title: Specific expression of adherence-related genes in Escherichia coli O157:H7 strain EDL933 after heat treatment in ground beef.
abstract: In this study, the expression of particular stress- and virulence-associated genes of Escherichia coli O157:H7 strain EDL933 in ground beef was investigated using real-time PCR. Specific gene expression in the food matrix was found in combination with heat treatment. In contrast to a treatment at 37°C, treatment at 48°C for 10 min resulted in increased expression of the genes eae, hcpA, iha, lpfA, and toxB. Adherence to human intestinal HT-29 cells was enhanced in bacterial cells inoculated and heat treated in ground beef. The expression of gadE, which encodes a main regulator of the glutamate system of the acid response, was reduced under these conditions. However, expression of rpoS and recA, which are involved in the establishment of stress responses, and Shiga toxin genes was not significantly different under the same conditions.
authors: Department of Food Microbiology, Institute of Food Science and Biotechnology, Garbenstraße 28, University of Hohenheim, 70599 Stuttgart, Germany.
authors: T
authors: T
authors: Slanec
authors: H
authors: H
authors: Schmidt
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics*; D002417:Cattle; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D019453:Escherichia coli O157 / Q000235:genetics / Q000502:physiology*; D005516:Food Microbiology; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006358:Hot Temperature; D006801:Humans; D008461:Meat Products / Q000382:microbiology*; D013997:Time Factors