• Food Engineering Progress
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• v.14 no.4
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• pp.316-321
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• 2010

The efficacy of the ozonated water (0.1, 0.2, 0.4, 0.6, and 1.0 ppm) in reducing the risk of food-borne disease was investigated in this study. After inoculation of Listeria monocytogenes (ATCC 19112), Salmonella enterica subsp. enterica biovar Typhimurium (ATCC 12598), Escherichia coli O157:H7 (ATCC 43890) to lettuce, spinach, and beef, inhibition effect with different washing concentrations, time, and methods with ozonated and tap water were evaluated. As a result, there were 2.16 to 3.85 log CFU/mL reduction in different foods and 7 log CFU/mL reduction on cutting boards after watering with ozonated water. Higher than 0.2 ppm of ozonated water treatment reduced the growth of food-borne disease bacteria with increasing washing time and ozone concentration. These results suggested that the ozonated water treatment effectively improved the microbiological quality and food safety.

• The Korean Journal of Food & Health Convergence
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• v.5 no.3
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• pp.35-40
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• 2019

In this study, general bacterial counts and coliform counts, which are hygienic indicator microorganisms, were tested for candy, chocolate, and jelly which are easily available and enjoyed around. After dropping each sample on the desk, indoors, and outdoors, it is immediately collected, or washed and collected to confirm the myth of the 3-second rule. Immediately after removing the wrapping paper, each sample was dropped on the desk, indoors, and outdoors, and after 3 seconds from the moment of contact with the surface, and then collected in a sample bag using sterilized sanitary gloves. After the same operation, each sample was rinsed for 5 seconds using sterilized sanitary gloves and sterilized distilled water, and then collected in a sample bag. The number of bacteria detected in non-washing candies was 41 CFU/g at outdoor and the number of bacteria detected in non-washing chocolate was 76 CFU/g at outdoor. The number of bacteria detected in non-washing jellies was 79 CFU/g at outdoor. Coliform group was not detected in all samples. This showed good results at the level of m = 10,000 or less, which is an allowable value suggested in the Food Code. Also, effect of washing on contaminated food was confirmed. This result is remarkably low compared with the microorganism specimens shown in Food Code, and it is confirmed that contamination occurs but not high value. Therefore, the myth of the 3-second rule is true compared to the figures based on Food Code. However, it showed the characteristics of bacteria that could survive and cross-contaminate on dry food surfaces and emphasized the importance of hygiene through food contact to unsanitary surfaces to minimize the risk of food poisoning.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.1
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• pp.81-89
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• 2021

Purpose: A steady increase in Clostridioides difficile enteritis (CDE) has been reported recently. CDE is associated with intestinal dysbiosis, and vitamin D receptors are known to play an important role in this microbial imbalance as immunological regulators. We investigated the difference in vitamin D levels between children with CDE and those with other acute infectious enteritis. Methods: This retrospective study was conducted on children below 18 years of age who visited the Gil hospital, underwent investigation to assess vitamin D levels, and had confirmed gastrointestinal infection between January 2015 and December 2018. Patients were divided into two groups: the "CDE group" (n=18) and the "other infectious enteritis group" (n=88); their clinical characteristics, other laboratory results, and vitamin D levels were analyzed. Results: There was no difference in gender, age, and seasonal distributions between the CDE and other infectious enteritis groups. Other laboratory results were not significantly different between two groups, excluding serum albumin level (4.52±0.45 g/dL vs. 4.31±0.28 g/dL, p=0.011). The mean 25-hydroxy vitamin D level in the CDE group was higher than that in the control group (18.75±8.11 ng/mL vs. 14.50±6.79 ng/mL, p=0.021). Conclusion: Vitamin D levels in the CDE group were lower than normal but higher than the other infectious enteritis group. These results suggested that CDE has a different mechanism or susceptibility associated with vitamin D in children, and even marginal changes in vitamin D levels can act as a risk factor for infection.

• Food Science and Industry
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• v.49 no.3
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• pp.55-61
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• 2016

Even though the food safety system in the United States is one of the best in the world, many millions of people become sick and thousands die from foodborne illnesses caused by any of a number of microbial pathogens and other contaminants. Large recalls of United States Department of Agriculture (USDA) and the Food Drug and Administration (US FDA)-regulated food products due to findings of E. coli O157:H7, Listeria, Salmonella, and other problems occur each year. As the US FDA Food Safety Modernization Act (FSMA) passed in 2011, FSMA will require food processing, manufacturing, shipping, and other regulated entities to conduct an analysis of the most likely safety hazards and to design and implement risk-based controls to reduce or eliminate these hazards. FSMA also mandates increased scrutiny of food imports, which account for a growing share of U.S. food consumption; food import shipments will have to be accompanied by documentation showing that they can meet safety standards that are at least equivalent to those in the U.S. On September 17, 2015, the US FDA published final rules for Preventive Controls for Human and Animal Food and, continuing into 2016, the US FDA intends to finalize the remaining five rules it has proposed to implement FSMA. Among these rules, this article will review and discuss Preventive Controls for Human Food Rule and its components, and suggest how to comply with these FSMA rules as foreign human food and ingredients suppliers to the US.

• Food Science of Animal Resources
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• v.41 no.2
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• pp.173-184
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• 2021

Clean labeling is emerging as an important issue in the food industry, particularly for meat products that contain many food additives. Among synthetic additives, nitrite is the most important additive in the meat processing industry and is related to the development of cured color and flavor, inhibition of oxidation, and control of microbial growth in processed meat products. As an alternative to synthetic nitrite, preconverted nitrite from natural microorganisms has been investigated, and the applications of pre-converted nitrite have been reported. Natural nitrate sources mainly include fruits and vegetables with high nitrate content. Celery juice or powder form have been used widely in various studies. Many types of commercial starter cultures have been developed. S. carnosus is used as a critical nitrate reducing microorganism and lactic acid bacteria or other Staphylococcus species also were used. Pre-converted nitrite has also been compared with synthetic nitrite and studies have been aimed at improving utilization by exploiting the strengths (positive consumer attitude and decreased residual nitrite content) and limiting the weaknesses (remained carcinogenic risk) of pre-converted nitrite. Moreover, as concerns regarding the use of synthetic nitrites increased, research was conducted to meet consumer demands for the use of natural nitrite from raw materials. In this report, we review and discuss various studies in which synthetic nitrite was replaced with natural materials and evaluate pre-converted nitrite technology as a natural curing approach from a clean label perspective in the manufacturing of processed meat products.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3631-3640
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• 2022

Uranium mill tailing ponds (UMTPs) are risk source of debris flow and a critical source of environmental U and Rn pollution. The technology of microbial induced calcium carbonate precipitation (MICP) has been extensively studied on reinforcement of UMTs, while little attention has been paid to the effects of MICP on U & Rn release, especially when incorporation of metakaolin and bacillus subtilis (MBS). In this study, the reinforcement and U & Rn immobilization role of MBS -MICP solidification in different grouting cycle for uranium mill tailings (UMTs) was comprehensively investigated. The results showed that under the action of about 166.7 g/L metakaolin and ~50% bacillus subtilis, the solidification cycle of MICP was shortened by 50%, the solidified bodies became brittle, and the axial stress increased by up to 7.9%, and U immobilization rates and Rn exhalation rates decrease by 12.6% and 0.8%, respectively. Therefore, the incorporation of MBS can enhance the triaxial compressive strength and improve the immobilization capacity of U and Rn of the UMTs bodies solidified during MICP, due to the reduction of pore volume and surface area, the formation of more crystals general gypsum and gismondine, as well as the enhancing of coprecipitation and encapsulation capacity.

• Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.202-213
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• 2022

Antibiotic resistant Escherichia coli cases are increasing high especially in Southeast Asia. Illegal use of the antibiotic in the aquaculture farming may become the culprit of the outbreak and spread into environmental source. A study was conducted to: 1) detect the chloramphenicol (CAL)-resistant gene in E. coli isolated from three aquaculture farms and six rivers of northwestern Borneo and 2) investigate the correlation between cat gene with five common antibiotics used. Isolation of E. coli was done on Eosin methylene blue agar and characterized using indole, methyl red, Voges-Proskauer, citrate tests. E. coli isolates were subsequently tested for their susceptibility to five antibiotics commonly used in aqua-farming. The CAL-resistant E. coli were further analyzed for the presence of resistant genes (cat I, cat II, cat III, cat IV) using multiplex polymerase chain reaction. 42 bacterial colonies were isolated from a total of 80 individual water samples, 34 of which were identified as E. coli. Result showed 85.3% of the E. coli isolates were resistant to amoxicillin, 35.3% were resistant to tetracycline, 29.4% were resistant to CAL, 17.6% were resistant to nitrofurantoin and 8.8% were resistant to nalidixic acid. All of the 10 CAL resistant E. coli isolateswere detected with cat II genes; five isolates detected with cat IV genes; three isolates detected with cat III genes; and another two detected with cat I genes. Pearson correlation coefficient shows highly significant relationship between resistance pattern of CAL with amoxicillin; and CAL with tetracycline. Our findings provide the supplementary information of the CAL resistance gene distribution, thereby improving our understanding of the potential risk of antibiotic resistance underlying within this microbial ecosystem.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.282-297
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• 2022

Purpose: To explore differences in the subgingival microbiome according to the presence of periodontitis and/or type 2 diabetes mellitus (T2D), a metagenomic sequencing analysis of the subgingival microbiome was performed. Methods: Twelve participants were divided into 4 groups based on their health conditions (periodontitis, T2D, T2D complicated with periodontitis, and generally healthy). Subgingival plaque was collected for metagenomic sequencing, and gingival crevicular fluids were collected to analyze the concentrations of short-chain fatty acids. Results: The shifts in the subgingival flora from the healthy to periodontitis states were less prominent in T2D subjects than in subjects without T2D. The pentose and glucuronate interconversion, fructose and mannose metabolism, and galactose metabolism pathways were enriched in the periodontitis state, while the phosphotransferase system, lipopolysaccharide (LPS) and peptidoglycan biosynthesis, bacterial secretion system, sulfur metabolism, and glycolysis pathways were enriched in the T2D state. Multiple genes whose expression was upregulated from the red and orange complex bacterial genomes were associated with bacterial biofilm formation and pathogenicity. The concentrations of propionic acid and butyric acid were significantly higher in subjects with periodontitis, with or without T2D, than in healthy subjects. Conclusions: T2D patients are more susceptible to the presence of periodontal pathogens and have a higher risk of developing periodontitis. The pentose and glucuronate interconversion, fructose and mannose metabolism, galactose metabolism, and glycolysis pathways may represent the potential microbial functional association between periodontitis and T2D, and butyric acid may play an important role in the interaction between these 2 diseases. The enrichment of the LPS and peptidoglycan biosynthesis, bacterial secretion system, and sulfur metabolism pathways may cause T2D patients to be more susceptible to periodontitis.

• Biomedical Science Letters
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• v.28 no.3
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• pp.195-199
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• 2022

The use of copper antibacterial films as an effective infection prevention method is increasing owing to its ability to reduce the risk of pathogen transmission. In this study, we evaluated the bacterial contamination of the antibacterial copper membrane attached to a door handle at a university over time. Six mounting locations with high floating population were selected. In three sites, the door handles with the antibacterial film were exposed, while the remaining three were not attached with the antibacterial films. On days 7 and 14, isolated bacterial strains were inoculated in BHI broth and agar, respectively. Colony-forming units (CFU) were determined after incubation. Strain identification was performed using bacterial 16s rRNA PCR and sequencing. Results showed that the bacterial population on day 14 significantly increased from 6 × 10⁹ CFU/mL (day 7) to 2 × 10¹⁰ CFU/mL. Furthermore, strain distribution was not different between the on and off the copper antibacterial film groups. In conclusion, although copper has an antibacterial activity, microbial contamination may occur with prolonged use.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.131-141
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• 2023

Dental caries is a multifactorial disease influenced by interactions between teeth, biofilm, dietary factors, and various biological, behavioral, sociocultural, and genetic factors. Recent research has shown that dental caries results from dysbiosis, an imbalance in the oral microbial community, shifting the concept from an infectious disease to a non-communicable disease (NCD). Dental caries shares similarities with other chronic NCDs such as cardiovascular diseases and diabetes, as they all relate to dietary intake, lifestyle habits, and environmental factors. Considering the high prevalence of dental caries and its impact on people's health and quality of life, it is important to understand dental caries as an NCD and develop effective oral health management strategies. Ecological prevention methods and efficient public health policies should be provided to reduce risk factors associated with dental caries.