• Title/Summary/Keyword: pathogenic indicator

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Isolation and Characterization of Watermelon Isolate of Cucumber green mottle mosaic virus(CGMMV-HY1) from Watermelon Plants with Severe Mottle Mosaic Symptoms

  • Shim, Chang-Ki;Han, Ki-Soo;Lee, Jung-Han;Bae, Dong-Won;Kim, Dong-Kil;Kim, Hee-Kyu
    • The Plant Pathology Journal
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    • v.21 no.2
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    • pp.167-171
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    • 2005
  • We isolated the Cucumber green mottle mosaic virus(CGMMV) particles from watermelon leaves and designated as CGMMV-HY1 as a watermelon isolate and attempted to characterize the pathogenic isolate responsible for such an epidemic in watermelon and also to monitor dominant viral isolates in greenhouse. The watermelon plants infected with CGMMV generally showed mottle mosaic, mosaic, growth stunting, necrosis and deformed fruit. The reactions of indicator plants to CGMMV-HY1 were the local lesions on Nicotiana tabacum cv. White Burley, Nicotiana tabacum cv. Samsun, and Chenopodium amaranticola, and the mosaic symptoms only on Cucumis sativus, but the CGMMV-HY1 did not infect Nicotiana sylvesytis, Datura stramonium, Chenopodium quinoa, and Petunia hybrida. Purified virus particles were rod-shaped and about 300 nm long. The coat protein (CP) of purified CGMMV-HY1 was single band with molecular weight of about 16.5 kDa which was confirmed by western blot analysis probed with monoclonal antibody of CGMMV-HY1. The genomic and subgenomic RNAs of 6.4 kb and 0.75 kb were revealed by the electrophoresis on 1.2% formaldehydedenatured agarose gel. Viral and complementary CGMMV-specific primer sets were designed for spanning the genome using previously reported CGMMV sequences. A 464bp of CP gene of CGMMV-HY1 was amplified by RT-PCR and cloned into PGEM-T easy vector. The nucleotide sequence of CP gene of CGMMV-HY1 shared 98%, 99%, and 100% identities with that of CGMMV strains W, KOM, and KW respectively. Based on these results, we identified CGMMV-HY1 as a CGMMV isolate of watermelon, a member of Tobamovirus.

Isolation and Structural Determination of Antifungal Antibiotic from Streptomyces hygroscopicus MJM1004 (Streptomyces hygroscopicus MJM1004가 생산하는 항진균성 항생 물질의 분리 및 구조 결정)

  • Bae, Ju-Yun;Kwon, Hyong-Jin;Suh, Joo-Won
    • Applied Biological Chemistry
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    • v.42 no.4
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    • pp.271-276
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    • 1999
  • Several Streptomyces strains were tested for potent antifungal agents active against phytopathogenic fungi. Among the tested, S. hygroscopicus MJM1004 showed a potent antifungal activity when assayed using Candida albicans as indicator organism. With the strain of MJM1004, fermentation medium for the production of an antifungal agent was developed with varying carbon sources, nitrogen sources, and mineral elements, which resulted in the highest productivity in the medium containing 2% soybean meal, 1% glucose, 2% starch, 0.3% $CaCO_3$, 0.05% $MgSO_4{\cdot}7H_2O$, 0.05% $K_2HPO_4$. The active compound showed a broad spectrum of antifungal activity against several plant pathogenic fungi. The antifungal compound was purified and showed the physicochemical characteristics similar to azalomycin F complex in NMR and MS analysis.

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SURFICIAL DISINFECTION OF ESCHERIACHIA COLI-CONTAMINATED PLAYGROUND SOIL BY UV IRRADIATION

  • Kim, Jae-Eun;Kim, Tong-Soo;Cho, Shin-Hyeong;Cho, Min;Yoon, Je-Yong;Shea, Patrick J.;Oh, Byung-Taek
    • Environmental Engineering Research
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    • v.12 no.2
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    • pp.64-71
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    • 2007
  • The necessity of disinfecting playground soil is an important issue, because pathogenic protozoa, bacteria, and parasite eggs remain viable for several months and can infect children. UV irradiation has been used to decontaminate water but its effectiveness on soil is unclear. We determined the efficacy of UV radiation for inactivation of an indicator bacteria, E. coli (strain ATCC 8739), on playground soil. While 99% inactivation of E. coli in the soil was readily achieved by UV radiation within 55 min at $0.4\;mW\;cm^{-2}$, complete inactivation was not achieved, even after prolonged treatment at $4\;mW\;cm^{-2}$. This was attributed to the irregular surface of the soil. A small number of E. coli escaped the UV radiation because they were situated in indentations or under small particles on the soil surface. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirmed that the surface characteristics of the soil is the major limiting factor in the inactivation of E. coli by UV radiation. Thus UV treatment may not be adequate for disinfecting some soils and should be carefully evaluated before being used on playground soils.

Molecular Approaches to Determine the Character of Serratia marcescens Associated with the Insect Pathogenicity to Brown Planthopper (Serratia marcescens의 곤충 병원성 관련형질 탐색을 위한 분자생물학적 연구)

  • 김희규;배동원;박진희;윤한대
    • Korean journal of applied entomology
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    • v.32 no.3
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    • pp.330-337
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    • 1993
  • A bacterium, pathogenic to Nilaparvata lugens Stal. causing high mortality in 3~5 days, were selected and identified as Serratuz marcescens biotype A2a which is not a nosocomlally infective strain. In order to determine the characters of Serratia marcesce'1lS associated with insect pathogenicity, Tn5 mutagenesis was carried out by conjugating with E. coli pJB4J1. Transconjugants were plate-assayed for missing chitinase, protease and DNase activity. A protease negative mutant was selected for missing JOseet pathogenicity. SEM and TEM revealed the presence of bacterial cells in the epithelial tissue of inner abdomal tissue of the hypodermic layer of abdomen. Such a colonization was limmited to the subjacent tissue inside the intacL cuticular epidermis. These observation supported our result of pathogenicity tests of transconjugants.

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A Study on Oriental Medical Factors of Teenagers' Menstrual Disorders Based on DSOM (한방진단시스템(DSOM)을 이용한 청소년 월경통, 월경량 이상의 한의학적 인자(因子) 연구)

  • Yim, Sun-Hee;Cho, Hye-Sook;Lee, In-Seon;Kim, Kyu-Kon
    • The Journal of Korean Obstetrics and Gynecology
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    • v.23 no.3
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    • pp.156-172
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    • 2010
  • Purpose: In Oriental medicine, menstruation is a significant index of women's health. Especially high school girls often have various menstrual problems. We think that students who have menstrual problem have some symptoms in relation to an etiological cause. So we had carried out this study to investigate association of DSOM scores and an abnormality of menstruation in oriental medicine. Methods: First we have 2137 high school girls answer to menstrual questionnaire that we made and DSOM, next investigated the pathogenic factor of DSOM which effect dysmenorrhea and menorrhagia using regression model. Logistic regression analysis indicate as follows. Results: 1. In comparison with dysmenorrhea, Qi depression(氣滯), blood stasis(血瘀), dampness (濕), phlegm(痰) is associated positively and liver(肝) negatively. The sensitivity is 64.3%, and the specificity is 75.1%. 2. In comparison with menorrhagia, Blood deficiency(血虛), Qi depression(氣滯), blood stasis(血瘀) is associated positively and liver(肝) negatively. The sensitivity is 53.9%, and the specificity is 76.1%. Conclusion: In this study, that has been carried out to organize the diagnosis of dysmenorrhea and menorrhagia in Oriental medicine, we can see that the disease factors of them were correlated with our Medical theory.

Comparative Analysis of Total and Fecal Coliforms in Sea Water (해수의 대장균군과 분변계대장균의 검출률 비교 분석)

  • Kim, Young-Man;Kim, Kyoung-Hee;Park, Hye-Jeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.5
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    • pp.288-292
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    • 2007
  • Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often caused by pathogenic microorganisms originating from fecal contamination, such as Salmonella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefore, data on fecal coliforms are very important for evaluating the safety of fisheries in coastal areas. In this study, 2,226 sea water samples were collected from the southeast coast of Korea, and total and fecal coliforms were compared and analyzed. Total coliforms were detected in 76.5% of the samples and 71.4% of the total coliforms were fecal coliforms. At sea water temperatures above $20.0^{\circ}C$, total coliforms were found in 78.8% of the samples and fecal coliforms constituted 72.0% of the total coliforms. In sea water below $19.9^{\circ}C$, the respective values were 74.6% and 70.9%. These results suggest that temperature does not have a significant effect on the detection of fecal coliforms. When the salinity exceeded 30.0%o, total coliforms were found in 72.1% of the samples and fecal coliforms constituted 66.0% of these. At salinities below 29.9%o, the respective values for total and fecal coliforms were 90.4% and 85.2%. These results strongly suggest that the detection of fecal coliforms is proportional to the amount of precipitation.

Growth Inhibition of Food-borne Bacteria by Juice and Extract of Ginger and Garlic (생강과 마늘 즙 및 추출물의 식중독 세균에 대한 증식저해작용)

  • 김미림;최경호;박찬성
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.2
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    • pp.160-169
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    • 2000
  • This study was conducted to understand the inhibitory garlic and ginger against the growth of food born pathogenic bacteria. Juice was prepared from the raw spices by using an electric homogenizer and membrane filter. Dry-powdered spices were treated with double distilled water and 70% ethanol to extract the antibacterial substances, respectively. Growth inhibitory effects of juice and extracts of the spices were monitored by using bacterial strains such as B. subtilis, L. moncytogenes, S. aureus,E. coli O157 : H7, P. aeruginosa, and S. typhimurium. On a solid medium where E. coli and S. aureus cells were grown, ginger juice formed inhibitory zone at the concentrations of 2-10% by paper disc test. The Bone formed by ginger juice was wider and more transparent than that formed by garlic juice on the same concentration.1. monocytogenes and B. subtilis were more sensitive to garlic juice than others, and stopped growing at 2% garlic juice. Ginger juice showed the growth inhibition by 30-50% at 1.0% concentration. On the contrast, P. aeruginosa which resisted to the garlic juice was the most sensitive to ginger juice. Water extract of garlic was not effective to inhibit the bacterial growth, while 2% ginger extract completely inhibited the growth of E. coli and S. aureus. Alcohol extract of ginger inhibited the growth of bacteria at the concentration of 0.3%. This growth inhibition is almost 10 times lower than that of the garlic extract. It was clear that ginger had more potential than garlic as an inhibitor to control the growth of the indicator organisms.

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Characterization of Melon necrotic spot virus Occurring on Watermelon in Korea

  • Kwak, Hae-Ryun;Kim, Jeong-Soo;Cho, Jeom-Deog;Lee, Joong-Hwan;Kim, Tae-sung;Kim, Mi-Kyeong;Choi, Hong-Soo
    • The Plant Pathology Journal
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    • v.31 no.4
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    • pp.379-387
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    • 2015
  • Melon necrotic spot virus (MNSV) was recently identified on watermelon (Citrullus vulgaris) in Korea, displaying as large necrotic spots and vein necrosis on the leaves and stems. The average occurrence of MNSV on watermelon was found to be 30-65% in Hapcheon and Andong City, respectively. Four isolates of the virus (MNSV-HW, MNSV-AW, MNSV-YW, and MNSV-SW) obtained from watermelon plants in different areas were non-pathogenic on ten general indicator plants, including Chenopodium quinoa, while they infected systemically six varieties of Cucurbitaceae. The virus particles purified by 10-40% sucrose density gradient centrifugation had a typical ultraviolet spectrum, with a minimum at 245 nm and a maximum at 260 nm. The morphology of the virus was spherical with a diameter of 28-30 nm. Virus particles were observed scattered throughout the cytoplasm of watermelon cells, but no crystals were detected. An ELISA was conducted using antiserum against MNSV-HW; the optimum concentrations of IgG and conjugated IgG for the assay were $1{\mu}l/ml$ and a 1:8,000-1:10,000 dilutions, respectively. Antiserum against MNSV-HW could capture specifically both MNSV-MN from melon and MNSV-HW from watermelon by IC/RT-PCR, and they were effectively detected with the same specific primer to produce product of 1,172 bp. The dsRNA of MNSV-HW had the same profile (4.5, 1.8, and 1.6 kb) as that of MNSV-MN from melon. The nucleotide sequence of the coat protein of MNSV-HW gave a different phylogenetic tree, having 17.2% difference in nucleotide sequence compared with MNSV isolates from melon.

Microbial Hazard Analysis of the Manufacturing Processes for Frozen Korean Cold Noodle, Naengmyeon (냉동 냉면류의 제조공정별 미생물학적 위해요소 평가)

  • Kim, YuJung;Kim, HyeJin;Lim, Youngeun;Yang, HuiJie;Park, Seulgi;Cheong, Jin-Sook;Om, Ae-Son
    • Journal of the FoodService Safety
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    • v.3 no.1
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    • pp.38-44
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    • 2022
  • This study investigated the microbiological hazards in the manufacturing processes of Naengmyeon. Sanitary indicative bacteria, such as aerobic plate counts and coliforms as well as pathogenic bacteria, were examined from raw materials, manufacturing processes, working area, 17 utensils and equipment. The aerobic plate counts for raw materials and arrowroot starch estimated as 0.77±0.68~5.02±0.28 and 5.02±0.28 log CFU/g, respectively. Coliforms were detected from wheat flour, buckwheat flour, and potato starch. Staphylococcus aureus was detected to be 0.61±1.06 log CFU/g in wheat flour and 0.20±0.35 log CFU/g in buckwheat flour. During the manufacturing process, aerobic plate counts for kneading process were 4.54±0.34 log CFU/g. But after the press out and heat process, contamination of aerobic plate counts and coliforms decreased and remained at a low level until the release process. Aerobic plate counts before washing disinfection of screw were 3.28±0.62 log CFU/100 cm2, the level of which was high in utensils and equipment that had contact with employees or water. These results represent not only an important indicator for the hygienic level but also a scientific basis for analyzing biological hazards, which lead to the introduction of HACCP for the production of safe and hygienic cold noodles processed by manufacturers.

Distribution of Foodborne Pathogens from Garlic Chives and Its Production Environments in the Southern Part of Korea (남부지방 부추와 재배환경의 식품매개병원균의 분포)

  • Jung, Jieun;Oh, Kwang Kyo;Seo, Seung-Mi;Yang, SuIn;Jung, Kyu-Seok;Roh, Eunjung;Ryu, Jae-Gee
    • Journal of Food Hygiene and Safety
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    • v.35 no.5
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    • pp.477-488
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    • 2020
  • Recently, foodborne illness outbreaks linked to fresh produce are being increasingly reported in the United States, the EU, and Korea as well. Some of this increase may be due to improved surveillance, increase in consumption, change in consumers' habits, and complex distribution systems. Garlic chive is a green, fresh-cut vegetable consumed year-round as a nutrition-rich herb in Korea. It is also prone to contamination with foodborne pathogens during pre-harvest, as amendment with high amounts of livestock manure or compost to soil is required in its cultivation. Our aim in this study was to evaluate microbial contamination of garlic chives, garlic chives cultivation soil, compost, and irrigation water in the southern part of Korea. Samples were collected in A, B, and C regions in 2019 and 2020, and 69, 72, 27, and 40 of garlic chives, soil, compost, and irrigated water, respectively, were analyzed for the presence of sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), Bacillus cereus, Staphylococcus aureus, pathogenic E. coli, E. coli O157:H7, Listeria monocytogenes, and Salmonella spp. In A, B, and C regions, levels of total aerobic bacteria, coliform, B. cereus, and S. aureus on all samples were between 1.14 and 8.83 log CFU/g, 0.43 and 5.01 log CFU/g, 0.41 and 5.55 log CFU/g, and 1.81 and 6.27 log CFU/g, respectively. B. cereus isolated from garlic chives and environmental samples showed β-hemolysis activity. Incidence of S. aureus in garlic chive and its production environments in 2020 was different from 2019. In this study, B. cereus and S. aureus were the only pathogenic microorganisms detected in all samples. As a result, this work suggests that continuous monitoring in the production and pre-harvest environment is required to improve hthe hygiene and safety of garlic chive.