title: Quantitative microbial risk assessment for Staphylococcus aureus in natural and processed cheese in Korea.
abstract: This study quantitatively assessed the microbial risk of Staphylococcus aureus in cheese in Korea. The quantitative microbial risk assessment was carried out for natural and processed cheese from factory to consumption. Hazards for S. aureus in cheese were identified through the literature. For exposure assessment, the levels of S. aureus contamination in cheeses were evaluated, and the growth of S. aureus was predicted by predictive models at the surveyed temperatures, and at the time of cheese processing and distribution. For hazard characterization, a dose-response model for S. aureus was found, and the model was used to estimate the risk of illness. With these data, simulation models were prepared with @RISK (Palisade Corp., Ithaca, NY) to estimate the risk of illness per person per day in risk characterization. Staphylococcus aureus cell counts on cheese samples from factories and markets were below detection limits (0.30-0.45 log cfu/g), and pert distribution showed that the mean temperature at markets was 6.63°C. Exponential model [P=1 - exp(7.64×10(-8) × N), where N=dose] for dose-response was deemed appropriate for hazard characterization. Mean temperature of home storage was 4.02°C (log-logistic distribution). The results of risk characterization for S. aureus in natural and processed cheese showed that the mean values for the probability of illness per person per day were higher in processed cheese (mean: 2.24×10(-9); maximum: 7.97×10(-6)) than in natural cheese (mean: 7.84×10(-10); maximum: 2.32×10(-6)). These results indicate that the risk of S. aureus-related foodborne illness due to cheese consumption can be considered low under the present conditions in Korea. In addition, the developed stochastic risk assessment model in this study can be useful in establishing microbial criteria for S. aureus in cheese.
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Heeyoung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Seoul 135-710, Korea.
authors.forename: Kyunga
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Oral Microbiology, College of Dentistry, Wonkwang University, Iksan, Jeonbuk 570-749, Korea. Electronic address: kheechoi@wonkwang.ac.kr.
authors.forename: Kyoung-Hee
authors.initials: KH
authors.lastname: Choi
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea. Electronic address: yyoon@sookmyung.ac.kr.
authors.forename: Yohan
authors.initials: Y
authors.lastname: Yoon
mesh_terms: D002611:Cheese / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000175:diagnosis / Q000453:epidemiology*; D008962:Models, Theoretical; D056910:Republic of Korea / Q000453:epidemiology; D018570:Risk Assessment; D013211:Staphylococcus aureus / Q000254:growth & development / Q000302:isolation & purification*; D013696:Temperature
keywords: Staphylococcus aureus; cheese; exposure assessment; microbial risk assessment; risk characterization