• 한국토양비료학회지
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• 제47권6호
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• pp.432-436
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• 2014

While searching for healthier diets, people became more attentive to agricultural organic products. However, organic foods may be more susceptible to microbiological contamination because of the use of livestock manure compost and liquid manure, potential sources of pathogenic bacteria. This study was undertaken to investigate the persistence of Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes in soil, liquid manure amended soil, and liquid manure. Loamy soil, liquid manure amended soil, and liquid manure were inoculated with S. enterica, E. coli O157:H7, and L. monocytogenes. Samples were incubated in consistent moisture content at $25^{\circ}C$. Samples had been periodically collected during 120 days depending on the given conditions. S. enterica and E. coli O157:H7 survived over 120 days in loamy soil and over 60 days in liquid manure amended soil, respectively. L. monocytogenes decreased faster than other pathogens in soil. S. enterica, E. coli O157:H7, and L. monocytogenes survived for up to 5 days in liquid manure. S. enterica and E. coli O157:H7 in soil decreased by 2 to $2.5log\;CFU\;g^{-1}$ for 120 days. S. enterica and E. coli O157:H7 in liquid manure amended soil decreased slowly for 21 days. However, S. enterica, E. coli O157:H7, and L. monocytogenes sharply decreased after 21 days. S. enterica, E. coli O157:H7, and L. monocytogenes in soil increased by 0.5 to $1.0log\;CFU\;g^{-1}$ for 7 days. Foodborne pathogens in soil and liquid manure amended soil gradually decreased over time.

• Journal of Microbiology
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• 제38권4호
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• pp.270-274
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• 2000

Pathogenic Salmonella typhimurium can invade the intestinal epithelium and cause a wide range of diseases including gastroenteritis and bacteremia in human and animals. To identify the genes involved in the infection, the invasion determinant was obtained from S. typhimurium 82/6915 and was subcloned into pGEM-7Z. A subclone DHl (pSV6235) invaded HEp-2 and Chinese hamster ovary epithelial cells and contained a 4.4 kb fragment of S. typhimurium genomic region. Compared with the host strain E. coli DHl, the subclone DHl (pSV6235) invaded cultured HEp-2 and Chinese hamster ovary cells at least 75- and 68-fold higher, respectively. The invasion rate of E. coli DHl for the cells significantly increased by harbouring the genomic region derived from pathogenic S. typhimurium 82/6915.

• 한국식품과학회지
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• 제36권3호
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• pp.507-513
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• 2004

시판 새우젓의 미생물학적 특성을 평가한 결과 총균수는 기업 새우젓과 재래 새우젓이 각각 $10^{2}-10^{4}\;CFU/g,\;10^{1}-10^{6}\;CFU/g$으로 나타났다. 시판새우젓에서 대장균군은 검출되지 않은 제품, $10^{1}-10^{2}\;CFU/g,\;10^{3}-10^{4}\;CFU/g$ 수준의 제품이 재래 새우젓은 전체 25제품 중 각각 1개, 8개, 8개였으며, 기업 새우젓은 전체 8제품 중 각각 3개, 4개, 1개 제품이었다. 비브리오균은 전체 25개 제품 중 10개 제품에서는 검출되지 않았고, 나머지 제품에서는 $10^{1}-10^{3}\;CFU/g$ 수준으로 검출되었다. 이들 검출된 미생물을 생화학적 특성과 API system을 통해 동정한 결과 병원성 미생물은 분리되지 않았다. 또한, 시판 새우젓과 염농도를 9. 18, 27%로 달리하여 제조한 새우젓에 Salmonella sp., Escherichia coli O26, Staphylococcus aureus를 접종하여 생육을 평가한 결과 숙성이 완료되어 시판되는 새우젓에 접종하였을 경우에는 15일 이내에 모두 사멸하였으며, 제조 직후 숙성되기 전에 접종하였을 경우에는 숙성기간인 90일 이내에 모두 사멸하였다.

• 대한영양사협회학술지
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• 제24권4호
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• pp.330-343
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• 2018

Recently, there has been a growing demand for natural preservatives because of increased consumer interest in health. In this study, we produced Lactobacillus rhamnosus cell-free supernatant (LCFS) and evaluated and compared its antimicrobial activity with existing natural preservatives against pathogenic microorganisms and in chicken breast meat contaminated with Escherichia coli and Staphylococcus aureus. Lactobacillus rhamnosus cell-free supernatant possessed 30 units of lysozyme activity and contained 18,835 mg/L of lactic acid, 2,051 mg/L of citric acid and 5,060 mg/L of acetic acid. Additionally, LCFS inhibited the growth of fourteen pathogenic bacteria, S. aureus, Bacillus cereus, Listeria monocytogenes, Vibrio parahaemolyticus, Listeria innocua, S. epidermidis, L. ivanovii, E. coli, Pseudomonas aeruginosa, Shigella sonnei, Shi. flexneri, Proteus vulgaris, Pseudomonas fluorescens, and Klebsiella pneumoniae. The antibacterial activity of LCFS was stronger than that of egg white lysozyme (EWL), Durafresh (DF) and grapefruit seed extract (GSE). Additionally, LCFS maintained its antimicrobial activity after heat treatment at $50^{\circ}C{\sim}95^{\circ}C$ and at pH values of 3~9. Moreover, LCFS inhibited the growth of E. coli and S. aureus in chicken breast meat. In conclusion, it is expected that LCFS, which contains both lysozyme and three organic acids, will be useful as a good natural preservative in the food industry.

• 한국미생물·생명공학회지
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• 제47권3호
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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.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.492-499
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• 2017

Combined treatment with gaseous and aqueous chlorine dioxide ($ClO_2$) was performed to improve the microbiological safety and quality of paprika. A single treatment of 50 ppmv $ClO_2$ gas for 30 min decreased the populations of Escherichia coli O157:H7 and Salmonella Typhimurium by 2.33 and 2.91 log CFU/g, respectively. In addition, a single treatment of aqueous $ClO_2$ (50 ppm) for 5 min decreased these populations by 1.86 and 1.37, respectively. The most dramatic effects were achieved by combined treatment of 50 ppm aqueous and gaseous $ClO_2$ for 30 min, which decreased populations of E. coli O157:H7 and S. Typhimurium by 4.11 and 3.61 log CFU/g, respectively. With regard to the qualities of paprika, no adverse effects were elicited by the combined treatment. Thus, combined treatment with aqueous and gaseous $ClO_2$ is a suitable approach that can be used to improve the microbial safety and quality of paprika.

• 대한한의학방제학회지
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• 제27권4호
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• pp.257-267
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• 2019

Objectives: The purpose of this study was to establish experimental evidence for the antimicrobial effects of 51 herbal formulae commonly used in traditional Korean medical institutions. Methods: The antimicrobial activities of herbal formulae were screened using the disc diffusion method against 10 pathogenic microorganisms (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Vibrio parahaemolyticus, Escherichia coli DH5α, E. coli O157, Salmonella enteritidis, Yersinia enterocolitica, Shigella flexneri, and Helicobacter pylori). Of the 51 herbal formulae, 13 herbal formulae with antimicrobial activity were selected and their dose-dependency were confirmed. Results: Nine herbal formulae, including Gyeji-tang, Dangguisu-san, Saengmaek-san, Samul-tang, Ssanghwa-tang, Socheongryong-tang, Yukmijihwang-tang, Jakyakgamcho-tang, and Paljung-san, presented antibacterial activity against B. cereus. The effects of Saengmaek-san and Paljung-san was sustained for 48 hr. On L. monocytogenes, Dangguisu-san and Hyangsapyeongwi-san showed antimicrobial activity, but only Hyangsapyeongwi-san maintained the activity for 48 hr. Thirteen herbal formulae such as Galgeun-tang, Gyeji-tang, Dangguisu-san, Mahwang-tang, Banhasasim-tang, Saengmaek-san, Socheongryong-tang, Yukmijihwang-tang, Jakyakgamcho-tang, Cheonwangbosim-dan, Palmijihwang-tang, Paljung-san, and Hwanglyeonhaedok-tang showed antimicrobial activity against V. parahaemolyticus, and the activity was maintained for 48 hr. The 51 herbal formulae did not show any antimicrobial activity against seven strains such as E. coli DH5α, E. coli O157, S. aureus, S. enteritidis, Y. enterocolitica, S. flexneri, and H. pylori. Conclusions: Nine, two, and thirteen herbal formulae showed antimicrobial activities against B. cereus, L. monocytogenes, and V. parahaemolyticus in a dose-dependent manner, respectively. The results of antimicrobial activity of 51 herbal formulae against 10 microorganisms might be used as the basis for new application of herbal formulae.

• 한국수산과학회지
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• 제55권4호
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• pp.431-436
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• 2022

For the safety assessment of microbiological and chemical hazards in katsuobushi, fifteen samples of katsuobushi were purchased from supermarkets. The contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine pathogenic bacteria [Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Bacillus cereus, Vibrio parahaemolyticus, Clostridium perfringens, Enterohemorrhagic E. coli (EHEC), Yersinia enterocolitica and Campylobacter jejuni/coli] were quantitatively or qualitatively assessed. Additionally, the heavy metals (total and methyl mercury) content, radioactivity (¹³¹ I, ¹³⁴ Cs⁺ and ¹³⁷ Cs) were quantitatively assessed. Microbial and chemical analyses were performed using standard methods in Korean food code. The contamination level of total viable bacteria was 2.70 (1.18-4.42) log CFU/g. Coliforms, E. coli and S. aureus were not detected in any samples. Other eight pathogenic bacteria were negative in all samples. The contamination levels of total and methyl mercury were 0.366 (0.227-0.481) and 0.120 (0.002-0.241) mg/kg, respectively. In addition, radioactivity was not detected in any samples. The results will be helpful in revitalizing domestic use and boosting exports of katsuobushi because the microbiological and chemical safety of katsuobushi has been assured. Furthermore, the results may be used as a basis for performing chemical and microbial risk assessments of katsuobushi.

• Journal of Dairy Science and Biotechnology
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• 제41권3호
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• pp.126-137
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• 2023

본 연구는 쪽파(A. wakegi)로부터 유산균을 분리하였고, 이 균으로부터 얻어진 배양 상징액이 병원성균에 대하여 항균활성을 나타내는지 조사하였다. 먼저 분리된 유산균으로부터 얻어진 배양 상징액에 대해서 병원성균인 E. coli KCCM 11587, E. coli KCCM 11591, E. coli KCCM 11596, E. coli KCCM 11600, S. Enteritidis NCCP 16947, S. Thompson NCCP 11704, 그리고 S. Typhimurium NCCP 16960의 항균활성을 측정하였다. 그 결과 얻어진 유산균 배양액은 병원성균에 대하여 현저한 항균활성을 보여주었다. 항균활성은 배양 상징액 첨가량이 증가함에 따라 현저한 효과를 나타내었다. 또한 병원성균에 대한 항균활성에 대하여 얻어진 배양 상징액의 pH 변화와 열의 변성에 의하여 같은 항균효과를 나타내는지를 조사하였다. 즉, 배양 상징액을 pH 7로 조정하여 병원성균에 대한 항균활성을 측정한 결과, 억제효과는 나타나지 않았다. 따라서 얻어진 배양 상징액의 병원성균에 대한 항균활성은 유기산에 의하여 영향을 받은 것으로 판단된다. 한편, 배양 상징액의 열에 대한 안정성을 측정한 결과는 열처리를 하지 않은 대조구와 같은 항균활성을 나타내었다. 따라서 얻어진 유산균 배양액은 열에 대하여 안정한 것으로 나타내었다.

• 한국환경보건학회지
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• 제32권4호
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• pp.316-323
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• 2006

This study was performed to assess the microbial contamination level for the processing of sandwich products in the middle of Gyeongnam province from December 2004 to January 2005. A total of 85 samples were collected from 5 sandwich shops. These samples were tested sanitary indication bacteria, such as aerobic Plate count(APC), coliforms, and Escherchia coli and pathogenic bacteria such as Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus. As a result of APC and coliform count ranged 0-4.59 $log_{10}$ CFU/(ml, g, 100 $cm^2$, hand) and 0-3.86 $log_{10}$ CFU/(ml, g, 100 $cm^2$, hand), respectively. Especially, the highly contaminated items for APC were confirmed 1.64-4.59 $log_{10}$ CFU/g to employees', raw materials and sandwich in all items. Escherichia coli was isolated from 5 samples. Listeria monocytogenes and Staphylococcus aureus were detected in 1 sample and 11 samples from utensil, raw materials and sandwiches, respectively. However, Escherichia coli O157:H7 and Salmonella spp. were not detected in anywhere. For the production of safety sandwich, education of sanitation for employees, control of raw materials, and continuous monitoring for microorganism will be required.