• 한국식품영양과학회지
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• 제20권3호
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• pp.260-265
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• 1991

Salmonella/microsome assay system을 이용하여 N -nitrosodimethylamine (NDMA)의 돌연변이유발성을 검토하는 효과적인 방법과 비타민 C가 NDMA자체의 돌연변이유발과 nitrite와 2급아민으로부터의 NDMA 생성에 미치는 영향을 연구하였다. NDMA를 활성화시키기 위한 S9중 Aroclor1254로 induce시킨 hamster S9이 가장 효과가 있었으며 Aroclor 1254나 phenobarbital로 induce시킨 rat 59 mix에 의하여서는 활성화가 약하였다. DMSO와 ethanol에 NDMA를 녹였을 때는 돌연변이유발실험에서 저해효과가 나타났으나 phosphate buffer(pH 7. 4), 증류수, 95% methanol, Tween 80 + water(l : 4)는 저해 효과가 없었다. 비타민 C는 이미 생성환 NDMA에 대해서는 돌연변이 유발저해 효과를 나타내지 않았지만 nitrite와 2급 아민(dimethylamine)으로 부터의 NDMA 생성은 크게 저해하였다. 반응물에 비타민C를 첨가한 경우 Salmonella typhimurium TAl00의 revertant 수가 spontaneous숫자 수준으로 감소되었으며 HPLC를 이용한 NDMA의 분석에서도 거의 95% 까지의 정량적인 감소를 관찰할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제29권10호
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• pp.1543-1552
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• 2019

Salmonella is a common zoonotic and foodborne pathogen that causes high morbidity and mortality in developing countries. In this study, we established and validated a polymerase spiral reaction (PSR) assay which targeted the conserved invasion gene (invA) of Salmonella by SYBR Green I indicator methods. Subsequently, assays for determination of the optimal conditions for optimal specificity and sensitivity of PSR were performed. We performed comprehensive evaluations using loop-mediated isothermal amplification (LAMP) and real-time PCR. A total number of 532 samples of daily food were analyzed by PSR. Twenty-seven bacterial strains were tested in the specificity assay, from which positive results were obtained only for 14-Salmonella strains. However, none of the 13 non-Salmonella strains was amplified. Similarly with LAMP and real-time PCR, the detection limit of the PSR assay was 50 CFU/ml. The PSR method was also successfully applied to evaluate the contamination with Salmonella in 532 samples of daily food, corroborating traditional culture method data. The novel PSR method is simple, sensitive, and rapid and provides new insights into the prevention and detection of foodborne diseases.

• 약학회지
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• 제46권3호
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• pp.208-212
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• 2002

Dehydroevodiamine HCl (DHED), which is a component separated from Evodia rutaecarpa Bentham, has novel anticholinesterase and antiamnesic activities in the scopolamine-induced amnesia model. Several studies suggest that DHED might be an effective drug for the Alzheimer's disease and the vascular type of dementia. In order to evaluate the mutagenic potential of DHED, Salmonella typhimurium reversion assay, chromosomal aberration test on Chinese hamster lung cells, in vivo micronucleus assay using mouse bone marrow cells, and comet assay were performed. DHED did not increase the number of revertant in the reverse mutation test using Salmonella typhimurium TA1535, TA1537, TA98, TA100. DHED HCl, at concentration of 5 and 10 $\mu\textrm{g}$/mι, increased the number of chromosome aberrated Chinese hamster lung cells with 5 and 10％, respectively. In mouse micronucleus test, no significant increase in the occurrence of micronucleated polychromatic erythrocyte was observed in ICR mice orally administered with DHED. DHED was tested for ability to induce genotoxic effect in L5178Y cells (mouse lymphoma cells) using the single cell gel electrophoresis assay (comet assay). In comet assay, tail moment did not increase in L5178Y cells treated with 10, 100, 300 $\mu$M DHED.

• 한국축산식품학회지
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• 제38권4호
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• pp.727-736
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• 2018

In this study, an immuno-magnetic bead (IMB)-based assay was developed to simultaneously detect Escherichia coli, Staphylococcus aureus, and Salmonella spp. and was tested in four animal-derived foods: beef, ham, egg, and ricotta cheese. The IMB-based assay exhibited good specificity by binding to five E. coli serotypes [capture efficiency (CE) average (avg.) 90.4%], five S. aureus strains (CE avg. 91.4%), and five Salmonella serotypes (CE avg. 95.4%) but not binding to non-target bacteria (CE<10%). Furthermore, the assay detected all three pathogens with a detection limit of 10 CFU/g without the need for enrichment or additional platforms. Since the results demonstrated that the IMB-based assay can effectively separate and enrich target bacteria from a variety of animal-derived food matrixes, the assay exhibits good specificity for potential use in providing rapid, immunological, presumptive identification of pathogenic bacteria.

• Food Science and Biotechnology
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• 제16권5호
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• pp.778-782
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• 2007

This study assessed the effects of the antimicrobial substances sulforaphane, grapefruit seed extracts (GSE), and reuterin on the expression of Salmonella HilA and InvF virulence gene using a LacZY assay (${\beta}$-galactosidase assay) with hilA:lacZY and invF:lacZY fusion strains of Salmonella typhimurium SL1344. Salmonella was grown for 8 hr at $37^{\circ}C$ in the presence of diluted antimicrobial substances ($2\;{\mu}g/mL$ sulforaphane, $20\{\mu}g/mL$ GSE, and 0.26 mM reuterin) at concentrations that did not inhibit the cellular growth of Salmonella. Sulforaphane inhibited the expression of HilA and InvF by 50-90 and 20-80%, respectively. GSE also inhibited the expression of both genes, but to a lesser degree. Among the 3 antimicrobial substances, reuterin showed the least inhibition, which was abolished after 3-4 hr. None of the antimicrobial substances inhibited the ${\beta}$-galactosidase enzyme activity of S. typhimurium. The assay used in this study represents a very sensitive method for screening bioactive substances that inhibit the expression of virulence genes in Salmonella.

• Journal of Microbiology and Biotechnology
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• 제18권10호
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• pp.1689-1694
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• 2008

The ability to detect Salmonella spp. is essential in the prevention of foodborne illness. This study examined a Salmonella spp. detection method involving the application of immunomagnetic separation and immunoliposomes (IMS/IL) encapsulating sulforhodamine B (SRB), a fluorescent dye. A quantitative assay was conducted by measuring the fluorescence intensity of SRB that was produced from an immunomagnetic bead-Salmonella spp.-immunoliposome complex. The results indicated detection limits of $2.7{\times}10^{5}$ and $5.2{\times}10^{3}$ CFU/ml for Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) and Salmonella enterka subsp. enterka serovar Typhimurium (S. Typhimurium), respectivley. The signal/noise ratio was improved by using 4% skim milk as a wash solution rather than 2% BSA. In addition, higher fluorescence intensity was obtained by increasing the liposome size. Compared with the conventional plating method, which takes 3-4 days for the isolation and identification of Salmonella spp., the total assay time of to h only including 6 h of culture enrichment was necessary for the Salmonella detection by IMS/IL. These results indicate that the IMS/ IL has great potential as an alternative rapid method for Salmonella detection.

• Journal of Microbiology and Biotechnology
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• 제33권2호
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• pp.228-234
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• 2023

In this study, the performance of a gold biosensor combined with light microscope imaging system (GB-LMIS) was comparatively evaluated against enzyme-linked immunosorbent assay (ELISA) for detecting Salmonella under simulated chilling condition. The optimum concentration of antiSalmonella polyclonal antibodies (pAbs) was determined to be 12.5 and 100 ㎍/ml for ELISA and GBLMIS, respectively. GB-LMIS exhibited a sufficient and competitive specificity toward three tested Salmonella among only. To mimic a real-world situation, chicken was inoculated with Salmonella cocktail and stored under chilling condition for 48 h. The overall growth of Salmonella under chilling condition was significantly lower than that under non-exposure to the chilling condition (p < 0.05). No significant differences in bacterial growth were observed between brain heart infusion and brilliant green broth during the enrichment period (p > 0.05). Finally, both GB-LMIS and ELISA were employed to detect Salmonella at every 2-h interval. GB-LMIS detected Salmonella with a competitive specificity by the direct observation of bacteria on the sensor using a charge-coupled device camera within a detection time of ~2.5 h. GB-LMIS is a feasible, novel, and rapid method for detecting Salmonella in poultry facilities.

• 한국식품과학회지
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• 제30권2호
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• pp.450-455
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• 1998

한국에 널리 분포하고 있는 곰솔, 리기다, 잣나무, 적송의 에탄올추출물과 각 용매 분획물을 이용하여, in vitro assay로서 spore rec-assay와 Salmonella typhimurium reversion assay법으로 시료자체 변이원성 유무와 4가지 양성변이원 물질(MNNG, 4NQO, Trp-P-1 및 B(a)p)에 대한 돌연변이 억제효과를 고찰하였다. 곰솔, 리기다, 잣나무, 적송의 에탄올 추출물은 spore rec-assay와 S. typhimurium를 이용한 mutagenicity assay에서 변이원성을 나타내지 않았다. 돌연변이 억제 시험에서는 4가지 시료 모두 농도 증가에 따른 억제율을 나타내었고 또 각각의 시료들의 분획물 중 잣나무와 소나무의 에테르 분획물들이 간접변이원인 Trp-P-1의 변이원성에 대하여 다른 분획물에 비하여 높은 억제율을 보여주었다.

• 한국식품영양과학회지
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• 제38권1호
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• pp.19-24
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• 2009

식용 및 약용으로 예로부터 널리 이용하는 양송이버섯 추출물의 생리적 기능에 대한 활성을 탐색하기 위하여 양송이 버섯(Agaricus bisporus)의 에탄올 추출물의 항산화 효과와 Ames test를 통한 돌연변이 유발 억제능을 탐색하였다. 지질과산화물에 대한 단백질 보호효과를 알아본 결과, 양송이 버섯 에탄올 추출물은 MDA와 BSA의 교차결합 형성을 100mg/assay이었을 때 72.21% 저해하였다. $Fe^{2+}$에 의해 유도된 지질의 과산화에 대한 저해율은 2.0 mg/assay일 때 24.96% 였으며, DPPH 라디칼 소거 활성을 측정한 결과 1.0 mg/assay일 때 52.75%의 저해율을 보였으며 처리농도가 증가할수록 저해율은 증가하였다. $IC_{50}$ 값으로 항산화능의 상대적 비교를 하였을 때 양송이버섯 추출물은 DPPH 라디칼 소거 활성이 가장 강하였으며, 그 다음은 지질과산화 억제능이었고 MDA와 BSA의 교차결합 억제능이 가장 낮았다. Ames test를 이용하여 돌연변이 유발 억제능을 알아본 결과, 양송이버섯 에탄올 추출물은 Salmonella Typhimurium TA98 및 TA100 두 균주에서 직접작용 돌연변이능을 각각 100% 저해하여 매우 효과적이었다. 간접작용 돌연변이능 저해효과는 Salmonella Typhimurium TA98에서 86.09%, Salmonella Typhimurium TA100에서는 81.93%로 나타나 양송이버섯 에탄올 추출물은 직접, 간접작용 돌연변이능에 대한 저해효과가 우수하다고 사료된다. 본 연구 결과를 종합해 볼 때, 양송이버섯은 항산화성과 항돌연변이성이 우수하므로 기능성식품으로 개발할 수 있는 가능성이 있다고 본다.

• 한국식품위생안전성학회지
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• 제33권1호
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• pp.50-57
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• 2018

Salmonella는 전세계적으로 식중독을 유발하는 주요 원인 균으로서, 식중독을 유발하는 Salmonella를 신속하게 검출하는 방법은 식품 안전을 위한 중요한 도구이다. Real-time PCR은 식중독균을 검출하기 위한 신속검사법으로 널리 사용되어 왔다. 최근에는 NBS LabChip real-time PCR이라는 새로운 시스템이 칩타입으로 조작이 간편하며 초고속의 real-time PCR 시스템이라는 보고가 있었다. 본 연구에서는 살모넬라의 신속한 검출을 위하여 NBS LabChip real-time PCR에 기반하여 real-time PCR 반응 시간이 20분 이내인 검출법을 확인하고자 하였다. 프라이머와 프로브 설계를 위해 두 개의 타겟 유전자(invA, stn)가 선택되었으며, 특이도와 민감도(검출한계)를 평가함으로 개발된 검출법을 검증하고자 하였다. 본 연구에서는 특이도 검증을 위해 Salmonella 균주 42주와 Non-Salmonella 균주 21주를 포함하였으며, 본 방법으로 Salmonella 42주에 대해서만 정확하게 검출이 가능하였다. 검출한계는 살모넬라 genome DNA 기준으로 $10^1copies/{\mu}L$으며, 소시지에서는 4시간 증균 이후 접종균수로서 $10^1CFU/g$에서 $10^2CFU/g$까지 검출이 가능하였다. 본 연구에서 개발된 검출법은 신속한 식중독 원인조사에 활용될 수 있을 것으로 기대된다.