Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil.
Arch Microbiol. 2013 Aug;195(8):587-93. doi: 10.1007/s00203-013-0907-5. Epub 2013 Jun 23.
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.
研究了牛至草精油（OVEO）及其主要成分香芹酚（CAR）对金黄色葡萄球菌在高温（45°C）、乳酸（pH5.2）和 NaCl（10 g/100 mL）下直接诱导耐受和交叉耐受的能力。在肉汤中，金黄色葡萄球菌过夜暴露于亚致死浓度（1/2 MIC、1/4 MIC）的 OVEO 或 CAR 下，未诱导直接保护。经 OVEO 或 CAR 预适应的金黄色葡萄球菌细胞对高温、乳酸或 NaCl 没有诱导交叉保护。经 24 小时的适应周期，在肉汤中以递增的量（1/2 MIC 至 2×MIC）适应 OVEO 或 CAR 的细胞，其直接耐受性没有增加。这些结果表明，金黄色葡萄球菌在肉汤中暴露于亚致死量的 OVEO 或 CAR 时，没有诱导直接保护或交叉保护，这是通过监测细胞存活和生长行为来确定的。
