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United States Department of Agriculture

Agricultural Research Service

Title: Identification of Enterobacteriaceae and Related Organisms from Rinses of Eggs Collected During Processing in Commercial Shell Egg Processing Plants in the Southeastern United States

item Musgrove, Michael
item Jones, Deana
item Northcutt, Julie
item Cox, Nelson
item Harrison, Mark - UGA

Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2004
Publication Date: June 1, 2004
Citation: Musgrove, M.T., Jones, D.R., Northcutt, J.K., Cox Jr, N.A., Harrison, M.A. 2004. Identification of enterobacteriaceae and related organisms from rinses of eggs collected during processing in commercial shell egg processing plants in the southeastern united states [abstract]. Poultry Science. 82:157.

Technical Abstract: Since passage of the Egg Products Inspection Act in 1970, processing guidelines have been established to ensure that external and internal characteristics are favorably affected. However, less is known about safety of commercially processed shell eggs. In order to determine genus or species of enteric bacteria entering plants and persisting throughout processing, eggs were collected from three US commercial shell egg in-line processing plants on three separate visits. During every plant visit, 12 eggs were collected from each of 12 sites along the processing line: accumulator, pre-wash rinse, 1st washer, 2nd washer, sanitizing rinse, blower, oiler, check detection/scales, 2 egg grader packer lanes, re-wash belt entrance, and re-wash belt exit. Individual eggs were sampled by a rinse technique and rinsate was plated onto violet red bile glucose agar with overlay for the detection and enumeration of Enterobacteriaceae. From each positive plate, up to five colonies were randomly selected and isolated for further analysis. Using biochemical tests, isolates were identified to the genus or species level. A variety of genus-species were detected from the three plants. Sites for which the greatest numbers of isolates were identified were those collected from eggs during pre-processing (accumulator, pre-wash rinse) or eggs judged as dirty (re-wash belt entrance or exit). Sites yielding the least number of isolates were those during or at the end of processing. Escherichia coli and Enterobacter spp. were isolated from all of the nine plant visits. Other genera isolated from at least one of the three plants included Cedecea, Citrobacter, Erwinia, Hafnia, Klebsiella, Kluyvera, Leclercia, Morganella, Proteus, Providencia, Rahnella, Salmonella, and Serratia. Non-Enterobacteriaceae isolated and identified included Aeromonas, Chryseomonas, Listonella, Pseudomonas, Sphingobacterium, Vibrio, and Xanthomonas. As all of the genera and species were recovered less frequently from fully processed eggs than from unwashed or in-process eggs, these data indicate that US shell eggs are safer as a result of commercial processing procedures currently being used.

Last Modified: 4/22/2015