• Title/Summary/Keyword: 병원성세균

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Rapid detection of shiga-toxin producing E. coli by bacteriophage amplification assay (박테리오파지 증폭 기법을 활용한 시가 독소 생성 병원성 대장균의 신속 검출)

  • Baek, Da-Yun;Park, Jong-Hyun;Cho, Seok-Cheol;Lee, Young-Duck
    • Korean Journal of Food Science and Technology
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    • v.52 no.1
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    • pp.103-108
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    • 2020
  • Shiga toxin-producing Escherichia coli (STEC) is an important pathogenic bacteria and can cause severe foodborne disease. For STEC detection, conventional culture methods have disadvantages in the fact that conventional culture takes a long time to detect and PCR can also detect dead bacteria. To overcome these problems, we suggest a bacteriophage amplification assay, which utilizes the ability of bacteriophages to infect living cells and their high specificity. We used a combination of six bacteriophages infecting E. coli to make the bacteriophage cocktail and added ferrous ammonium sulfate as a virucidal agent to remove free-bacteriophages. When cherry tomato and paprika were artificially inoculated with the cocktail at a final concentration of around 3 log CFU/mL and were enriched for at least 5 h in mTSB broth with Novobiocin, approximately 2-3 log PFU/mL were detected through the bacteriophage amplification assay. Therefore, bacteriophage amplification assay might be convenient and a useful method to detect STEC in a short period of time.

Identification of the Oligotrophic Bacteria Strain 7F Biocontrolling Phytophthora Blight Disease of Red-pepper (고추 역병 방제를 위한 저영양 길항세균 7F 균주의 동정)

  • Kim, Dong-Gwan;Yeo, Yun-Soo;Kwon, Soon-Wo;Jang, Kil-Su;Lee, Chang-Muk;Lee, Mi-Hye;Kim, Soo-Jin;Koo, Bon-Sung;Yoon, Sang-Hong
    • Research in Plant Disease
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    • v.16 no.1
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    • pp.41-47
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    • 2010
  • A total of 10,753 oligotrophic bacteria were isolated from the cultivated soils of red-pepper infected by Phytophthora blight disease in various regions of Korea (Chungju, Anmyon, Taean, Andong, Eumsung and Goesan). Seven bacteria isolates among these collected resources were selected by the first screening of in vitro antagonistic assay against major several plant pathogenic fungi including Phytophthora capsici. Finally, strain 7F was selected by pot assay for a possible biological control agent against Phytophthora blight disease of pepper seedling in the greenhouse. Strain 7F was identified as Bacillus subtilis on the basis of its 16S rDNA sequence analysis and as standardized biochemical characteristics assay kits such as API20 NE. In the experiment of P. capsici zoospore infected red-pepper on the pot test, infection rate of red-pepper with nonetreatment to Phytophthora blight disease was 87%, while the rate was only 6% in the pot treated with strain 7F. This result indicated that the Bacillus subtilis strain 7F will be useful as a potential biocontrol agent for Phytophthora blight disease of red-pepper.

Effects of Water-logging on the Chemical Properties, Microflora and Biomass in Continuous Cropping of Cucumber Soils (오이연작토양(連作土壤)의 화학성(化學性), 미생물상(微生物相) 및 Biomass 에 미치는 담수처리(湛水處理)의 영향(影響))

  • Kim, Hyun-Woo;Kim, Young-Woong;Kim, Kwang-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.22 no.2
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    • pp.146-155
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    • 1989
  • A series of the experiments were conducted to evaluate the effects of the water-logging in continuous cropping soils of cucumber. Some of the results obtained from these experiments are summarized as follow: The values of pH in water-logged treatments were from 5.50 to 5.90. Those of EC were less than 0.3 mmhos/cm, were lower than those of control plot. The ratios of Ca/Mg, Ca/K, Mg/K respectively 2.5, 4.8, 2.0, were similar to the standard values. These changes were suitable for cucumber planting. And the number of bacteria among the microflora were determined increased from $10^6$ to $10^7\;cells/g$ dry soil, while that of the Fungi, Fusarium spp, Pythium spp, and Phythophthora spp decreased. In proportion to these changes of microflora, the ratios of B/F in water-logging plot were higher than in the control plot. The contents of Biomass-C were showed 10.47mg/100g soil to 36.12 mg/100g soil, and the contents of that in water-logging were more than in control plots.

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Antifungal Mechanism of Pseudomonas stutzeri YPL-l for Biocontrol of Fusarium solani causing Plant Root Rot (식물근부균 Fusarium solani에 대한 Pseudomonas stutzeri YPL-1의 생물학적 방제기작)

  • 임호성;김상달
    • Microbiology and Biotechnology Letters
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    • v.18 no.1
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    • pp.81-88
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    • 1990
  • For the selection of powerful antagonistic bacterium for biological control of soilborne Fusarium solani causing root rot of many important crops, the best YPL-1 strain was selected among 300 strains of bacteria isolated from rhizosphere in ginseng root rot-suppressive soil. The strain was identified to be a species to Pseudomonas stutzeri. With in vitro fungal inhibition tests, antagonistic substance of P. stutzeri YPL-1 against F. solani was presumed to be heat unstable, macromolecular substances such as protein. Also, it was shown that antifungal activity of P. stutzeri YPL-1 increased in proportion to its chitinase production. P. stutzeri YPL-M122 (chi-, lam -) which was deprived of the productivity of chitinase and laminarinase by NTG mutagenesis had lost antifungal activity, completely. And P. stutzeri YPL-MI53 (chi-) had only 4.1% of its antifungal activity. P. stutzeri YPL-1 was not able to produce any extracellular siderophore in iron-deficent minimal medium. It is confident that the antifungal mechanism of P. stutzeri YPL-1 for biocontrol of F. solani depends on lysis rather than antibiosis :the mechanism of lysis appears to involve enzymatic degradation of the cell will components of F. solani by hydrolytic enzymes of more chitinase and less laminarinase.

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Confirmation of Saprophytes of Onions in Korea and Effects of Temperature, Humidity and Fumigation on Boyrytis-rot. (한국산 양파의 부패원인균 확인 및 Botrytis 부패에 대한 온도, 습도 및 훈증처리의 영향)

  • 이형춘;김현구;박무현;신동화
    • Microbiology and Biotechnology Letters
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    • v.12 no.4
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    • pp.299-304
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    • 1984
  • Saprophytic microorganisms of onion bulbs in Korea were confirmed, and effects of temperature, humidity and fumigation by Tetrachloro isophthalonitrile on Botrytis-rot were investigated in order to decrease storage loss of onions. Dominant saprophytes were Botrytis, Penicillium and Fusarium as molds which were all pathogens, and Erwinia and Pseudomonas as bacteria of which Pseudomonas was a non-pathogen. Botrytis-rot was most effectively suppressed by temperature. At $0^{\circ}C$, the incubation days at which 50% area of one onion leaf-fragment (2.5$\times$2.5cm) inoculated by Botrytis was rotten were 26.2 days and the rotting was delayed more by 21.8 days than at $25^{\circ}C$. For humidity, the effect was pretty insignificant in contrast with temperature effect. At RH 70% and $0^{\circ}C$, the incubation days at which 50% area of one onion leaf-fragment was rotten were 28.0 days and the rotting was delayed more by 1.8 days than at RH9o% and $0^{\circ}C$. By fumigation, the rotting was delayed by 3.8 days at RH 70% and $0^{\circ}C$. In case of slightly infected samples, temperature effect was reduced and the effects of humidity and fumigation were ignored, which implies that storage samples should be healthy.

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Studies on Biological Activities of the Polysaccharides and Oligosaccharides of Orostachys japonicus (와송 다당체 및 올리고당류의 생리 활성)

  • Kim Ki Hoon;Kim Eun Young;Kim Yea Oon;Baek Geum Ok;Kim Han Bok;Lee Dong Seok
    • Korean Journal of Microbiology
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    • v.40 no.4
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    • pp.334-341
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    • 2004
  • Polysaccharides were prepared from Orostachys japonicus by extration with hot steam water (OJPl). The OIPl fraction was further purified by Sephadex G-50 gel filtration chromatography to produce FI (polysaccharides) and FII (oligosaccharides) fraction. The average molecular masses o fFI and FII fraction were determined to be 3050 kDa and 13 kDa, respectively. The antimicrobial activity of OIPl was tested against 8 strains of bacteria and one strain of yeast by the disc diffusion method, fluorescein diacetate (FDA) method and broth dilution method. The OIPl exhibited a very strong growth inhibition to Candida albicans. The OIPl remarkably sup­pressed the growth of Salmonella typhimurium and Staphylococcus aureus. The OIPl showed higher growth inhibition to Escherichia coli and Pseudomonas aeruginosa than propolis, positive control. When the anticancer activity of the OIPl, FI or FII was examined against human cancer cell lines and the Sarcoma 180 cells, these widely suppressed the proliferation of cell lines in the MTT assay and morphology study. Especially, they remarkably inhibited the growth of A549, HeLa and AGS cells. Also treatment of cancer cells with OJPl, FI or FII induced apoptotic cell death characterized by DNA fragmentation. The OJPl, FI or FII exhibiting various biological activities such as antimicrobial activity and anticancer activity is expected to be developed as new biohealth products.

Antibiotic Resistance and Assessment of the Food-borne Pathogenic Microorganisms in Ready to Eat Meals (식사대용 식품(Ready-to-eat meals) 중 병원성 세균의 분포와 항생제 감수성 양상)

  • Hong, Eun-Kyung;Kim, Yun-A;Lee, Do-Kyung;Kang, Byung-Yong;Ha, Nam-Joo
    • Korean Journal of Microbiology
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    • v.42 no.4
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    • pp.265-270
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    • 2006
  • This study was performed in order to measure the level of food-borne pathogenic bacteria and antibiotic resistance pattern of found ready to eat meals such as Him-bap, Cho-bap, Hamburger, Sandwich and packed lunch boxes. A total of 497 samples were collected from supermarket and department of Seoul, Kyung-ki, Inctleon, Kang-won, Chung-Cheong from November, 2005 to March, 2006. The contaminated microorganisms were in most cases tract relative strain like E. coli and S. aureus. Result have shown E. coli was detected 4 strains and S. aureus was detected 22 strains. 26 strains were also tested the antibiotic resistance pattern. 26 strains were shown to be relatively susceptible to synercid, vancomycin, teicoplanin, ciprofloxacin, gentamycin, lincomycn, cefotaxime, meropenem, cephalosporin, amoxicillin-clavulanic acid by the MIC dilution method, but E. coli 1 strain was resistant to amoxicillin-clavulanic acid.

Impact of Climate Change on Yield Loss Caused by Bacterial Canker on Kiwifruit in Korea (기후변화 시나리오에 따른 미래 참다래 궤양병 피해 예측)

  • Do, Ki Seok;Chung, Bong Nam;Choi, Kyung San;Ahn, Jeong Joon;Joa, Jae Ho
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.2
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    • pp.65-73
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    • 2016
  • We estimated the averaged maximum incidences of bacterial canker at suitable sites for kiwifruit cultivation in 2020s and 2050s using D-PSA-K model with RCP4.5 and RCP8.5 climate change scenarios. Though there was a little difference between the estimation using RCP4.5 and that using RCP8.5, the estimated maximum disease incidences were more than 75% at all the suitable sites in Korea except for some southern coastal areas and Jeju island under the assumption that there are a plenty of infections to cause the symptoms. We also analyzed the intermediate and final outputs of D-PSA-K model to find out the trends on the change in disease incidence affected by climate change. Whereas increase of damage to kiwifruit canes in a non-frozen environment caused by bacterial canker was estimated at almost all the suitable sites in both the climate change scenarios, rate of necrosis increase caused by the bacterial canker pathogen in a frozen environment during the last overwintering season was predicted to be reduced at almost all the suitable sites in both the climate change scenarios. Directions of change in estimated maximum incidence varied with sites and scenarios. Whereas the maximum disease incidence at 3.14% of suitable sites for kiwifruit cultivation in 2020s under RCP4.5 scenario was estimated to increase by 10% or more in 2050s, the maximum disease incidence at 25.41% of the suitable sites under RCP8.5 scenario was estimated so.

Factors Related to Patients' Satisfaction Level of Treatment Outcome of Oral Malodor (구취치료 후 만족도에 영향을 미치는 예견인자)

  • Lee, Jeong-Yun;Kho, Hong-Seop;Kim, Young-Ku;Chung, Sung-Chang;Lee, Sung-Woo
    • Journal of Oral Medicine and Pain
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    • v.26 no.1
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    • pp.27-38
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    • 2001
  • 본 연구에서는 환자들에 의해 구취와 관련이 있다고 일반적으로 믿어지고 있는 여러 요인들이 치료 후의 환자의 만족도에 미치는 영향에 대해 알아봄으로써 환자의 만족도의 예후를 판단할 수 있는 자료를 마련하고자 하였다. 서울대학교 치과병원 구강진단과에 구취를 주소로 내원한 환자 194명을 대상으로 설문지를 이용하여 구취와 관련성이 있는 것으로 알려져 있는 항목들을 조사하였다. 조사 항목으로는 1) 본인확인가능여부, 2) 타인확인가능 여부, 3) 구취의 기간, 4) 구취의 빈도, 5) 축농증, 6) 비염, 7) 코수술 병력, 8) 콧물이 목뒤로 넘어감, 9) 코막힘, 10) 비호흡 곤란, 11) 구강건조감, 12) 편도선부종, 13) 가래, 14) 신물의 역류, 15) 소화불량, 16) 흡연여부가 포함되었다. 구취의 평가는 portable sulfide monitor인 $Halimeter^{(R)}$(Interscan Co., Chatsworth, CA, USA)를 이용하여 치료 전, 후에 각각 측정하였고, 혀배면의 세정, 치면 세균막 조절, 0.25% $ZnCl_2$ 양치액의 사용을 내용으로 하는 구취의 치료를 시행한 뒤 자신의 구취개선정도에 대해 %로 질문하여 치료 후 만족도를 조사하였다. 각 조사 항목과 치료 후 만족도 사이의 상관관계 및 실제 $Halimeter^{(R)}$ 수치의 개선정도와 만족도 사이의 상관관계를 분석하였으며, Symptom Checklist - 90 Revised(SCL-90R)의 분석결과에 따라 환자를 두 그룹으로 분류하고 두 그룹 사이의 치료 후 만족도의 차이를 조사한 결과 다음과 같은 결론을 얻었다. 1. 본인 및 타인 확인가능여부, 구취가 항상 나는지 여부, 구취의 기간, 축농증, 비염, 코수술 병력, 코막힘, 비호흡 곤란, 콧물이 목뒤로 넘어감, 흡연여부에 따른 치료 후 만족도의 유의한 차이는 없었다. 2. 신물의 역류(p=0.003), 소화불량(p=0.007), 구강건조감(p=0.016), 편도선 부종(p=0.018), 가래(p=0.033)에 따른 치료 후 만족도는 통계적으로 유의한 수준의 차이를 보였다. 3. $Halimeter^{(R)}$ 수치의 개선정도와 만족도 사이의 유의한 상관관계는 관찰되지 않았다(r=0.092, p=0.201).

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Antimicrobial effects of garlic extract against pathogenic bacteria (마늘추출물의 병원성 세균에 대한 항균 효과)

  • Lee, Woo-Won;Son, Soo-Kyeong;Lee, Gang-Rok;Kim, Geum-Hyang;Kim, Yong-Hwan
    • Korean Journal of Veterinary Service
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    • v.34 no.2
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    • pp.167-178
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    • 2011
  • Garlic (Allium sativum L.) has long history of reputed value and actual use for its medicinal, antimicrobial and pesticidal properties. This study was conducted to find possible developments to natural food preservatives and natural antimicrobials from garlic extracts. The antimicrobial activities of raw garlic extract, heat, pH, temperature against pathogenic bacteria were investigated. E. coli, S. Enteritidis, L. monocytogenes, and S. aureus exhibited antimicrobial activities at 20% garlic extract, but no antimicrobial activity was seen in E. faecium. Raw garlic extract and garlic extract heated for 2 min at $95^{\circ}C$ showed strong antimicrobial activities, but the antimicrobial activity of garlic extract heated for 10 min at $95^{\circ}C$ was much less. The antimicrobial activities of 50% garlic extract adjusted pH 4.0~7.0 showed much the same, but the antimicrobial activities decreased at pH 8.0 or higher. The antimicrobial activities by storage $-18^{\circ}C$ of garlic extract showed much the same. When five strains were cultured for 72 hr at $35^{\circ}C$ in the TSB containing 1~10% garlic extract, viable cell number of five strains were decreased to $10^0{\sim}10^4$ CFU/ml even at 1% or 2.5% (E. faecium) after 24 hr, but later increased to $10^4{\sim}10^9$ CFU/ml after 72 hr. When five strains were cultured for 21 day at $4^{\circ}C$ in the TSB containing 1%, 2.5%, 5%, and 10% garlic extract, viable cell number of E. coli, S. Enteritidis, and S. aureus were decreased to $10^3$, $10^0{\sim}10^2$, $10^1{\sim}10^4$ CFU/ml after 21 day, respectively, but L. monocytogenes and E. faecium increased to $10^8$ and $10^6$ CFU/ml after 21 day.