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Microbial Risk Assessment of Non-Enterohemorrhagic Escherichia coli in Natural and Processed Cheeses in Korea
Korean J. Food Sci. An. 2017;37:579-592
Published online August 31, 2017
© 2017 Korean Society for Food Science of Animal Resources

Kyungmi Kim1†, Heeyoung Lee, Soomin Lee, Sejeong Kim, Jeeyeon Lee, Jimyeong Ha, and Yohan Yoon*

Risk Analysis Research Center, Sookmyung Women’s University, Seoul 04310
1Department of Food and Nutrition, Sookmyung Women’s University, Seoul 04310, Korea
Correspondence to: Yohan Yoon
Department of Food and Nutrition, Sookmyung Women’s University, Seoul 04310, Korea
Tel: +82-2-2077-7585 Fax: +82-2-710-9479 E-mail:
†Kyungmi Kim and Heeyoung Lee are equally contributed.
Received June 9, 2017; Revised August 6, 2017; Accepted August 7, 2017.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
This study assessed the quantitative microbial risk of non-enterohemorrhagic Escherichia coli (EHEC). For hazard identification, hazards of non-EHEC E. coli in natural and processed cheeses were identified by research papers. Regarding exposure assessment, non-EHEC E. coli cell counts in cheese were enumerated, and the developed predictive models were used to describe the fates of non-EHEC E. coli strains in cheese during distribution and storage. In addition, data on the amounts and frequency of cheese consumption were collected from the research report of the Ministry of Food and Drug Safety. For hazard characterization, a doseresponse model for non-EHEC E. coli was used. Using the collected data, simulation models were constructed, using software @RISK to calculate the risk of illness per person per day. Non-EHEC E. coli cells in natural- (n=90) and processed-cheese samples (n=308) from factories and markets were not detected. Thus, we estimated the initial levels of contamination by Uniform distribution × Beta distribution, and the levels were -2.35 and -2.73 Log CFU/g for natural and processed cheese, respectively. The proposed predictive models described properly the fates of non-EHEC E. coli during distribution and storage of cheese. For hazard characterization, we used the Beta-Poisson model (α=2.21×10-1, N50=6.85×107). The results of risk characterization for non-EHEC E. coli in natural and processed cheese were 1.36×10-7 and 2.12×10-10 (the mean probability of illness per person per day), respectively. These results indicate that the risk of non-EHEC E. coli foodborne illness can be considered low in present conditions.
Keywords : microbial risk assessment, Escherichia coli, cheese, exposure assessment

August 2017, 37 (4)