Silagyi Karen, Kim Shin-Hee, Lo Y Martin, Wei Cheng-i
Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA.
Food Microbiol. 2009 Aug;26(5):514-9. doi: 10.1016/j.fm.2009.03.004. Epub 2009 Mar 18.
Multistate outbreaks of Escherichia coli O157:H7 infections through consumption of contaminated foods including produce products have brought a great safety concern. The objectives of this study were to determine the effect of biofilm and quorum sensing production on the attachment of E. coli O157:H7 on food contact surfaces and to evaluate the transfer of the pathogen from the food contact to various food products. E. coli O157:H7 produced maximum levels of AI-2 signals in 12 h of incubation in tested meat, poultry, and produce broths and subsequently formed strong biofilm in 24 h of incubation. In general, E. coli O157:H7 formed stronger biofilm on stainless steel than glass. Furthermore, E. coli O157:H7 that had attached on the surface of stainless steel was able to transfer to meat, poultry, ready-to-eat deli, and produce products. Strong attachment of the transferred pathogen on produce products (cantaloupe, lettuce, carrot, and spinach) was detected (>10(3) CFU/cm2) even after washing these products with water. Our findings suggest that biofilm formation by E. coli O157:H7 on food contact surfaces can be a concern for efficient control of the pathogen particularly in produce products that require no heating or cooking prior to consumption.
通过食用包括农产品在内的受污染食品引发的大肠杆菌O157:H7感染的多州疫情引起了极大的安全担忧。本研究的目的是确定生物膜和群体感应产生对大肠杆菌O157:H7在食品接触表面附着的影响，并评估病原体从食品接触表面向各种食品的转移情况。在测试的肉类、家禽和农产品肉汤中培养12小时后，大肠杆菌O157:H7产生了最高水平的AI-2信号，随后在培养24小时后形成了强大的生物膜。一般来说，大肠杆菌O157:H7在不锈钢上形成的生物膜比在玻璃上更强。此外，附着在不锈钢表面的大肠杆菌O157:H7能够转移到肉类、家禽、即食熟食和农产品上。即使用水冲洗这些产品后，也检测到转移的病原体在农产品（哈密瓜、生菜、胡萝卜和菠菜）上有很强的附着（>10(3) CFU/cm2）。我们的研究结果表明，大肠杆菌O157:H7在食品接触表面形成生物膜可能是有效控制该病原体的一个问题，特别是在食用前无需加热或烹饪的农产品中。
