Production of biofilm and quorum sensing by Escherichia coli O157:H7 and its transfer from contact surfaces to meat, poultry, ready-to-eat deli, and produce products.

ABSTRACT

Multistate outbreaks of Escherichia coli O157H7 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 O157H7 on food contact surfaces and to evaluate the transfer of the pathogen from the food contact to various food products. E. coli O157H7 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 O157H7 formed stronger biofilm on stainless steel than glass. Furthermore, E. coli O157H7 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 O157H7 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.