Comparison of processing parameters in large and small scale beef processing plants and their impact on Escherichia coli prevalence

Sydney Cooper Corkran, Purdue University


Further research is necessary to overcome foodborne illnesses due to pathogens associated with local and regional foods as consumer demand for local beef continues to grow. Escherichia coli has been confirmed in 113 outbreaks in beef products from 2000-2014 (CDC, 2016a). While Shiga Toxin Escherichia coli (STEC) O157 and non-O157 can be attributed to approximately 175,905 illnesses annually in the United States (Scallan et al., 2011). To bridge the gap between large and small beef processing plants, the current study evaluates the operational and equipment differences in large and small plants, which contribute to the efficacy of interventions within each plant and their impact on the prevalence of aerobic bacteria, total coliforms, and E. coli. We observed that small class II plants achieved the greatest log reduction, 0.92 log10CFU/cm2, however, were simultaneously finished with the highest generic E. coli populations during carcass chilling. Our chromogenic agar results observed E. coli O157 and STEC to be prevalent at higher rates during large plant sampling (21/38 positive processing locations) while E. coli O157 was detected in 32/38 processing locations. Molecular characterization of cultured E. coli O157 and STEC isolates confirmed 19 STEC isolates. Serotyping identified 57.89% of isolates to be E. coli O103, while 0.05% were identified as E. coli O26. Food safety culture surveys identified a need for greater education and training for management and employees in small processing plants. Thus, highlighting the importance of effective communications in food safety training to attain a thorough understanding of fundamental food safety principles and practices. Understanding and enforcement of fundamental food safety principles is critical to bridging the gap between large and small beef processing plants. The current study’s holistic analysis of beef processing is crucial to understanding the multitude of variables, which impact food safety within the beef slaughter facilities. Greater insight to the differences in operational capabilities and employee training, between large and small beef processors, will propel beef safety research forward and provide a greater understanding of the necessities required to mitigate foodborne illness.




Singh, Purdue University.

Subject Area

Food Science|Animal sciences

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