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United States Department of Agriculture

Agricultural Research Service


item Flores, Rolando
item Stewart, Tod
item Tamplin, Mark

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2002
Publication Date: 6/30/2002
Citation: Flores, R.A., Stewart, T.E., Tamplin, M.L. 2002. Distribution of escherichia coli o157:h7 in ground meat resulting from a laboratory-scale grinder. International Association of Food Protection Abstract # P182.

Interpretive Summary:

Technical Abstract: Epidemiological reports link contaminated meat grinders to human illnesses caused by Escherichia coli O157:H7 and Salmonella spp. This research was designed to study the distribution of E. coli O157:H7 in ground beef when a contaminated beef trim was introduced into a batch of uncontaminated beef prior to processing in a laboratory grinder. Beef trim was inoculated with a rifampacin-resistant strain of E. coli O157:H7 at seven inoculum levels (1.0E06, 1.0E05, 1.0E04, 1.0E03, 1.0E02, 1.0E01, and 1.0E00 total CFU). The highest E. coli O157:H7 concentration in the ground beef corresponded to the inoculated ground trim or the point where the pathogenic organisms were inserted into the grinding batch. For all inoculum levels, the pathogen concentration in the ground beef was a function of the initial inoculum level. A decreasing distribution of the pathogen was observed in the ground beef following the grinding of the contaminated trim. The location and concentration of E. coli O157:H7 retained in the grinder was proportional to the inoculum level. To extrapolate the distribution patterns observed in this study to a plant level operation, large-scale trials need to be conducted. However, these results show that the amount of E. coli O157:H7 on a single trim is distributed over a quantity of ground beef larger than the original trim size, and that E. coli O157:H7 is retained in parts of the grinder. Consequently, sanitation schedules should consider the potential accumulation of pathogens in grinder parts, and the design of grinders should attempt to minimize accumulation and maximize sanitation.

Last Modified: 10/19/2017
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