The goal of the project was to identify chemical and enzymatic agents that can effectively
degrade EHEC cell surface components that are critical to biofilm formation. With these
effective measures we can detach and de-clump EHEC cells adhered to the surface of beef 3
processing equipment in order to increase the efficiency and warrant the success of cleaning
and/or sanitizing treatments in the beef processing environment.
Findings: The formation of biofilm by the members of Enterohemorrhagic Escherichia coli (EHEC) involves at least two of their cell surface components, curli and cellulose. The curli fibers assist the cells in adhesion to solid surfaces, and cells with the fibers have been shown to have a better ability to interact with their contact surfaces. Cellulose, nevertheless, offers mechanical and chemical protection to EHEC cells. It plays a structural role in conferring mechanical strength to biofilm. When curli and cellulose are co-expressed by the cells of EHEC, a matrix of tightly packed cells is covered in a well-structured hydrophobic network. This network is extremely important in the persistence of EHEC on various surfaces.<P>
This study evaluated several enzymatic and chemical agents for their abilities to degrade cellulose and curli produced by EHEC cells, namely cellulase, protease, acetic acid, and lactic acid, as well as two commercial detergents, Quorum Yellow and Zep Formula 7961TM. All evaluated agents reduced the amounts of cellulose and curli produced by EHEC cells, even though some of the treatments were more effective than others. The evaluated agents also effectively controlled biofilm formation on a beef processing material in a laboratory setting.