• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.389-396
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• 2018

Marine pathogenic bacteria, such as Streptococcus parauberis, Edwardsiella tarda and Vibrio harveyi, can cause lethal infections in farmed fish, ozone and antibiotics, are employed to sterilize waters used for rearing fish to mitigate this threat. The most widely used method is treatment with sodium hypochlorite solution. However, the maintenance of a constant concentration of chlorine in rearing waters can be difficult. We investigated the potential of a mixed oxidant (MO) solution generated by electrolysis of sea water to improve water quality. We measured the survival rates of fish pathogenic bacteria exposed to different concentrations of MO (0.5, 1.0, 1.5 and 2.0 MO) and sodium hypochlorite (0.5, 1.0, 1.5 and 2.0 ppm) for various lengths of time (0, 5, 10, 15, 20, 25 and 30 min). We found a time-dependent decrease in the survival rates of the tested pathogenic microorganisms. The sterilization effect of the MO solution on pathogenic organisms was greater than that of sodium hypochlorite for gram-negative and gram-positive bacteria. We conclude that MO solution produced by electrolysis could be used to maintain a constant chlorine concentration in aquaculture systems.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.321-332
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• 2013

Purpose: This study was examined the characteristics of bacteria isolated from the dental stone that is made ??in the dental laboratory. Methods: 104 dental stones samples were collected from the 4 dental laboratory. Characteristics of bacteria were investigated by microorganism isolation culture method using a Blood Tryptic Soy Agar(TSA) medium. Results: The detected various bacteria was confirmed as pathogenic bacteria, non-pathogenic bacteria and natural bacteria. The isolated bacterial number was confirmed $2.9{\times}10^3CFU$ and maxium bacterial number of $3.0{\times}10^4CFU$. Conclusion: Therefore, infection prevention education is required, it must be to live up the hand-washing and wear protective clothing to protect themselves when working in a dental laboratory.

• The Korea Genome Conference
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• 2006.09a
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• pp.55-55
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• 2006

• Biomedical Science Letters
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• v.29 no.4
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• pp.256-262
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• 2023

The purpose of this study is to investigate microbial contamination in water purifiers from two universities (A and B) in Chungcheong region and to evaluate about the harmfulness of the isolated bacteria to the human. The degree of microbiological contamination of six water purifiers at university A was investigated three times from July 2018 to September 2019, and nine water purifiers at university B were investigated in 2023. The isolated bacteria were biochemically identified using an API kit and Vitek-2 system, and then the bacteria were identified to the species level using MALDI-TOF MS. In addition, the possibility of human infection of the isolated bacteria was evaluated through a literature search. In July 2018 and September 2019, the number of bacteria isolated inside the faucet was below the acceptable standard for hot water, but exceed for cold water in all water purifiers. In January and September 2019, bacteria exceeding the acceptable standards were isolated nine times from the cold water of six water purifies (a total of 12 water purifiers). Bacteria identified by MALDI-TOF MS included anaerobic bacteria (Clostridium novyi, Clostridium themopalmarium etc.), Gram-positive bacilli (Microbacterium testaceum, Arthrobacter woluwensis etc.), and Gramnegative bacilli (Acinetobacter nosocomialis, Comamonas kerstersii etc.), which are difficult identify by biochemical methods. In conclusion, bacteria exceeding the acceptable standard were isolated from the cold water of most of the water purifiers. Most of the isolated bacteria were low-pathogenic bacteria from natural environment, but opportunistic bacteria that can cause infection in humans were also isolated from some water purifiers.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.43-47
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• 2002

Jeotgal, salt- fermented sea food, is a kind of Korean traditional foods. We carried out hazard analysis on Changran (stomach and intestine of Alaska pollack) Jeotgal and squid Jeotgal through the whole processing procedures at H Co. located at Guryongpo from April 2000 to September 2001. During this studying period, we educated employee regularly and analyzed hazards on the whole process and then could conclude that pathogenic bacteria and metal particles were most important hazards in Jeotgal. Metal particles in end-product will be eliminated by laser detector before packaging. But bacteria must thoroughly manage through the whole process. Bacteriological qualities of the end products were much improved after education for the employees and by effort for HACCP (Hazard Analysis and Critical Control Point) program introduction. Pathogenic bacteria such as pathogenic Escherichia coli, Salmonella spp., coagulase positive Staphylococcus aureus and Vibrio parahaemolyticus were not detected from not only raw materials but also end products. The falling bacteria in the places such as thawing area, packaging area, seasoning area, fermenting room, subsidiary materials room and storage room were less than 30 CFU per plate for 30 minutes during working time. But those were increased more than 10 times during the resting time. It means that special measures are needed during the break time such as lunch time or exchanging working teams.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.113-119
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• 2003

Soybean sprout pathogenic bacteria were isolated from the large, deep containers of a commercial factory. Over a period of one year, 40 pathogenic-like bacteria were isolated among a total of 732 isolates. In addition to bacteria previously reported to be associated with rotting, such as Pseudomonas putida and Erwinia carotovora, several other genera were also identified: Acinetobacter spp., Chryseobacterium spp., Klebsiella sp., Pantoea agglomerans, Bacillus sp. Fatty acid methyl ester (FAME) analysis using the Microbial ID (MIDI) system, and 16s rRNA sequence analysis, yielded identical results, confirming the identities of these microorganisms. Several types of selective media were not good for identification and determination of population structure in commercial environments, as colony type was not specific to the genus. There was no dominant bacterium, and we were not able to find the main bacterium responsible for soybean spout rot. Even though we did not identify a major target for controlling rot or screening for resistant cultivars, the results of this study indicated that bacterial rot of soybean sprout is endemic. In addition, it emerged that factory epidemics in summer are not caused by the bacteria isolated in this study.

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.130-133
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• 2005

The growth inhibitiory effect of chaff vinegar against various food-borne pathogenic bacteria was evaluated. Bacterial growth was evaluated in chaff vinegar at concentrations of 15, 30, 50, 65, 80, and $100\%$ using the paper disc diffusion method and 0.5, 1.0, 1.5, 1.8, 2.0, 2.2 and $2.5\%$ in broth. In the paper disc diffusion assay, chaff vinegar showed a clear zone on both the Gram-positive bacteria; Listeria monocytogenes, Staphylococcus aureus and Gram-negative bacteria; Escherichia coli O157:H7, Salmonella Typhimurium, and Vibrio parahaemolyticus. Chaff vinegar exhibited the greatest growth inhibition for V. parahaemolyticus. The bactericidal effect of chaff vinegar on the E. coli O157:H7 was tested at concentrations ranging from 0.5 to $2.5\%$ (v/v) in the LB broth media. Chaff vinegar retarded the lag phase time of the growth curve in proportion in a concentration-dependent manner. Chaff vinegar at $2.5\%$ completely inhibited the growth of E. coli O157:H7.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.180-184
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• 2019

Aerobic bacteria, coliforms, Escherichia coli, and pathogenic bacteria were investigated in laver Porphyra sp. samples from various regions of Korea. The mean bacterial counts were $6.9{\pm}0.87log\;CFU/g$ (range 4.0 to 7.7) log CFU/g in dried laver, $2.83{\pm}4.36log\;CFU/g$ in roasted laver, and $4.93{\pm}1.43log\;CFU/g$ in seasoned laver. Coliforms were most abundant (mean count: $2.1{\pm}1.01log\;CFU/g$) in dried laver. No pathogenic bacteria, including Staphylococcus aureus, Salmonella spp. Vibrio parahaemolyticus, or Listeria monocytogenes, were detected in any of the samples. Aerobic microorganisms were the most diverse microorganisms in dried laver. Staphylococcus spp. were predominant, but S. aureus was not detected. Standardization of laver production is necessary to ensure a hygienic product because laver products are often ingested without heating or cooking, and the production process is simple.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.330-337
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• 1997

The sensitivity of various pathogenic bacteria (Aeromonas hydrophila, Estherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus 196E, Salmonella typhimurium and Vibrio parahaemolyticus) to the spices, allspice, clove, oregano, and thyme, was tested. Tryptic soy broth (TSB) containing 0∼2% (w/v) of spices was inoculated with 10sup 5/∼10$\^$6/ cells/$m\ell$ of each bacterium and incubated at 35$^{\circ}C$ for 24 hr. The growth of pathogenic bacteria was inhibited with increasing concentrations of spices in the culture broth. At 2％ spice concentration, Gram positive bacteria were more sensitive than Gram negative bacteria with the exception of V. parahaemolyticus. Clove had the highest antibacterial activity, followed by allspice and oregano. At the concentration of 0.3%, clove inhibited the growth of all strains tested. Kanagawa-positive strain of V. parahaemolyticus displayed the highest sensitivity to clove and allspice. Thyme was the least effective for growth inhibition, while 1％ clove killed all pathogens tested.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.459-464
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• 2019

This study aimed to identify and characterize the antimicrobial activity of prodigiosin produced by Serratia sp. $PDGS^{120915}$ isolated from stream water in Busan, Korea; the identification was performed using phonological, biochemical, and molecular techniques, including 16S rRNA sequence analysis. Prodigiosin from the bacterial culture was purified by high-performance liquid chromatography (HPLC), and its antimicrobial activity and minimum inhibitory concentrations (MICs) were evaluated against 10 intestinal pathogenic gram-positive and negative bacteria. The results revealed that the isolated prodigiosin exhibited high antimicrobial activity against Listeria monocytogenes, Bacillus cereus, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, and Vibrio parahaemolyticus; further, the isolated prodigiosin showed minimum inhibitory concentrations (MICs) between $3{\mu}g/ml$ and 30 mg/ml, but they were not active against Bacillus subtilis, Enterococcus faecalis, Klebsiella pneumonia, and Escherichia coli. In conclusion, prodigiosin isolated from Serratia sp. $PDGS^{120915}$ showed high antimicrobial activity against intestinal pathogenic bacteria and has potential applications in the development of new antimicrobial agents.