
  • Hot Temperature
  • Hydrogen-Ion Concentration
  • Meat
  • Microbial Sensitivity Tests
  • Microbial Viability
  • Monoterpenes / pharmacology*
  • Oils, Volatile / pharmacology*
  • Origanum
  • Sodium Chloride / pharmacology
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / growth & development
  • Staphylococcus aureus / physiology*

Substances

  • Culture Media
  • Cymenes
  • Monoterpenes
  • Oils, Volatile
  • origanum oil
  • Sodium Chloride
  • carvacrol