期刊
FOOD CONTROL
卷 62, 期 -, 页码 257-263出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.foodcont.2015.10.049
关键词
Staphylococcus aureus; Tea tree oil; Inhibition; Milk; Staphylococcal enterotoxin
资金
- National Nature Science Foundation of China [31271951]
- China Postdoctoral Science Foundation [2013M530142]
- Program for New Century Excellent Talents in University [NCET-13-0245]
Staphylococcus aureus (S. aureus), a major food-borne pathogen, causes disease in mammalian hosts by producing a wide variety of exoproteins, such as alpha-hemolysin and staphylococcal enterotoxins. Tea tree oil (TTO), an essential oil, has broad-spectrum antimicrobial activity. The objectives of this study were to evaluate the inhibitory effects of TTO on S. aureus growth and on alpha-hemolysin, enterotoxins A and B production. In this study, the effect of TTO on S. aureus growth in laboratory medium and pasteurized milk was determined by time-kill assays. Treatment with half of minimal inhibitory concentration (MIC) of TTO demonstrated very little or no reduction in numbers of viable ATCC 29213 cells; however, 1 x MIC of TTO reduced the viable cell count more noticeably, and 2 x MIC of TTO demonstrated an even greater reduction in the viable cell count, both in TSB and milk. The influence of TTO on enterotoxins was determined by real-time reverse transcriptase-PCR (real-time RT-PCR), a hemolysis assay, Western blot and a tumor necrosis factor alpha (TNF-alpha) assay. The real-time RT-PCR results revealed that the transcription of genes encoding alpha-hemolysin, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) were down regulated after S. aureus was exposed to TTO (0.0625 mg/mL-0.5 mg/mL). The hemolytic assay showed that S. aureus hemolytic activity was inhibited by subinhibitory concentrations of TTO (0.0625 mg/mL-0.5 mg/mL). The Western blot assay identified that the production of the three virulence factors was inhibited by TTO (0.0625 mg/mL-0.5 mg/mL). Moreover, the enzyme linked immunosorbent assay (ELISA) demonstrated that TNF-alpha production was suppressed by TTO treatment in RAW264.7 cells stimulated by S. aureus supernatant containing staphylococcal enterotoxins (SEs). (C) 2015 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据