Title: Characterization of E. coli O157:H7 strains resulting from contamination of raw beef trim during high event periods
Authors: Arthur TM, Bono JL, Kalchayanand N
Journal: Appl Environ Microbiol
Accepted date: 2013 Oct 31
Interpretive summary: The development and implementation of effective antimicrobial interventions by the beef processing industry in the United States has dramatically reduced the incidence of beef trim contamination by Escherichia coli O157:H7. However, individual processing plants still experience sporadic peaks in contamination rates where multiple contamination of finished product clustered in a short time frame. These peaks have been referred to as “High Event Periods” (HEP) of contamination. The results reported here detail the characterization of E. coli O157:H7 isolates from twenty-one HEP across multiple companies and processing plants to gain insight regarding the mechanisms causing these incidents. Through these analyses, it was determined that individual HEP show little to no diversity of strain type. Hence, each HEP has one strain type that makes up most if not all of the contamination. This is shown to differ from the high strain diversity of incoming pathogen load found on the hides of cattle entering processing plants which is assumed to be the source of carcass contamination. Results of this study pose a potential challenge to the current model for finished product contamination during beef processing.
Publication date: 2014 Jan
Related projects: Pathogen Mitigation in Livestock and Red Meat Production