• Food Science and Biotechnology
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• v.18 no.1
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• pp.137-142
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• 2009

One of the most important aspects of conducting this microbial risk assessment (MRA) is determining the model in microbial behaviors in food systems. However, to fully these modeling, large expenditures or newly laboratory experiments will be spent to do it. To overcome these problems, it has to be considered to develop the new strategies that can be used data in the published literatures. This study is to show whether or not the data set from the published experimental data has more value for modeling for MRA. To illustrate this suggestion, as example of data set, 4 published Salmonella survival in Cheddar cheese reports were used. Finally, using the GInaFiT tool, survival was modeled by nonlinear polynomial regression model describing the effect of temperature on Weibull model parameters. This model used data in the literatures is useful in describing behavior of Salmonella during different time and temperature conditions of cheese ripening.

• Food Science of Animal Resources
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• v.35 no.5
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• pp.674-682
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• 2015

The objective of this study was to evaluate the risk of illness from Campylobacter spp. on ham. To identify the hazards of Campylobacter spp. on ham, the general characteristics and microbial criteria for Campylobacter spp., and campylobacteriosis outbreaks were investigated. In the exposure assessment, the prevalence of Campylobacter spp. on ham was evaluated, and the probabilistic distributions for the temperature of ham surfaces in retail markets and home refrigerators were prepared. In addition, the raw data from the Korea National Health and Nutrition Examination Survey (KNHNES) 2012 were used to estimate the consumption amount and frequency of ham. In the hazard characterization, the Beta-Poisson model for Campylobacter spp. infection was used. For risk characterization, a simulation model was developed using the collected data, and the risk of Campylobacter spp. on ham was estimated with @RISK. The Campylobacter spp. cell counts on ham samples were below the detection limit (<0.70 Log CFU/g). The daily consumption of ham was 23.93 g per person, and the consumption frequency was 11.57%. The simulated mean value of the initial contamination level of Campylobacter spp. on ham was −3.95 Log CFU/g, and the mean value of ham for probable risk per person per day was 2.20×10⁻¹². It is considered that the risk of foodborne illness for Campylobacter spp. was low. Furthermore, these results indicate that the microbial risk assessment of Campylobacter spp. in this study should be useful in providing scientific evidence to set up the criteria of Campylobacter spp..

• Food Science of Animal Resources
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• v.32 no.1
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• pp.118-124
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• 2012

This study was conducted for quantitative microbial risk assessment (QMRA) of Clostridium perfringens with consumption on ham and sausage products in Korea, according to Codex guidelines. Frame-work model as product-retail-consumption pathway composed with initial contamination level, the time and temperature in distributions, and consumption data sets for ham and sausage products and also used the published predictive growth and dose-response models for Cl. perfringens. The simulation model and formulas with Microsoft@ Excel spreadsheet program using these data sets was developed and simulated with @RISK. The probability of foodborne disease by Cl. perfringens with consumption of the ham and sausage products per person per day was estimated as $3.97{\times}10^{-11}{\pm}1.80{\times}10^{-9}$. There were also noted that limitations in this study and suggestion for development of QMRA in the future in Korea.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.579-592
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• 2017

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 ${\times}$ 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 (${\alpha}=2.21{\times}10^{-1}$, $N_{50}=6.85{\times}10^7$). The results of risk characterization for non-EHEC E. coli in natural and processed cheese were $1.36{\times}10^{-7}$ and $2.12{\times}10^{-10}$ (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.

• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.340-345
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• 1997

This study was undertaken to evaluate microbial risk degree of some processed foods in Korea. In this study the data on the outbreak of foodborne diseases during recent 18 years (1976-1989, 1993-1996. 8) were analyzed. The most frequently isolated pathogens were Salmonella (36.9%); followed vibrio (22.0%), Staphylococcus (15.7%) and Escherichia coli (13.3%). Outbreak rate of Staphylococcus, Vibrio, E. coli and Salmonella, was 33.0%, 23.5%, 17.5% and 17.1%, respectively. Overall risk degree of pathogens by fatality rate, outbreak rate and pathogen amount for foodborne outbreak was Clostridium, 5, Staphylococcus and Vibrio, 4, Salmonella and E. coli, 3. Based on foodborne pathogens, the risk degree of raw seafoods, raw eggs and processed seafoods were 4, and those of raw meats, Doshiraks and milk products were 3. Also, based on processing characteristics of foods, the risk degree of surimi-based imitation crab was 3. Foods of the highest actual risk degree were raw seafoods and raw eggs (16); followed raw meats (15), surimi-based imitation crab (12), Doshirak (9) and milk products (6).

• Restorative Dentistry and Endodontics
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• v.46 no.2
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• pp.19.1-19.12
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• 2021

Objectives: The purpose of this study was to conduct a systematic review and meta-analysis of in vitro studies regarding the effectiveness of reciprocating and rotary instrumentation on microbial reduction in root canals. Materials and Methods: PubMed, Scopus, Web of Science, the Cochrane Library, and the gray literature were searched through December 2019. Studies comparing the influence of reciprocating and rotary instrumentation on the removal of microorganisms from root canals that quantified the antimicrobial effect were included. Data extraction was completed using a systematic form for data collection. The risk of bias of the studies was evaluated. Standardized mean differences (SMDs) and confidence intervals (CIs) were calculated using a random effects meta-analysis. Results: Seventeen in vitro studies were included in this systematic review, of which 7 provided adequate data for inclusion in the meta-analysis. Both reciprocating and rotary systems were similarly effective in reducing the microbial load in infected root canals (SMD [95% CI], 0.0481 [-0.271, 0.367]). Three studies showed a low risk of bias, whereas most of the studies (82%) presented a medium risk. Conclusions: Although both techniques decrease the microbial content (with reductions of 23.32%-88.47% and 23.33%-89.86% for reciprocating and rotary instrumentation, respectively), they are not able to provide complete disinfection of root canals.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2005.11a
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• pp.159-173
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• 2005

• Journal of Dairy Science and Biotechnology
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• v.29 no.2
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• pp.69-73
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• 2011

Food borne pathogens are a growing concern for human health and food safety throughout the world. Milk and dairy products are commonly associated with spoilage or contamination from a wide variety of physical, microbial, and chemical hazardous. Microbiological risk analysis consists of three components: risk assessment, risk management, and risk communication, and overall objective of this process is ultimately public health protection. The microbiological risk assessment is useful tool to evaluate food safety as it is based on a scientific approach. In addition risk assessment process includes quantitative estimation of the probability of occurrence of microbial hazards to evaluate more accurate human exposure. The aim of this study is to review the microbiological risk assessment on the prevalence of bacterial foodborne pathogens in milk and dairy products.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.225-236
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• 2005

The protection of public health In wastewater reclamation and reuse is one of the most important issues. Monitoring data of Escherichia coli were collected from paddy rice plots in 2003 and 2004 experiments. Five treatments were used and each one was triplicated to evaluate the changes of E. coli: surface water, biofilter effluent (secondary level), UV-disinfected water and pond treatment. Microbial risk was quantified to assess human health risk by exposure to E. coli in paddy rice plots, which were irrigated with reclaimed wastewater. Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion that may occur to farmer and neighbor children. Monte-Carlo analysis (10,000 trials) was used to estimate the risk characterization of uncertainty. In the following analysis, two scenarios were related to the reduction of risk against direct ingestion and exposure times. Scenarios A and B were assumed that the risk was 1,000 and 10,000 times lower than direct ingestion.'Golfers were assumed to be 0.001 L of reclaimed water by contact with balls and their cloths. Opportunity of contact in paddy rice field with pathogens was more frequent than handing golf balls, because of agricultural activity was practiced in ponded water in paddy rice culture. As a result of microbial risk assessment using total data of experimental period, risk value of E. coli in 2003 and 2004 experiment ranged from $10^{-5}$ to $10^{-8}$ and $10^{-4}$ to $10^{-8}$, respectively. The risk values in biofilter effluent irrigation was the highest, which is $10^{-4}$ in 2003 and $10^{-5}$ in 2004 experiments with scenario A. Ranges of $10^{-6}$ to $10^{-8}$ were considered at reasonable levels of risk for communicable disease transmission from environmental exposure and the risk value above $10^{-4}$ was considered to be attributable to the risk of infection. Irrigation with UV-disinfected water in the paddy field during the agricultural Period showed significantly lower microbial risk than others, and their levels of risk value were within the range of actual paddy rice field with surface water.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.373-376
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• 2010

The objective of this study was to present the proper probability distribution model based on the data obtained from surveys on domestic refrigerator food storage temperatures in home. Domestic refrigerator temperatures were determined as risk factors in foodborne disease outbreaks for microbial risk assessment (MRA). The temperature was measured by directly visiting 139 homes using a data logger from May to September of 2009. The overall mean temperature for all the refrigerators in the survey was $3.53{\pm}2.96^{\circ}C$, with 23.6% of the refrigerators measuring above $5^{\circ}C$. Probability distributions were also created using @RISK program based on the measured temperature data. Statistical ranking was determined by the goodness of fit (GOF, i.e., the Kolmogorov-Smirnov (KS) or Anderson-Darling (AD) test) to determine the proper probability distribution model. This result showed that the LogLogistic (-10.407, 13.616, 8.6107) distribution was found to be the most appropriate for the MRA model. The results of this study might be directly used as input variables in exposure evaluation for conducting MRA.