Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/24/2002
Publication Date: N/A
Technical Abstract: Pathogenic Escherichia coli are defined as those E. coli strains that are capable of causing diarrhoeal disease in humans. Subdivision of the pathogenic forms is made on the basis of the mechanism underlying the illness. Presently, four types of pathogenic E. coli have been implicated in foodborne disease outbreaks: enteropathogenic, enterotoxigenic, enteroinvasive, and enterohaemorrhagic strains such as E. coli O157:H7. Strains of E. coli may be differentiated from one another serologically on the basis of somatic, flagellar, and capsular antigens. This serological distinction among strains is a very important tool applied for tracking clinical isolates back to their food sources in foodborne diseases outbreaks. Raw foods of animal origin may be contaminated by E. coli serotype O157:H7 through fecal contact during slaughter or milking procedures. Prevention of fecal contamination during the recovery and processing of foods derived from animals is paramount in controlling foodborne infections with this pathogen. Although E. coli O157:H7 possesses a number of virulence genes and is relatively acid tolerant, it does not have an unusual heat resistance; the D-values in beef range from 20.4 min at 55C to 0.16 min at 65C. As detailed in this presentation, researchers have developed risk assessment models that identify the occurrence and concentration of the pathogen at specific points from farm-to-table and assist regulatory agencies in reviewing and refining a risk reduction strategy for E. coli O157:H7 in ground beef.