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United States Department of Agriculture

Agricultural Research Service

Title: Comparison of Petrifilm and Chromagar Ecc for Isolation of E. Coli from Chicken

Authors
item Bailey, Joseph
item Cray, Paula
item Berrang, Mark
item Plumblee, Jodie

Submitted to: International Association for Food Protection
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2005
Publication Date: July 15, 2005
Citation: Bailey, J.S., Cray, P.J., Berrang, M.E., Plumblee, J. 2005. Comparison of petrifilm and chromagar ecc for isolation of e. coli from chicken [abstract].International Association for Food Protection. 171:T4-08.

Technical Abstract: Generic E. coli is frequently recovered from processed broiler chickens, and FSIS is requiring meat and poultry slaughter plants to test carcasses for generic E. coli as an indicator of the adequacy of the plant's process control for fecal contamination. The majority of E. coli enumeration in the poultry and meat industries currently uses Petrifilm as the plating medium of choice. The objective of the current study was to determine if different subpopulations of E. coli were selected for by Petrifilm in comparison to ChromAgar ECC, a chromogenic medium for isolation of E. coli, and to compare the relative effectiveness of these two media to enumerate generic E. coli from processed broiler chicken rinsates. Rinse samples of broiler chickens taken from the processing line immediately after the picker or after the chill tank from eight processing plants were transported to the laboratory and sampled within 24 hr. Serial dilutions of the rinses were plated on Petrifilm and ChromAgar, and plates were incubated for 24 and 48 hr before counts were determined. Selected colonies were stored to compare antimicrobial resistance profiles and PFGE patterns. No significant difference in E. coli counts (Log 2.58 vs Log 2.49) were found between Petrifilm and ChromAgar. However, analysis of antibiotic resistance profiles and PFGE patterns indicates that the two plating media select for different subpopulations of E. coli. In general, ChromAgar selected for E. coli which had more antibiotic resistance. Further studies are required to determine the origins and significance of the different E. coli populations.

Last Modified: 4/20/2014
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