• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.19-30
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• 2022

In this study, a simple loop-mediated isothermal amplification (LAMP) combined with visual detection method (vLAMP) assay was developed for the rapid and specific detection of African swine fever virus (ASFV), overcoming the shortcomings of previously described LAMP assays that require additional detection steps or pose a cross-contamination risk. The assay results can be directly detected by the naked eye using hydroxynaphthol blue after incubation for 40 min at 62℃. The assay specifically amplified ASFV DNA and no other viral nucleic acids. The limit of detection of the assay was <50 DNA copies/reaction, which was ten times more sensitive than conventional polymerase chain reaction (cPCR) and comparable to real-time PCR (qPCR). For clinical evaluation, the ASFV detection rate of vLAMP was higher than cPCR and comparable to OIE-recommended qPCR, showing 100% concordance, with a κ value (95% confidence interval) of 1 (1.00~1.00). Considering the advantages of high sensitivity and specificity, no possibility for cross-contamination, and being able to be used as low-cost equipment, the developed vLAMP assay will be a valuable tool for detecting ASFV from clinical samples, even in resource-limited laboratories.

• The Journal of Korean Society for School & Community Health Education
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• v.8 no.2
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• pp.79-95
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• 2007

A study was conducted in order to develope HACCP model in school lunch in Korea. Results: 1. Of 22 menus 4(18%) were non heating processes (#1), 2(9%) were food handling by using hands (#2), and 16(73%) were heating processes (#3). Of 279 menus 36(12.9%) belong to process #1, 8(2.9%) to process #2, and 235(84%) to process #3. 2. The critical control points for process #1 were contamination by hands of food handlers, and unsanitary food preparation habits of food handlers. Those for process #2 were improper heating temperature, contaminations by food handlers' hands, and unsanitary food handling habits, and cross contamination by unclean utensils and equipment. 3. Management criteria for the CCPs were conditions of food storage, refrigeration, freezing, food cooking temperature, personal hygiene, washing and sanitization of utensils and equipment. 4. Monitoring criteria for CCPs were observation, temperature checking, inspection of utensils and equipment, and practice of good personal hygiene. 5. Corrective actions were refusal of unsafe products, correction of improper temperature, proper cleaning and sanitization, and proper reheating time and temperature.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1551-1556
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• 2016

Broiler meat production worldwide has been plagued by lethal food-poisoning bacteria diseases, including listeriosis. A fatality rate of 15.6% was recorded in human beings in the EU in 2015. During 2013, a total of 200 poultry farm samples, including litter, chicken breast, farm feed, and drinking water, were collected to generate baseline data for the characterization of the genus Listeria in broiler poultry farms. Listeria spp. were detected in a total of 95 (47.5%) poultry farm samples. The isolates of Listeria spp. included L. innocua (28.5%), L. ivanovii (12.5%), L. welshimeri (4.5%), and L. monocytogenes and L. seeligeri (1% each). Listeria spp. contamination rates were higher in farm feed (70%), followed by litter (52.5%), chicken breasts (42.2%), and drinking water (10%). Almost all Listeria spp. isolates were resistant to more than three classes of antibiotics (multidrug resistant). Besides this, we observed a significant resistance level to penicillin and fluoroquinolone drugs. However, lower resistance levels were recorded for broad-spectrum cephalosporins. The inlA, inlC, and inlJ virulence genes were detected in almost all of the L. monocytogenes isolates. Thus, food safety management approaches and interventions at all stages of the broiler rearing cycle were needed to control cross-contamination and the zoonotic potential of listeriosis.

• Journal of Microbiology
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• v.38 no.2
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• pp.99-104
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• 2000

Hydrogen peroxide has been used in cleaning the piping of an advanced high-purity water system that supplies ultra-high purity water (UHPW) for 16 megabyte DRAM semiconductor manufacturing. The level of hydrogen peroxide-resistant bacteria in UHPW water was monitored prior to and after disinfecting the piping with hydrogen peroxide. Most of the bacteria isolated after hydrogen peroxide disinfection were highly resistant to hydrogen peroxide. However, the percentage of resistant bacteria decreased with time. The hydrogen peroxide-resistant bacteria were identified as Micrococcus luteus, Bacillus cereus, Alcaligenes latus, Xanthomonas sp. and Flavobacterium indologenes. The susceptibility of the bacteria to hydrogen peroxide was tested as either planktonic cells or attached cells on glass. Attached bacteria as the biofilm on glass exhibited increased hydrogen peroxide resistnace, with the resistance increasing with respect to the age of the biofilm regrowth on piping after hydrogen peroxide treatment. In order to optimize the cleaning strategy for piping of the high-purity water system, the disinfecting effect of hydrogen preoxide and peracetic acid on the bacteria was evaluated. The combined use of hydrogen peroxide and peracetic acid was very effective in killing attached bacteria as well as planktonic bacteria.

• Journal of radiological science and technology
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• v.44 no.3
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• pp.231-237
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• 2021

The ongoing coronavirus disease 2019 (COVID-19) pandemic has highlighted the importance of hospital hygiene and infection control in hospital settings. To raise hygiene awareness among ultrasound technicians, we evaluated the hygiene status of an ultrasound room, in comparison with that of objects used in daily life. Using the swab method, the following surfaces were examined: eight surfaces in the ultrasound room including the ultrasound probes (convex, linear, sector, 3D), ultrasound track ball, ultrasound keyboard, ultrasound gel (sealed and in use) and pillow as well as four surfaces of everyday objects including subway handles, common computer keyboards, common computer mouse, and cell phones. The streak plate technique was used for inoculation into media, which was observed for the formation of bacterial colonies following incubation for 24 h. Six bacterial strains were detected from objects used in the ultrasound room, including methicillin-resistant Staphylococcus aureus. Four strains of bacteria were detected on surfaces of everyday objects. The equipment and accessories used in an ultrasound room can act as vehicles for infecting patients. Establishment of standardized hygiene protocols and periodic training of the staff are recommended to avoid cross-infection.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.201-209
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• 2016

Many atmospheric pollutants including chemical agents, house dust, and microorganisms cause building-related illnesses through respiration in humans. This study was conducted to analyze the profiles of microbial pollutants in air purifiers used in home, office and playschool. Dominant eleven species of microorganisms were isolated and identified in environmental air and air purifiers. Among them, Staphylococcus sp., Micrococcus sp. and Bacillus sp. are the most dominant species. By phylogenetic analysis of the 16S rRNA gene, the dominant bacteria were identified as Staphylococcus epidermidis, Micrococcus luteus and Bacillus epidermidis, respectively. It has been known that these bacterial species are closely related with food spoilage and human infectious disease. Thus, these results indicate that microbial pathogens related with human illnesses through respiration will be contaminated in air purifiers and also need to develop a method to control those of pathogens for human health.

• Perspectives in Nursing Science
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• v.10 no.1
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• pp.65-76
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• 2013

Purpose: To identify an associations between health care workers' uniforms and health care-associated infection. Methods: Electronic databases, including Ovid-Medline, the Cochrane Library, CINAHL, EMBASE, KMbase, and KoreaMed, were searched. The search terms included doctor, nurse, health care worker/staff/assistant, clothing, (white) gown, uniform, (neck)tie, and attire. Only papers published in English and Korean were included. Results: 16 studies were selected from 1,900 references screened. All of the studies were non-comparative studies except for one. Four were conducted with doctors, six with nurses, one with health care workers including physiotherapists and one for medical staff plus visitors in a neonatal intensive care unit. Doctors more frequently changed their uniforms than neckties; therefore, the degree of contamination was more serious in neckties. The cuff zone was more likely to be heavily contaminated than other areas of long-sleeve gowns. Coats become contaminated quickly once worn, and colony counts reached a similar level within the first few hours after wearing them. Wearing a plastic apron or protective clothing did not prevent the bacterial contamination of nurses' uniforms, and the best way to decrease the contamination was changing to newly laundered uniforms before starting every duty. Conclusion: Healthcare workers' uniforms are a potential source of health care-associated infection although there was no robust evidence. The government must establish standards for laundering of uniforms or a requirement for institutions to provide a laundering service for healthcare workers' uniforms.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.232-236
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• 2005

This study was performed to find out the patterns of Listeria spp. contamination during Kimbab preparation at the specialized restaurants. Samples were collected from ingredients, containers, equipments, and environments from two Kimbab restaurants from July through September, 2004. Isolation rate of Listeria spp. was $43.2\%$ among 264 samples. Strains isolated were Listeria innocua $35.9\%$, L. murrayi $6.8\%$, and L. grayii $0.3\%$. No L. monocytogenes was detected. Contamination level of ingredients, containers, equipments, and Kimbab sampled during afternoon was all significantly higher than the samples collected during morning(P < 0.05). The most influencing factor of contamination was improper handling or no disinfection procedures during Kimbab preparation. Safety controls are recommended as follows; prevention of cross-contamination during ingredients Preparation, temperature control for ingredients and Kimbab during holding, cleaning and disinfection of chopping boards and knives during preparation processing, and frequent changes of disposable gloves. Kimbab restaurants should recognize the importance of safety control using the Good Hygienic Practices.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.186-192
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• 2007

This study was conducted to survey the hygienic status of chicken meats on the microbial levels, which were collected from poultry processing plants located in the local provinces in nationwide including the JeJu island (n=15) in 1997. In particular, Salmonella spp., Campylobacter jejuni, and Listeria monocytogenes, which were retarded as one of the most important entero-pathogens relating to food home illness from poultry, were investigated on their isolation frequency including the other pathogens related on the food-borne illness. A total of 115 processed chickens were submitted on the present study. In general, the bacterial contamination frequency showed more or less lower $(10{\sim}100 cells)$ than those of sold on the retail and super markets and department stores because of lacking of cross-contamination incidences, depending on the total cells, Coliforms and Staphylococcal cells count. While, Salmonella species, Campylobacter jejuni, Listeria monocytogenes, and coagulase positive Staphylococcus aureus isolation frequency of chicken meats from slaughter houses were 58.3%, 37.4%, 43.5%, and 30.4%, in order. But the present microbial isolation data were a little lower levels than those of sold on the retail and super markets and famous department stores in Seoul and GyeongGi province at the same period. It seemed that the cross-contamination problems (including the human, environmental and instrumental factors) during the marketing stage (after the last processing procedure; rinsing step) had the major roles on the increasing of the microbial contamination frequency on the chicken meats after the slaughter houses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1265-1270
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• 2009

Pathogens contaminated on the surface of utensils could contribute to the occurrence of outbreaks due to cross-contamination to foods during the food preparation process. Therefore, the efficacy of chemical sanitizers (chlorine-based and alcohol-based commercial sanitizers) and dry-heat ($71^{\circ}C$) on inhibiting biofilms of five foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Pseudomonas aeruginosa, Listeria monocytogenes, and Staphylococcus aureus) on the surface of stainless steel and polypropylene were investigated in this study. Initial populations of pathogens were 8.8$\sim$9.3 and 9.4$\sim$10.3 log CFU/coupon on the surface of stainless steel and polypropylene coupon, respectively, and these populations were not significantly reduced when they were treated with water for 5 min at room temperature. Treatments with chlorine sanitizer and dry-heat were not effective on inactivating pathogens on the surfaces of stainless steel and polypropylene. In contrast, treatments with alcohol sanitizer were very effective on inactivating pathogens on the surfaced of stainless steel and polypropylene. Reduction levels ranged from 3.4 to 6.4 log and from 5.5 to 7.4 log CFU/coupon in stainless steel and plastic coupons, respectively. From these results, alcohol-based sanitizer could be used as a potential way for controlling microbial contamination on the surface of utensils, cooking equipment, and other related environments.