Study on attenuation of Escherichia coli 0157 with a combination of essential oil of spices.

大肠杆菌0157具有高度感染性，并产生导致出血性结肠炎和溶血性尿毒症综合征的verocytotoxin。由于用抗生素治疗0157感染的报道增加了毒素基因的表达，因此建立有效的治疗方法是当务之急。本研究的目的是建立大肠杆菌的减毒方法。coli 0157中添加不同种类的香料精油，观察了不同香料对大肠杆菌产毒的影响。coli 0157，多香果对verocytotoxin的产生有较强的抑制作用。经分离、鉴定，其有效成分为丁香酚。丁香酚对病原菌产生Verocytotoxin 1和Verocytotoxin 2有抑制作用。研究了不同香辛料对E. coli 0157，生姜对病菌的耐酸性有较强的抑制作用。β-蒎烯、柠檬烯、丁香酚和生姜提取物的组合对于减少病原体的数量、抑制verocytotoxin的产生并降低耐酸性非常有效。

Escherichia coli 0157 has a highly infectious ability and produces verocytotoxin that causes hemorrhagic colitis and hemolytic uremic syndrome. Since therapy for 0157 infections with antibiotics is reported to increase expression of the toxin genes, establishing an effective treatment is a priority. The purpose of this study is the establishment of attenuation of E. coli 0157 with a combination of essential oils of spices.When we examined the effects of various spices on production of verocytotoxin by E. coli 0157, allspice showed a high suppressive effect on the verocytotoxin production. The effective component was isolated and then identified to be eugenol. Eugenol showed a suppressive effect on production of verocytotoxin 1 and 2 by the pathogen. When we examined the effects of various spices on acid- tolerance of E. coli 0157, ginger showed a high ability to reduce the acid-tolerance of the pathogen. A combination of β-pinene, limonene, eugenol, and ginger extract was highly effective on decreasing the population of the pathogen, suppressing the verocytotoxin-productivity, and reducing the acid- tolerance.