• 제목/요약/키워드: Cross-Contamination

검색결과 261건 처리시간 0.029초

인삼의 GAP 실천모델 개발을 위한 재배단계의 미생물학적 위해도 평가 (Microbiological Hazard Analysis of Ginseng Farms at the Cultivation Stage to Develop a Good Agricultural Practices (GAP) Model)

  • 심원보;김정숙;정덕화
    • 한국식품위생안전성학회지
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    • 제28권4호
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    • pp.312-318
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    • 2013
  • 본 연구는 인삼의 재배단계에서의 생물학적 위해요소를 조사하고 그 결과를 인삼 GAP 실천 모델의 개발을 위한 기초자료로 제공하기 위해 수행하였다. 충남 금산에 소재한 인삼 경작지 3곳에서 재배환경, 작물, 개인위생 항목에 대해 총 96점의 시료를 수집하여 위생지표세균, 병원성미생물, 그리고 곰팡이에 대해 분석하였다. 일반세균과 대장균군, 곰팡이의 오염도는 각각 1.3~6.0, 0.1~5.0 및 0.4~4.9 log CFU/g (or mL, hand, and $100cm^2$)으로 확인되었고, 대장균의 경우 C 농장의 농업용수에서 검출되었다. 병원성 미생물은 모든 시료에서 B. cereus만 0.1~4.9 log/g (or mL, hand, and $100cm^2$)범위로 검출되었으며, L. monocytogenes, E. coli O157:H7, Salmonella spp. 및 S. aureus는 검출되지 않았다. 이상의 결과 인삼 경작지 3곳은 미생물학적 위해요소에 대해서는 안전한 것으로 나타났으나, 주변 환경이나 작업자들에 의해 교차오염이 발생할 가능성은 항상 존재하므로 보다 안전성이 확보된 인삼을 재배하기 위해서 미생물학적 위해요소의 관리과 포함된 GAP 모델의 적용이 필요하다.

Multi-dimensional GC-MS를 이용한 항공터빈유의 FAME 함량 분석 (Determination of fatty acid methyl esters (FAME) content in aviation turbine fuel using multi-dimensional GC-MS)

  • 연주민;도진우;황인하;김성룡;강용
    • 한국응용과학기술학회지
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    • 제34권4호
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    • pp.717-726
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    • 2017
  • 항공유에 fatty acid methyl esters (FAME)가 혼합될 경우 연료 공급시스템과 항공기 엔진에 치명적인 고장의 원인이 될 수 있기 때문에 항공유 품질규격에서 FAME 함량을 50 mg/kg 이하로 규정하고 있다. 무수히 많은 탄화수소로 구성된 항공유 중의 FAME 성분을 선택적으로 분석하기 어렵기 때문에 본 연구에서는 MDGC-MS를 사용한 새로운 시험방법을 개발하였다. Deans switching 시스템이 설치된 MDGC-MS를 이용하면 코코넛 오일이나 팜유 유래의 저분자량 FAME 성분도 분석이 가능함을 확인하였다. 개발된 시험방법은 FAME 피크의 머무름 시간을 약간 뒤로 이동시키는 매질 효과(matrix effect)를 현행의 기준 시험방법(IP 585)보다 약 20배 이하로 감소시킬 수 있었다. MDGC-MS는 항공유에 미량의 FAME가 오염되었는지 여부를 정성 및 정량적으로 확인할 수 있는 시험방법으로 적합하였다.

낙동강 원수에 대한 대장균군 막여과시험법에 있어서 여러 인자가 결과에 미치는 영향 (The Influence of Various Factors upon the Membrane Filter Technique on Raw Water of the Nak-Dong River)

  • 현재열;윤종호;신상희;김종우
    • 한국물환경학회지
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    • 제25권2호
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    • pp.205-211
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    • 2009
  • In this study, the membrane filter method was compared to the MPN method for the analysis of total coliforms from raw water using raw test waters and controls including 6 standard strains of coliforms, and the various factors were analyzed on the detection of general and fecal origin coliforms. The range of error rate for the detection of 5 standard strains using the membrane filter and the MPN methods was 0 to 6% and 45 to 133%, respectively. The error rate of the membrane filter method was lower than that of the MPN method. The membrane filter method (m-Endo) showed 10% (11 out of 111) of difference for the detection sensitivity of coliforms isolated from raw water compared to the MPN method (BGLB). The membrane filter method was less affected by the factors including temperature, turbidity, charcoals of powder form, contamination, and reverse pressure. In conclusion, the membrane filter method is a better method for the analysis of total coliforms from raw water than the MPN method, considering the accuracy of detection and the tolerance to various experimental factors.

우리나라에서 보고된 집단 식중독의 발생 특징(1981-1989)

  • 홍종해;이용욱
    • 좋은식품
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    • 통권109호
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    • pp.34-40
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    • 1991
  • 1. 환자발생 규모는 10명 이하가 $38.0\%$로 가장 많았고 50명 이상의 대규모 발생도 $13.0\%$이었다. 대규모 환자발생은 세균성 식중독이 원인이었다. 2. 전체 식중독에 $67.3\%$가 7월부터 9월에 집중되어 계절의 변화에 영향받고 있음을 알 수 있다. Vibrio에 의한 발생은 특히 하절기에 높았고 Salmonella, Staphyloccus는 상대적으로 연중 계속해서 발생 가능성을 보였다. 독성물질에 의한 식중독은 계절과 무관하였으나 식물성 식중독은 7, 8월에 집중되고 있다. 3. 세균성 식중독이 $56.2\%$, 독성물질에 의한 식중독이 $17.8\%$이었다. 세균성 식중독의 원인균은 Vibrio $35.4\%$, Salmonella $27.2\%$, Escheri-chia coli $17.7\%$, Staphylococcus $17.7\%$ 순이었다. 독성물질에 의한 식중독은 식물성 식중독이 $64\%$로 가장 많았다. 4. Vibrio 식중독의 주원인식품은 해산물이지만 cross-contamination에 의해 오염된 다른 식품으로도 발생한 것으로 나타났다. Salmone-lla 식중독은 관혼상제시 거의 빠지지 않고 제공되는 돼지고기 편육이 주원인식품이었다. 5. 전체 식중독의 $76.8\%$가 가정과 식품접객업소(구내식당 포함)에서 발생되었으며, 특히 도시지역은 $66.4\%$가 식품접객업소에서 농촌지역은 $58.9\%$가 가정에서 발생되어 지역간의 차이를 보였다. 6. 독버섯은 독성물질에 의한 식중독의 주원인식품으로 농촌가정에서 일상식을 통한 섭취로 많이 발생되고 있으며, 사망자의 발생이 가장 많은 치명적인 원인식품이었다. 7. 식품접객업소에서 발생된 식중독의 주원인식품은 해산물이며, 덜익혀지거나 생선회 같이 날것을 섭취하여 발생하였다. 8. 생일잔치 및 회갑연, 결혼 피로연, 문상, 제사 등의 관혼상제시 발생되는 식중독은 농촌지역의 가정에서 주로 발생되고 있다. 구내 식당 및 관광지 음식점의 식중독 발생이 많은 것은 이들 시설에 대한 위생관리가 미비하여 대규모 식중독 발생의 위험이 항시 존재하고 있다고 할 수 있다.

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경남지역 위탁급식업체 조리종사자의 위생교육 및 근무환경에 따른 위생 직무수행도 평가 (A Study on the Hygiene Practices of Foodservice Employees by Hygiene Education and Work Environment in the Gyeongnam Area)

  • 임정희;김현아;정현영
    • 대한영양사협회학술지
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    • 제19권3호
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    • pp.209-222
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    • 2013
  • This study examined the hygiene practices of contract foodservice employees and investigated the influence of education and work environment on these hygienes practices. A questionnaire was distributed to 250 contract foodservice employees and a total of 232 responses were received and analyzed. The overall score for hygiene practices of contract foodservice employees was 3.89 based on a 5-point scale. Cross-contamination was prominent (highest score at 4.46) and the heating temperature was less prominent (lowest score at 3.49). The factors most affecting contract foodservice employees were their work period, the size of the contract foodservice management company, the number of meals served daily, the frequency of meal service per day and the frequency of hygiene education. Compared to small and medium-sized contract foodservice management companies, the major contract foodservice management companies showed higher scores for refrigerator/freezer control (P<0.001), vegetable/fruit disinfection (P<0.001), thawing (P<0.001), heating temperature (P<0.001), cleaning/disinfection (P<0.01), and personal hygiene (P<0.05). The frequency of hygiene education had a significant effect on the performance levels for refrigerator/freezer control (P<0.001), vegetable/fruit disinfection (P<0.001), thawing (P<0.001), heating temperature (P<0.001), cleaning/disinfection control (P<0.001), food supply control (P<0.05), and personal hygiene (P<0.05). From these results, to increase the sanitation quality of contract foodservice operations, hygiene practice levels need to increase and hygiene education systematically should be enforced for foodservice employees.

Practical application of DNA markers for high-throughput authentication of Panax ginseng and Panax quinquefolius from commercial ginseng products

  • Jung, Juyeon;Kim, Kyung Hee;Yang, Kiwoung;Bang, Kyong-Hwan;Yang, Tae-Jin
    • Journal of Ginseng Research
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    • 제38권2호
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    • pp.123-129
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    • 2014
  • Korean ginseng (Panax ginseng) and American ginseng (Panax quinquefolius) are widely used medicinal plants with similar morphology but different medicinal efficacy. Roots, flowers, and processed products of Korean and American ginseng can be difficult to differentiate from each other, leading to illegal trade in which one species is sold as the other. This study was carried out to develop convenient and reliable chloroplast genome-derived DNA markers for authentication of Korean and American ginseng in commercial processed products. One codominant marker could reproducibly identify both species and intentional mixtures of the two species. We further developed a set of species-unique dominant DNA markers. Each species-specific dominant marker could detect 1% cross contamination with other species by low resolution agarose gel electrophoresis or quantitative polymerase chain reaction. Both markers were successfully applied to evaluate the original species from various processed ginseng products purchased from markets in Korea and China. We believe that high-throughput application of this marker system will eradicate illegal trade and promote confident marketing for both species to increase the value of Korean as well as American ginseng in Korea and worldwide.

부산지역 중·고등학생 휴대전화에서 분리한 식중독균의 특성 연구 - 대장균, 황색포도상구균, 바실러스 세레우스를 중심으로 - (Study on the Characteristics of Food-borne Pathogens Isolated from Students' Mobile Phones in Busan)

  • 박선희;박연경;황인영;박혜영;성경혜;조현철
    • 한국환경보건학회지
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    • 제42권4호
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    • pp.255-265
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    • 2016
  • Objectives: Mobile phones have become one of the most essential accessories in daily life. However, they may act as reservoir of infectious pathogens if they are used without hygienic practices in their handling. Therefore, this study aimed to isolate food-borne pathogens from mobile phones and investigate the characteristics of toxin genes and antibiotic susceptibility patterns. Methods: A total of 146 mobile phones were collected from 83 middle- and 63 high-school students in Busan. The surfaces of the mobile phones were aseptically swabbed. Results: Among the food-borne pathogens, Staphylococcus aureus, Bacillus cereus and Escherichia coli were detected in 26 (17.8%), 20 (13.7%) and four (2.7%) samples, respectively. There were no statistically significant differences according to school level, gender or phone type. None of four E. coli strains had pathogenic toxic genes. All of the B. cereus strains carried at least three different toxin genes among the nine enterotoxin and emetic toxin genes. Three out of 20 B. cereus strains (15%) possessed emetic toxin genes, which are rarely detected in food-poisoning cases in Korea. Among the 26 strains of S. aureus, the detection rate of staphylococcal enterotoxin genes, toxic shock syndrome toxin (tsst) and factors essential for methicillin resistance (femA) were 84.6%, 7.7% and 100%, respectively. In the antibiotic susceptibility test, there was no methicillin-resistant S. aureus (MRSA) or vancomycin-resistant S. aureus (VRSA). Conclusion: The results show that students' mobile phones in Busan were contaminated by food-borne pathogens which carried various toxic genes. Therefore, regular phone disinfection and hand hygiene is important in order to reduce cross-contamination.

친수성 고무인상재의 침적 소독이 경석모형의 크기의 안정성과 표면경도에 미치는 영향 (EFFECT ON IMMERSI0N DISINFECTION OF HYDROPHIILIC RUBBER IMPRESSI0N MATERIAL ON DIMENSIONAL STABILITY AND SURFACE HARDNESS OF IMPROVED STONE CAST)

  • 남미현;강우진;정문규
    • 대한치과보철학회지
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    • 제33권3호
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    • pp.569-583
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    • 1995
  • Disinfection of dental impressions are necessary due to contamination with patient’s saliva and blood, which is a potential for cross-infection. The purpose of this study was to evaluate the effects of disinfection of four hydrophilic rubber impression materials with three disinfecting solutions, on the dimensional stability and surface hardness of improved stone casts. Three hydrophilic vinyl polysiloxane impression materials(Express, Reprosil, Exafine) and one polyether impression material(Impregum-F) were mixed according to the manufacturer’s directions and impressions were made on a ADA specification No. 19 stainless-steeldie. On removal of the impressions, each impression was immersed in one of the disinfectants(Banicide, Potadine, Clorox) for 10 minutes. After disinfection, type IV improved stone. casts were poured. On this cast, the linear dimension and surface hardness were measuredusing a Measurescope(Nikon, Japan) and a Barcol hardness tester(Barber, Colman Co U. S. A). The results were as follows : 1. The improved stone casts from disinfected Reprosil and Impregum-F impression material did not show dimensional changes(P>0.01). Those from disinfected Express and Exafine impression material showed dimensional changes(P<0.01). The amount of shrinkage was not clinically significant. 2. The improved stone casts from disinfected Express impression material did not exhibit changes in surface hardness(P>0.01), but those from disinfected Reprosil, Exafine, Imp regnum-F impression material showed changes in surface hardness(P<0.01). 3. The dimensinal stability and surface hardness of the improved stone casts were satisfactory using Banicide on Express, all disinfectants used in this study on Reprosil, Potadin and Clorox on Exafine, Banicide and Clorox on Impregum-F. According to these results, immersion disinfection of hydrophilic rubber impression mate rials did not adversely affect the resultant casts. Nevertheless compatibility tests of impression materials and disinfectants should be done when disinfecting impressions.

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Chemical Vapor Deposition of Ga2O3 Thin Films on Si Substrates

  • Kim, Doo-Hyun;Yoo, Seung-Ho;Chung, Taek-Mo;An, Ki-Seok;Yoo, Hee-Soo;Kim, Yun-Soo
    • Bulletin of the Korean Chemical Society
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    • 제23권2호
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    • pp.225-228
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    • 2002
  • Amorphous $Ga_2O_3$ films have been grown on Si(100) substrates by metal organic chemical vapor deposition (MOCVD) using gallium isopropoxide, $Ga(O^iPr)_3$, as single precursor. Deposition was carried out in the substrate temperature range 400-800 $^{\circ}C$. X-ray photoelectron spectroscopy (XPS) analysis revealed deposition of stoichiometric $Ga_2O_3$ thin films at 500-600 $^{\circ}C$. XPS depth profiling by $Ar^+$ ion sputtering indicated that carbon contamination exists mostly in the surface region with less than 3.5% content in the film. Microscopic images of the films by scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed formation of grains of approximately 20-40 nm in size on the film surfaces. The root-mean-square surface roughness from an AFM image was ${\sim}10{\AA}$. The interfacial layer of the $Ga_2O_3$/Si was measured to be ${\sim}35{\AA}$ thick by cross-sectional transmission electron microscopy (TEM). From the analysis of gaseous products of the CVD reaction by gas chromatography-mass spectrometry (GC-MS), an effort was made to explain the CVD mechanism.

High-throughput SNP Genotyping by Melting Curve Analysis for Resistance to Southern Root-knot Nematode and Frogeye Leaf Spot in Soybean

  • Ha, Bo-Keun;Boerma, H. Roger
    • Journal of Crop Science and Biotechnology
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    • 제11권2호
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    • pp.91-100
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    • 2008
  • Melting curve analysis of fluorescently labeled DNA fragments is used extensively for genotyping single nucleotide polymorphism(SNP). Here, we evaluated a SNP genotyping method by melting curve analysis with the two probe chemistries in a 384-well plate format on a Roche LightCycler 480. The HybProbe chemistry is based on the fluorescence resonance energy transfer(FRET) and the SimpleProbe chemistry uses a terminal self-quenching fluorophore. We evaluated FRET HybProbes and SimpleProbes for two SNP sites closely linked to two quantitative trait loci(QTL) for southern root-knot nematode resistance. These probes were used to genotype the two parents and 94 $F_2$ plants from the cross of PI 96354$\times$Bossier. The SNP genotypes of all samples determined by the LightCycler software agreed with previously determined SSR genotypes and the SNP genotypes determined on a Luminex 100 flow cytometry instrument. Multiplexed HybProbes for the two SNPs showed a 98.4% success rate and 100% concordance between repeats two of the same 96 DNA samples. Also, we developed a HybProbe assay for the Rcs3 gene conditioning broad resistance to the frogeye leaf spot(FLS) disease. The LightCycler 480 provides rapid PCR on 384-well plate and allows simultaneous amplification and analysis in approximately 2 hours without any additional steps after amplification. This allowed for a reduction of the potential contamination of PCR products, simplicity, and enablement of a streamlined workflow. The melting curve analysis on the LightCycler 480 provided high-throughput and rapid SNP genotyping and appears highly effective for marker-assisted selection in soybean.

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