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United States Department of Agriculture

Agricultural Research Service

Research Project: PATHOGEN PERSISTENCE AND PROCESSING OPTIMIZATION FOR ELIMINATION IN FOODS

Location: Food Safety and Intervention Technologies

Title: Evaluation of beef trim sampling methods for detection of Shiga toxin-producing Escherichia coli (STEC)

Authors
item Phebus, Randall -
item Luchansky, John
item Porto Fett, Anna
item Thippareddi, Harshavardhan -
item Singh, Manpreet -
item Sullivan, Rachel -
item Hettenbach, Susan -
item Wolf, John -
item Paddock, Casey -
item Baumann, Nicholas -
item Sevart, Nicholas -
item Minto, Michael -
item Milke, Donka -
item Marx, David -
item Harper, Nigel -
item Senecal, Andre -

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 28, 2013
Publication Date: July 28, 2013
Citation: Phebus, R., Luchansky, J.B., Porto Fett, A.C., Thippareddi, H., Singh, M., Sullivan, R.R., Hettenbach, S.M., Wolf, J., Paddock, C., Baumann, N., Sevart, N., Minto, M., Milke, D.T., Marx, D.B., Harper, N., Senecal, A. 2013. Evaluation of beef trim sampling methods for detection of Shiga toxin-producing Escherichia coli (STEC). Meeting Abstract. 76:81 (P1-43), International Association of Food Protection Annual Meeting, Charlotte, North Carolina, 7-28 to 7-31, 2013.

Technical Abstract: Presence of Shiga toxin-producing Escherichia coli (STEC) is a major concern in ground beef. Several methods for sampling beef trim prior to grinding are currently used in the beef industry. The purpose of this study was to determine the efficacy of the sampling methods for detecting STEC in beef trims. A six-strain STEC cocktail was inoculated onto a 908-g piece of beef trim and placed in a predetermined quadrant of the combo bin. Combo bins were broken into 27 quadrants (9 on the bottom, middle and top layers each). Sampling methods consisted of: The N-60 (industry standard method) and N-90 methods as described by the USDA (375 g composite sample), N-60 drill method (375 g composite sample), Cozzini core sampler (375 g composite sample), and purge (beef trim exudate, 375 mL sample) sampling methods. Meat was combined with 1.5 L of mEHEC enrichment medium and incubated at 42 deg C for 18 h. Samples were then processed and PCR was used to determine the presence of STEC. Purge sampling was the most effective method, with 13/14 positive samples. Cozzini corer, N-60 drill, N-60 and N-90 methods resulted in 11/14, 9/14, 7/14 and 7/14 samples being positive for STEC, respectively. The purge sampling and the Cozzini corer methods were superior compared to other methods for sampling beef trim for detection of STEC. The N-60 and N-90 sampling methods were effective for the top and middle layers, but only 3/12 samples were positive for bottom layer samples. It is not surprising that N-60 and N-90 was not effective with the bottom layer because typical sampling only involves cutting meat on the top of a combo bin. This research shows that purge and Cozzini corer methods are effective methods to sample for STEC in beef trim.

Last Modified: 7/22/2014