• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.99-106
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• 2016

This study was aimed to assess microbiological contamination level of Liriope platyphylla farms (A, B, and C) located in Cheongyang, Chungnam province. Specimens sampled from those farms and L. platyphylla tuberous roots were assessed for sanitary indication bacteria such as total aerobic bacteria, coliforms, and Escherichia coli and pathogenic bacteria such as Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus and Bacillus cereus, quantitatively and qualitatively. As a result, those farms are not contaminated by E. coli O157:H7, L. monocytogenes, Salmonella spp., at all. And S. aureus was only found qualitatively from workers' gloves at a farm. As a whole, those farms (soil, harvest container, harvester, cleanser, washing water and tray) were maintained in a low level of microbiological contamination. However a cleanser was contaminated by coliforms ($4.35log\;CFU/100cm^2$), and it is required to improve farm hygiene. Microbiological contamination level of L. platyphylla tuberous root was decreased in the postharvest process including washing and drying.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.168-173
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• 2004

Radio-sensitivity of pathogens in commercial marinated beef ribs, Galbi, and effect of irradiation on microbiological safety and sensory properties of marinated beef rib were investigated. Commercial raw marinated beef ribs were highly contaminated by pathogenic microorganisms including Bacillus cereus, Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus, ranged from $10^{3}\;to\;10^{4}\;CFU/g$. Gamma irradiation reduced pathogen count during storage. No viable cells of pathogens were observed in sample irradiated at 7.5 kGy except for Bacillus cereus. Radio-sensitivity of inoculated pathogens in marinated beef ribs and commercial one showed $D_{10}$ value of 0.54-0.60 and 2.15-2.98, respectively, In sensory evaluation irradiated sample showed highest color and overall acceptance among treatments (p<0.05). Results indicate low dose (2.5-5.0 kGy) irradiation is effective for ensuring safety of marinated beef ribs without decreasing sensory quality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.237-243
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• 2020

Listeria sp. is one of the pathogenic bacteria causes the infection listeriosis, through mainly raw food such as fishery food, dairy food and vegetables. Listeria sp. is a Gram-positive, non-spore-forming, motile, and facultative anaerobic bacterium. Because of the tolerance of Listeria sp. to low temperature and high salt concentration, it is very difficult to prevent them contaminated in the food, which do not require heating, especially, such as raw fishery products. So prevention and removal of bacterial contamination at the food manufacturing stage is the best method. In this study, therefore, several natural products including Psidium guajava and Geranium thunbergii were screened to investigate the antibacterial activity against Listeria sp., with expectation of fewer side effects and fewer resistance problems. Significant effects of two extracts were confirmed by well diffusion assay, MIC assay, and growth inhibition assay. P. guajava and G. thunbergii showed MIC values at 64-256 ㎍/mL meaning strong antibacterial activities against 6 kind of Listeria sp. tested. And the growth of Listeria sp. in the liquid media was actually inhibited by the addition of these two extracts.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.271-277
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• 2010

The purpose of this study is to investigate the seasonal variation of picoplankton community in Lake Juam depending on the change of physico-chemical factors such as rainfall, water depth, DO and pH. The concentration of chlorophyll-a was most high as 18.03 mg/$m^3$ in July when the rainfall and water temperature were highest. The concentration was gradually decreased in October, April and that of January was decreased most low as 1.86 mg/$m^3$. The highest concentration of the Chl-a was shown at 2 and 5 m of water depth than surface, and the concentration was gradually decreased when the water depth becomes deep. Overall, microplankton was the highest rate as 33.9~54.2%, nanoplankton was 24.3~30.5% and picoplankton was 21.6~41.2%. Picoplankton was included as considerable concentration in the water of Juam lake. Therefore it is necessary to remove thoroughly the picoplankton in the water treatment processes such coagulation·sedimentation and sand filtration. The protoplasm released from destruction of picoplankton by chlorine has high possibility to cause regrowth of bacteria and pathogenic microorganism in the distribution system by playing the role of the assimilable organic carbon.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.85-93
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• 2017

The urinary tract infection (UTI) is one of the most important infections in hospital. The overuse and misuse of antimicrobial agents and the resulting emergence of resistant microorganisms have made choices regarding antimicrobial therapy more difficult. This study examined the changes in the antibiotic susceptibility to the causative organisms of urinary tract infections to provide useful information on the choice of adequate drugs in the treatment of urinary tract infections. The medical records of 2,707 patients with more than $10^5/ml$ microorganism in urine culture between January 2010 and December 2015 were reviewed retrospectively. The most common pathogenic organism was E. coli (28.1%). In the case of E.coli, there were no differences in frequency from 2010 to 2015 in men, but since 2014, the frequency decreased gradually since 2014 in women. For E. coli, the resistance rates to antibiotics were 72.2% in ampicillin, 44.9% in trimethoprim/sulfamethoxazole (TMP/SMX), and 41.3% in ciprofloxacin, but the 2nd, 3rd, and 4th cephalosporin (5%) had low antibiotic resistance rates. The pathogens of urinary tract infection are becoming diverse and their frequencies are also changing over time. These results suggest that the recommended drugs for UTI should be selected more carefully for in-patients and out-patients.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.303-311
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• 1996

The microflora changes of 10 water-controled treatments combined with livestock manures(pig, chicken) and bulking agents(sawdust, paper sludge) were investigated. The B/F values of the P-1 and C-1(65%, $H_2O$) treatments were 3571 and 5400 respectively, but those of the P-4 and C-4(50%, $H_2O$) treatments showed very low values, 667 and 334, respectively. The B/F values tended to increase with higher water content of the treatments. In the composting processes, the successions of microflora, adapting the compost environments, took place via fluctuating temperature. In the high temperature period, the numbers of mesophilic bacteria and fungi decreased, but that of the spore forming bacteria increased. However, the number of mesophilic bacteria inereased during the cold period. The B/F values of compost ranged 25-300, which indicates a decrease in the quantity of bacteria. The time required for the temperature of compost to reach $60^{\circ}C$ showed different patterns. There was no pathogenic microorganism in the treatments which reached a high temperature in a short period of time, but, in the treatments which reached a high temperature over a Long period of time, the pathgenic microorganism was not still alive.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.721-726
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• 2012

Lactic acid bacteria (LAB) are able to secrete antimicrobial peptides called bacteriocins, which inhibit other bacteria such as pathogenic microorganisms. Therefore, bacteriocin-producing starters can be used as natural biopreservatives for various foods. The objective of this study was to screen and characterize bacteriocin-producing LAB from Kimchi and to investigate their applicability as a starter in Kimchi fermentation. To screen bacteriocin-producing LAB, gram-positive and gram-negative bacteria were used as indicators. To measure the antimicrobial activities of isolates, agar well diffusion assay method was used. According to the results, bacteriocin produced by $Lb.$ $sakei$ B16 showed antimicrobial activity against $Listeria$ $monocytogenes$ ATCC 19115, $Escherichia$ $coli$ KCTC 1467, and$Lactobacillus$ $plantarum$ KTCT 3104. Furthermore, bacteriocin was very stable after treatment with high temperature and high and low pH, but its effects were inhibited by treatment with proteolytic enzymes such as trypsin, proteinase K, and ${\alpha}$-chymotrypsin, revealing their bacteriocin-like protein- based structure. These results suggest that $Lb.$ $sakei$ B16 and its bacteriocin are good candidates as a functional probiotic and natural biopreservative, respectively, in fermented foods.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.18 no.3
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• pp.187-192
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• 2015

Purpose: Measurement of serum ceruloplasmin level is the first step in screening for Wilson's disease (WD). Despite the rarity of WD in the general population, ceruloplasmin levels are routinely measured through hepatitis screening in both adults and children. Herein, we evaluated the diagnostic value of ceruloplasmin for the diagnosis of WD among children with hepatitis. Methods: We retrospectively reviewed data on serum ceruloplasmin levels measured as a serologic marker for patients with hepatitis at Asan Medical Center (Seoul, Korea) between from January 2004 to November 2013. The diagnosis of WD was confirmed by the identification of pathogenic variants in the ATP7B gene. To determine the diagnostic accuracy of ceruloplasmin, receiver operation characteristic (ROC) curves were constructed and the area under curve (AUC) were calculated. Results: Measurements of serum ceruloplasmin were performed in 2,834 children who had hepatitis. Among these, 181 (6.4%) children were diagnosed with WD. The sensitivity, specificity, and accuracy of a ceruloplasmin level of <20 mg/dL in the discrimination of WD were 93.4%, 84.2%, and 84.8%, respectively. In this study, 418 (14.7%) false-positive cases and 12 (0.4%) false-negative cases were noted. Using a ROC curve, a ceruloplasmin level of ${\leq}16.6mg/dL$ showed the highest AUC value (0.956) with a sensitivity of 91.2%, a specificity of 94.9%, and an accuracy of 94.7%. Conclusion: The measurement of serum ceruloplasmin was frequently used for the screening of WD in children, despite a low positive rate. The diagnostic value of ceruloplasmin may be strengthened by adopting a new lower cut-off level.

• Korean Journal Plant Pathology
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• v.3 no.4
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• pp.252-260
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• 1987

Incidence of lettuce drop was observed throughout the growing season in the vinylhouse at the southern part of Korea, Kimhai. Occurrence of this disease was especially severe at the seedling stage. Number of sclerotia in surface soil $(30\times30\times5cm)$ was 22.0 at the seedling stage, and 5.3 at harvest in the infected area. Temperature for mycelial growth ranged from 5 to $30^{\circ}C$ with optimum temperature at $25^{\circ}C$. Sclerotia were formed fewer at low temperature, but their size was larger resulting in heavier dry weight than that at high temperature. The apothecia were formed from the sclerotia that were buried in March, April and September upto 3cm soil depth, but formed from those buried only 1 em soil depth in October. Sclerotia buried in June and December did not form apothecia regardless of soil depth by 90 days. The sclerotia buried in the 5cm of soil depth did not form apothecia. Sclerotia that were embedded in wet or flooded soil at $25^{\circ}C$ and $30^{\circ}C$ for 5 weeks lost their viability. Infection of lettuce was possible with mycelia originated from sclerotia on autoclaved lettuce plant fragments. The fungus was pathogenic on 25 plant species in 8 families in artificial inoculation tests. Lettuce seedlings appeared to be infected by airborne ascospore originated from sclerotia on crops and weeds around paddy fields, because sclerotia existing in soil might perish under long flood conditions during rice cultivation.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.91-99
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• 2011

Risk ranking must be determined for various hazards/food combinations to conduct microbial risk management effectively. Risk Ranger is a simple, easy-to-use calculation tool developed in Microsoft Excel and designed to rank the risk (low, medium, and high) for semi-quantitative microbial risk assessment. The user is required to answer 11 questions in Risk Ranger related to 1) severity of the hazard, 2) likelihood of a disease-causing dose of the hazard being present in the meal, and 3) the probability of exposure to the hazard in a defined time. This study determined the risk ranking for twenty three combinations of foodborne pathogens/potentially hazardous foods (PHFs) using a Risk Ranger. In this study, pathogenic E. coli in fresh cut produce salad was scored as 79, which was the highest rank among the 23 combinations of the foodborne pathogens and PHFs. On the other hand, zero risk was obtained with V parahaemolyticus in sushi, Salmonella in meat products and E. coli O157:H7 in hamburger patties. Although Risk Ranger is very simple method to rate the risk of foodborne pathogens and PHFs combination, the accuracy of result was mainly affected by the availability and accuracy of data in the literature. According to the result of literature review, the data are needed for contamination rate of raw materials, consumption amount/frequency of PHFs, and the effect of processing on pathogen. Risk ranking must be continuously revalidated with new data.