Quantitative Microbial Risk Assessment for Campylobacter jejuni in Ground Meat Products in Korea

Lee, Jeeyeon,Lee, Heeyoung,Lee, Soomin,Kim, Sejeong,Ha, Jimyeong,Choi, Yukyung,Oh, Hyemin,Kim, Yujin,Lee, Yewon,Yoon, Ki-Sun,Seo, Kunho,Yoon, Yohan Korean Society for Food Science of Animal Resource 2019 한국축산식품학회지 Vol.39 No.4

This study evaluated Campylobacter jejuni risk in ground meat products. The C. jejuni prevalence in ground meat products was investigated. To develop the predictive model, survival data of C. jejuni were collected at $4^{\circ}C-30^{\circ}C$ during storage, and the data were fitted using the Weibull model. In addition, the storage temperature and time of ground meat products were investigated during distribution. The consumption amount and frequency of ground meat products were investigated by interviewing 1,500 adults. The prevalence, temperature, time, and consumption data were analyzed by @RISK to generate probabilistic distributions. In 224 samples of ground meat products, there were no C. jejuni-contaminated samples. A scenario with a series of probabilistic distributions, a predictive model and a dose-response model was prepared to calculate the probability of illness, and it showed that the probability of foodborne illness caused by C. jejuni per person per day from ground meat products was $5.68{\times}10^{-10}$, which can be considered low risk.

Usefulness of $^{18}F$-FDG PET/CT for the Evaluation of Bone Marrow Involvement in Patients with High-Grade Non-Hodgkin's Lymphoma

Lee, Yukyung,Hwang, Kyung Hoon,Hong, Junshik,Park, Jinny,Lee, Jae Hoon,Ahn, Jeong Yeal,Kim, Ji Hyun,Lee, Haejun,Kim, Seog Gyun,Shin, Ji Young The Korea Society of Nuclear Medicine 2012 핵의학 분자영상 Vol.46 No.4

Purpose To assess the usefulness of $^{18}F$-fluorodeoxyglucose PET/CT in the detection of bone marrow (BM) involvement of high-grade non-Hodgkin's lymphoma (NHL). Methods One hundred twenty patients with newly diagnosed diffuse large B-cell lymphoma or peripheral T-cell lymphoma between January 2007 and June 2011, who received BM trephine biopsy and $^{18}F$-FDG PET/CT before chemotherapy, were included in this retrospective study. We reviewed their $^{18}F$-FDG PET/CT images and bone marrow biopsy (BMB) results. After reviewing the images, we reviewed the medical records and radiological findings of interesting patients. Results There were 23 $^{18}F$-FDG PET/CT scans in which the marrow was considered to be abnormal (either positive or equivocal), and 97 $^{18}F$-FDG PET/CT scans were regarded as having negative FDG uptake. Of 120 patients, 100 (83.3 %) had a concordant result of BM interpretation between $^{18}F$-FDG PET/CT and BMB, and the remaining 20 patients had discordant results. Among 23 patients with either positive or equivocal $^{18}F$-FDG PET/CT scans, 1 of 12 patients with 'positive' $^{18}F$-FDG PET/CT had a lymphomatous involvement on BMB. In contrast, 10 of 11 patients with 'equivocal' BM hypermetabolism were reported as having positive involvement by BMB. Patients with abnormal $^{18}F$-FDG PET/CT had significantly higher $mSUV_{highest}$ than those with normal FDG-PET/CT. Conclusions $^{18}F$-FDG PET/CT and BMB are complementary techniques in assessing the presence of BM involvement in patients with high-grade NHL. The increasing availability of $^{18}F$-FDG PET/CTwill raise the need for additional biopsy for FDG-avid lesions, especially in patients with negative standard BMBs. $^{18}F$-FDG PET/CT can be useful as a decision-making tool for determining whether to perform a standard BMB or targeted biopsy to the FDG-avid lesion as an initial staging procedure.A direct bone biopsy for FDGpositive bone lesions should be included in staging guidelines in future. In $^{18}F$-FDG PET/CT-negative cases, BMB is still a powerful procedure, but BMB alone is insufficient for full evaluation of BM.

UNC119a bridges the transmission of Fyn signals to Rab11, leading to the completion of cytokinesis

Lee, YuKyung,Chung, Sunglan,Baek, In Keol,Lee, Tae H.,Paik, Soon-Young,Lee, JooHun Landes Bioscience 2013 Cell cycle Vol.12 No.8

<P>Src family kinases (SFKs) regulate the completion of cytokinesis through signal transduction pathways that lead to the Rab11-dependent phosphorylation of ERK and its localization to the midbody of cytokinetic cells. We find that UNC119a, a known activator of SFKs, plays essential roles in this signaling pathway. UNC119a localizes to the centrosome in interphase cells and begins to translocate from the spindle pole to the spindle midzone after the onset of mitosis; it then localizes to the intercellular bridge in telophase cells and to the midbody in cytokinetic cells. We show that the midbody localization of UNC119a is dependent on Rab11, and that knocking down UNC119a inhibits the Rab11-dependent phosphorylation and midbody localization of ERK and cytokinesis. Moreover, we demonstrate that UNC119a interacts with a Src family kinase, Fyn and is required for the activation of this kinase. These results suggest that UNC119a plays a key role in the Fyn signal transduction pathway, which regulates the completion of cytokinesis via Rab11.</P>

Combination of Hydrophobic Filtration and Enrichment Methods for Detecting Bacillus cereus in Fresh-Cut Cabbage

Lee, Sujung,Choi, Yukyung,Lee, Heeyoung,Kim, Sejeong,Lee, Jeeyeon,Ha, Jimyeong,Oh, Hyemin,Lee, Yewon,Kim, Yujin,Yoon, Yohan,Lee, Soomin The Korean Society of Food Hygiene and Safety 2018 한국식품위생안전성학회지 Vol.33 No.5

본 연구에서는 신선편이 양배추 내 Bacillus cereus의 최적 증균 온도를 선정하고 증균배양액에 소수성필터를 적용하여 multiplex PCR의 검출률을 확인하였다. B. cereus 증균온도는 B. cereus 균주 5 개를 혼합하여 1 Log CFU/mL이 되도록 증균배지에 접종하고 $30^{\circ}C$, $37^{\circ}C$, $42^{\circ}C$에서 증균한 뒤 3시간 간격으로 MYP agar에 도말한 후 계수하여 선정하였다. 소수성필터 미적용 그룹은 B. cereus 균주 5 개를 혼합하여 신선편이 양배추에 접종한 뒤 최적 증균온도에서 증균하였으며, 증균배양액을 가열하여 DNA를 추출한 뒤 multiplex PCR을 진행하였다. 소수성필터 적용 그룹은 증균배양액을 소수성 필터에 적용하고 필터에 있는 균을 멸균증류수로 현탁한 뒤 가열하여 추출된 DNA로 multiplex PCR을 진행하였다. 증균온도 확인 결과, 6시간 증균 시 $42^{\circ}C$에서 증균된 샘플($5.4{\pm}0.3Log\;CFU/mL$)과 $30^{\circ}C$에서 증균된 샘플($4.6{\pm}0.6Log\;CFU/mL$) 간 유의차가 확인되었다(p < 0.05). 소수성필터 적용 유무에 따른 multiplex PCR 결과, 1 Log CFU/g 접종된 샘플의 검출률이 소수성 필터 적용 전 60%(3/5)에서 100%(5/5)로 향상되었다. 2 Log CFU/g 접종 샘플은 소수성필터 적용 전 80%(4/5)에서 소수성 필터 적용 후 100%(5/5)로 검출률이 증가하였으나, 3 Log CFU/g 접종 샘플은 소수성 필터 적용 전후 모두 100%(5/5)로 확인되었다. 이상의 결과를 통해 신선편이 양배추 내 B. cereus 검출 시 증균배양액에 소수성필터를 적용하고 multiplex PCR을 적용했을 때 신속하고 효율적인 검출이 가능할 것으로 판단된다. This study developed a rapid detection method for Bacillus cereus in fresh-cut cabbages. Fresh-cut cabbage samples were inoculated at 1-, 2- and 3-Log CFU/g, and pathogens were enriched in tryptic soy broth containing 0.15% polymyxin B at $30^{\circ}C$, $37^{\circ}C$, and $42^{\circ}C$ to determine the detection limit and appropriate enrichment temperature for multiplex PCR detection. Enriched bacterial cells in enrichment broth were collected in a hydrophobic filter prior to DNA extraction for multiplex PCR. Filters were resuspended in distilled water, and DNA was extracted from the suspension. DNA samples were further analyzed by multiplex PCR. Detection limit of multiplex PCR was 5-Log CFU/mL. B. cereus cell counts were higher (P < 0.05) at $42^{\circ}C$ than other temperatures. Detection rate of 1-, 2-, and 3-Log CFU/g inoculated samples were 60%, 80%, and 100% after enrichment respectively. However, when enriched samples were filtered with hydrophobic membrane filter, detection rates became 100%, regardless of inoculation level. Results indicate a combination of enrichment with hydrophobic filtration improves rapid detection efficiency of B. cereus in fresh-cut cabbage by multiplex PCR.

Rapid Detection of Escherichia coli in Fresh Foods Using a Combination of Enrichment and PCR Analysis

Yukyung Choi,Sujung Lee,Heeyoung Lee,Soomin Lee,Sejeong Kim,Jeeyeon Lee,Jimyeong Ha,Hyemin Oh,Yewon Lee,Yujin Kim,Yohan Yoon 한국축산식품학회 2018 한국축산식품학회지 Vol.38 No.4

The objective of this study was to determine the minimum enrichment time for different types of food matrix (pork, beef, and fresh-cut lettuce) in an effort to improve Escherichia coli detection efficiency. Fresh pork (20 g), beef (20 g), and freshcut lettuce (20 g) were inoculated at 1, 2, and 3 Log CFU/g of Escherichia coli. Samples were enriched in filter bags for 3 or 5 h at 44.5℃, depending on sample type. E. coli cell counts in the samples were enriched in E. coli (EC) broth at 3 or 5 h. One milliliter of the enriched culture medium was used for DNA extraction, and PCR assays were performed using primers specific for uidA gene. To detect E. coli (uidA) in the samples, a 3–4 Log CFU/mL cell concentration was required. However, E. coli was detected at 1 Log CFU/g in fresh pork, beef, and fresh-cut lettuce after 5, 5, and 3-h enrichment, respectively. In conclusion, 5-h enrichment for fresh meats and 3-h enrichment for fresh-cut lettuce in EC broth at 44.5℃, and PCR analysis using uidA gene-specific primers were appropriate to detect E. coli rapidly in food samples.

Development of User-Friendly Modeling Software and Its Application in Processed Meat Products

Lee, Heeyoung,Lee, Panho,Lee, Soomin,Kim, Sejeong,Lee, Jeeyeon,Ha, Jimyeong,Choi, Yukyung,Oh, Hyemin,Yoon, Yohan The Korean Society of Food Hygiene and Safety 2018 한국식품위생안전성학회지 Vol.33 No.3

본 연구에서는 육제품의 다양한 조건(포장, 저장온도, 염농도, 아질산염농도)에서의 식중독세균의 생장을 예측하는소프트웨어를 예측미생물학에 대한 지식이 부족한 비전문가도 손쉽게 이용할 수 있도록 개발하였다. 육제품에서의 식중독세균예측소프트웨어(FAME: Foodborne bacteria Animal product Modeling Equipment)는 Javascript와 HTML을 이용하여 개발하였으며, 육제품에 대한 카이네틱모델과 확률모델을 포함하고있다. FAME에서는 검증(validation) 기능을 포함하고 있으며, FAME에 탑재 되어있는 예측모델의 수식을 자유롭게 수정할 수 있도록 고안 하였다. FAME에는 포장조건, 온도, 염농도, 아질산염농도 조합에 따라 실험한 데이터를 카이네틱모델(5,400 데이터)과 확률모델(345,600 데이터)에 탑재하였다. 사용자가 FAME을 이용하여 육제품의 제조 조건을 소프트웨어에 입력하면, 시간에 따른 식중독세균의 생장패턴과 생장확률이 즉시 계산 되어진다. 따라서 예측 미생물학에 대한 전문 지식이 없는 비전문가라고 하더라도 FAME을 이용하여 직접 실험을 하지 않고도 육제품에서의 식중독세균의 생장을 쉽고 빠르게 예측할 수 있어, 육가공분야에서 매우 유용하게 사용되어 질 수 있을 것으로 판단된다. The objective of this study was to develop software to predict the kinetic behavior and the probability of foodborne bacterial growth on processed meat products. It is designed for rapid application by non-specialists in predictive microbiology. The software, named Foodborne bacteria Animal product Modeling Equipment (FAME), was developed using Javascript and HTML. FAME consists of a kinetic model and a probabilistic model, and it can be used to predict bacterial growth pattern and probability. In addition, validation and editing of model equation are available in FAME. The data used by the software were constructed with 5,400 frankfurter samples for the kinetic model and 345,600 samples for the probabilistic model using a variety of combinations including atmospheric conditions, temperature, NaCl concentrations and $NaNO_2$ concentrations. Using FAME, users can select the concentrations of NaCl and $NaNO_2$ meat products as well as storage conditions (atmosphere and temperature). The software displays bacterial growth patterns and growth probabilities, which facilitate the determination of optimal safety conditions for meat products. FAME is useful in predicting bacterial kinetic behavior and growth probability, especially for quick application, and is designed for use by non-specialists in predictive microbiology.

Development of User-Friendly Modeling Software and Its Application in Processed Meat Products

Heeyoung Lee,Panho Lee,Soomin Lee,Sejeong Kim,Jeeyeon Lee,Jimyeong Ha,Hyemin Oh,Yohan Yoon,Yukyung Choi 한국식품위생안전성학회 2018 한국식품위생안전성학회지 Vol.33 No.3

The objective of this study was to develop software to predict the kinetic behavior and the probability of foodborne bacterial growth on processed meat products. It is designed for rapid application by non-specialists in predictive microbiology. The software, named Foodborne bacteria Animal product Modeling Equipment (FAME), was developed using Javascript and HTML. FAME consists of a kinetic model and a probabilistic model, and it can be used to predict bacterial growth pattern and probability. In addition, validation and editing of model equation are available in FAME. The data used by the software were constructed with 5,400 frankfurter samples for the kinetic model and 345,600 samples for the probabilistic model using a variety of combinations including atmospheric conditions, temperature, NaCl concentrations and NaNO2 concentrations. Using FAME, users can select the concentrations of NaCl and NaNO2 meat products as well as storage conditions (atmosphere and temperature). The software displays bacterial growth patterns and growth probabilities, which facilitate the determination of optimal safety conditions for meat products. FAME is useful in predicting bacterial kinetic behavior and growth probability, especially for quick application, and is designed for use by non-specialists in predictive microbiology.

Combination of Hydrophobic Filtration and Enrichment Methods for Detecting Bacillus cereus in Fresh-Cut Cabbage

Sujung Lee,Yukyung Choi,Heeyoung Lee,Sejeong Kim,Jeeyeon Lee,Jimyeong Ha,Hyemin Oh,Yewon Lee,Yujin Kim,Yohan Yoon,Soomin Lee 한국식품위생안전성학회 2018 한국식품위생안전성학회지 Vol.33 No.5

본 연구에서는 신선편이 양배추 내 Bacillus cereus의 최 적 증균 온도를 선정하고 증균배양액에 소수성필터를 적용하여 multiplex PCR의 검출률을 확인하였다. B. cereus 증균온도는 B. cereus 균주 5 개를 혼합하여 1 Log CFU/ mL이 되도록 증균배지에 접종하고 30oC, 37oC, 42oC에서 증균한 뒤 3시간 간격으로 MYP agar에 도말한 후 계수하여 선정하였다. 소수성필터 미적용 그룹은 B. cereus 균 주 5 개를 혼합하여 신선편이 양배추에 접종한 뒤 최적 증균온도에서 증균하였으며, 증균배양액을 가열하여 DNA 를 추출한 뒤 multiplex PCR을 진행하였다. 소수성필터 적용 그룹은 증균배양액을 소수성 필터에 적용하고 필터에 있는 균을 멸균증류수로 현탁한 뒤 가열하여 추출된 DNA 로 multiplex PCR을 진행하였다. 증균온도 확인 결과, 6시간 증균 시 42oC에서 증균된 샘플(5.4 ± 0.3 Log CFU/mL) 과 30oC에서 증균된 샘플(4.6 ± 0.6 Log CFU/mL) 간 유의 차가 확인되었다(p < 0.05). 소수성필터 적용 유무에 따른 multiplex PCR 결과, 1 Log CFU/g 접종된 샘플의 검출률이 소수성 필터 적용 전 60%(3/5)에서 100%(5/5)로 향상 되었다. 2 Log CFU/g 접종 샘플은 소수성필터 적용 전 80%(4/5)에서 소수성 필터 적용 후 100%(5/5)로 검출률이 증가하였으나, 3 Log CFU/g 접종 샘플은 소수성 필터 적용 전후 모두 100%(5/5)로 확인되었다. 이상의 결과를 통해 신선편이 양배추 내 B. cereus 검출 시 증균배양액에 소수성필터를 적용하고 multiplex PCR을 적용했을 때 신속하고 효율적인 검출이 가능할 것으로 판단된다. This study developed a rapid detection method for Bacillus cereus in fresh-cut cabbages. Fresh-cut cabbage samples were inoculated at 1-, 2- and 3-Log CFU/g, and pathogens were enriched in tryptic soy broth containing 0.15% polymyxin B at 30oC, 37oC, and 42oC to determine the detection limit and appropriate enrichment temperature for multiplex PCR detection. Enriched bacterial cells in enrichment broth were collected in a hydrophobic filter prior to DNA extraction for multiplex PCR. Filters were resuspended in distilled water, and DNA was extracted from the suspension. DNA samples were further analyzed by multiplex PCR. Detection limit of multiplex PCR was 5-Log CFU/mL. B. cereus cell counts were higher (P < 0.05) at 42oC than other temperatures. Detection rate of 1-, 2-, and 3-Log CFU/g inoculated samples were 60%, 80%, and 100% after enrichment respectively. However, when enriched samples were filtered with hydrophobic membrane filter, detection rates became 100%, regardless of inoculation level. Results indicate a combination of enrichment with hydrophobic filtration improves rapid detection efficiency of B. cereus in fresh-cut cabbage by multiplex PCR.

Solution structure of human atrial natriuretic peptides (7-28)

Yukyung Lee(이유경),Yoongho Lim(임융호) 한국생물공학회 2005 한국생물공학회 학술대회 Vol.2005 No.10

QSAR study of DEVD derivatives as apoptotic inducer

Yukyung Lee,Haeyoung Lim,Chul-Hoon Lee,Yoongho Lim 한국생물공학회 2005 한국생물공학회 학술대회 Vol.2005 No.4