• The Korean Journal of Food And Nutrition
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• v.28 no.5
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• pp.918-925
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• 2015

An investigation was conducted to evaluate the hygienic status of 33 high school foodservice systems in Yongin city by using hygiene management guide checklist, ATP bioluminescence assay and microbe inspection petrifilm (APC, coliform group, Staphylococcus aureus) of food utensils during use. The 22 hygiene management guide checklist items about facilities, personal hygiene, food control, distribution, washing and disinfection had good grade but there were some inadequate behaviors on observation. The inspection results showed their sanitary condition met the level B of the recommendation of Korea method, it means sanitary management system get settled but more practical CCP system was needed. ATP bioluminescence assay was conducted on surface of food facilities, ATP ranged 425~2,552 RLU on gloves, 541~70,251 RLU on apron, 1,596~88,490 RLU on working desk, 1,177~263,813 RLU on sterilizer grip, 715~32,814 RLU on sterilizer shelf, 114~619,725 RLU on refrigerator grip, 677~319,007 RLU on refrigerator shelf, 71~196,725 RLU on freezer grip, 1,535~233,375 RLU on freezer shelf. APC ranged $66.7{\pm}29.0CFU$ on freezer grip, $102.1{\pm}35.9CFU$ on refrigerator grip, $45.4{\pm}28.2CFU$ on heating cabinet grip, $58.8{\pm}40.4CFU$ on sterilizer grip, the number of coliform group ranged $5.6{\pm}4.9CFU$ on freezer grip, $9.1{\pm}8.7CFU$ on refrigerator grip, $1.2{\pm}1.1CFU$ on heating cabinet grip, $4.5{\pm}4.4CFU$ on sterilizer grip. S. aureus ranged $8.0{\pm}5.6CFU$ on freezer grip, $12.2{\pm}9.6CFU$ on refrigerator grip, $2.1{\pm}1.6CFU$ on heating cabinet grip, $11.6{\pm}6.4CFU$ on sterilizer grip.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.655-663
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• 2013

In this study, a rapid and sensitive detection tool for screening Salmonella spp. by using a loop-mediated isothermal amplification (LAMP) assay targeting the genomic sequence of the invA gene was developed. The inclusivity and exclusivity were both at 100% in the analysis, and the limit of detection (LOD) in a pure S. Enteritidis culture suspended in saline was $3.2{\times}10^3$ CFU/mL at 18.17 min ($R^2$ = 0.9446). The LODs of the LAMP assay in buffered peptone water with Salmonella (BPW) and duck carcass swab sample enriched in BPW with Salmonella (BPWS) after 0 and 12 h incubation were $3.2{\times}10^3$ CFU/mL and $3.2{\times}10^0$ CFU/mL, respectively. Comparing the LODs in BPW with those in BPWS, the LAMP assay was less influenced by compounds of duck carcass swab sample than the PCR assay. Sensitivity and specificity of the LAMP assay in 50 duck carcass swab samples enriched in BPW for 6 h were 96% and 84%, respectively, indicating that the LAMP assay is a rapid, simple and sensitive assay, which can be utilized as a potential screening tool of Salmonella spp. in duck carcass sample.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.862-868
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• 2014

Certain Escherichia coli (E. coli) strains have the ability to cause diarrheal disease. Five types of diarrheagenic E. coli have been identified, including EHEC, ETEC, EPEC, EAEC, and EIEC. To detect these five diarrheagenic types rapidly, we developed a one-step multiplex PCR (MP-PCR) assay using nine primer pairs to amplify nine virulence genes specific to the different virotypes, with each group being represented (i.e., stx1 and stx2 for EHEC, lt, sth, and stp for ETEC, eaeA and bfpA for EPEC, aggR for EAEC, and ipaH for EIEC). The PCR primers were constructed using MultAlin. The sensitivity and specificity of the constructed multiplex PCR primers were measured using DNA isolated from diarrheagenic E. coli strains representing each group. The limits of detection were as follows: $5{\times}10^1CFU/ml$ for EHEC, $5{\times}10^3CFU/ml$ for ETEC expressing lt and sth, $5{\times}10^4CFU/ml$ for ETEC expressing stp, $5{\times}10^2CFU/ml$ for EPEC, $5{\times}10^4CFU/ml$ for EAEC, and $5{\times}10^2CFU/ml$ for EIEC. To confirm the specificity, C. jejuni, C. perfringens, S. Typhimurium, V. parahaemolyticus, L. monocytogenes, Y. enterocolitica, B. cereus, and S. aureus were used as negative controls, and no amplification was obtained for these. Moreover, this kit was validated using 100 fecal samples from patients with diarrhea and 150 diarrheagenic E. coli strains isolated in Korea. In conclusion, the multiplex PCR assay developed in this study is very useful for the rapid and specific detection of five diarrheagenic E. coli types. This single-step assay will be useful as a rapid and economical method, as it reduces the cost and time required for the identification of diarrheagenic E. coli.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.191-197
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• 2005

An immunochromatographic (IC) strip for the rapid detection of Salmonella spp. in the enriched sample was developed. Affinity purified Salmonella polyclonal antibody was conjugated with 40 nm colloidal gold particles which were prepared by citrate method in our laboratory. The antigen-antibody-gold complex was captured by Salmonella antibody attached to test line of nitrocellulose membrane during the capillary migration of sample. Specificity of the IC strip was calculated to be 100% (12/12) and sensitivity was 97.6% (41/42) in the test with pure cultured bacteria. Salmonella was artificially inoculated into raw pork macerated with enrichment broth. And then it was 10-fold diluted from $5.2{\times}10^{8}CFU/ml$ to 5.2 CFU/ml. The IC strip could detect $5.2{\times}10^{6}CFU/ml$ before enrichment. However, the lowest limit of detection was 5.2 CFU/ml after overnight incubation. The results indicated that the IC assay was a rapid, economical and simple method with high specificity and sensitivity for the detection of Salmonella spp. without using any equipment.

• BioChip Journal
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• v.12 no.4
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• pp.287-293
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• 2018

Bacillus cereus can cause blood infections (i.e., sepsis). Its early detection is very important for treating patients. However, an antibody with high binding affinity to B. cereus is not currently available. Bacteriophage cell wall-binding domain (CBD) has strong and specific binding affinity to B. cereus. Here, we report the improvement in the sensitivity of an ATP bioluminescence assay for B. cereus detection using CBD-conjugated magnetic nanoparticles (CBD-MNPs). The assay was able to detect as few as 10 colony forming units (CFU) per mL and $10^3CFU\;per\;mL$ in buffer and blood. CBD-MNPs did not show any cross-reactivity with other microorganisms. These results demonstrate the feasibility of the ATP assay for the detection of B. cereus.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.569-573
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• 2010

A quantitative detection method for Salmonella in seafood was developed using a SYBR Green-based real-time PCR assay. The assay was developed using pure Salmonella DNA at different dilution levels [i.e., 1,000 to 2 genome equivalents (GE)]. The sensitivity of the real-time assay for Salmonella in seeded seafood samples was determined, and the minimum detection level was 20 CFU/g, whereas a detection level of 2 CFU/ml was obtained for pure culture in water with an efficiency of ${\geq}85%$. The real-time assay was evaluated in repeated experiments with seeded seafood samples and the regression coefficient ($R^2$) values were calculated. The performance of the real-time assay was further assessed with naturally contaminated seafood samples, where 4 out of 9 seafood samples tested positive for Salmonella and harbored cells <100 GE/g, which were not detected by direct plating on Salmonella Chromagar media. Thus, the method developed here will be useful for the rapid quantification of Salmonella in seafood, as the assay can be completed within 2-3 h. In addition, with the ability to detect a low number of Salmonella cells in seafood, this proposed method can be used to generate quantitative data on Salmonella in seafood, facilitating the implementation of control measures for Salmonella contamination in seafood at harvest and post-harvest levels.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.290-295
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• 2019

Salmonella spp. are frequently associated with food and are among the most important foodborne pathogens. The recent Salmonella out breaks in Korea was associated with chocolate mousse cakes served with school meals during September 2018. The objective of this research was to compare the 3M Molecular Detection Assay 2 - Salmonella and the Korean Standard Method of Salmonella in artificially inoculated mousse (chocolate and cheese) and tiramisu cakes. Mousse (chocolate and cheese) and tiramisu cakes were artificially inoculated with S. Typhimurium. Twenty five gram of sample was enriched with 225 mL buffered peptone water for incubation at $37^{\circ}C$ for 24 h. After enrichment, the cultures were analyzed by using the 3M Molecular Detection Assay 2 - Salmonella and the Korean Standard Method. Most of the inoculated samples showed similar results except the chocolate mousse cakes, in which real-time PCR was unable to detect S. Typhimurium even after $10^4CFU/25g$ of inoculation. However, S. Typhimurium inoculated at a concentration of $10^0CFU/25g$ was detected by using 3M Molecular Detection Assay 2 - Salmonella. In chocolate mousse, detection of S. Typhimurium using real-time PCR was partially successful when dark chocolate was added at less than 15%. Negative results in real-time PCR and 3M Molecular Detection Assay 2 - Salmonella were confirmed by gel electrophoresis. The data indicated that dark chocolate could inhibit amplification of the target gene in the PCR reactions. In conclusion, the 3M Molecular Detection Assay 2 - Salmonella was better than the Korean Standard Method (real-time PCR) for the detection of S. Typhimurium in chocolate mousse cakes and chocolate mousse.

• Journal of Aquaculture
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• v.21 no.1
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• pp.1-6
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• 2008

We determined the effects of dietary supplements for lactic acid bacteria(LAB) such as Lactobacillus brevis(Lb) and Lactobacillus plantarum(Lp) in juvenile rockfish Sebastes schlegeli cultured in flow-through system for 10 weeks. The experimental diets contained $10^4cfu/g,\;10^6cfu/g\;and\;10^8cfu/g$ level each LAB(Lb-4, Lb-6, Lb-8 or Lp-4, Lp-6, Lp-8), respectively. The effects of LAB supplementation was determined by various factor such as weight gain(WG), specific growth rate(SGR), feeding efficiency(FE) and blood assay. For rearing experiment, Lp-8 treatment had significantly high growth rate than control diet treatment. However, all Lb treatment had no significance effect with control diet treatment. In case of the blood assay, hematocrit(Ht) and hemoglobin(Hb) of fish were not affected by LAB supplemental levels. On the other hand, total cholesterol in plasma of Lb-8, Lp-6 and Lp-8 treatments were significantly low than the control diet treatment. We verified the influence of LAB which was originated from species specificity and amount in diet. Consequently, the dietary supplementation as $10^8cfu/g$ level of L. plantarum could be of help for growth enhancement to the juvenile rockfish.

• Food Science of Animal Resources
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• v.20 no.3
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• pp.231-235
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• 2000

원유에 존재하는 Ps. fluorescens의 균수를 신속하게 측정하기 위한 Inhibition Enzyme Linked Immunosorbant Assay (ELSIA)를 개발하기 위해 Ps, fluorescens(KCTC 2344)을 산란계에 접종하여 Ps.fluorescens에 대한 anti-Ps. fluorescens IgY 항체를 생산하고 그 항체의 역기를 ELISA로 측정한 결과 32일까지 항체 역가가 증가하였으며, 분리된 IgY 항체의 titer는 1:128,000으로 나타났다. Anti-Ps.fluorescens IgY 항체에대한 교차반응을 조사한 결과 그람양성균 Lactococcus faecalis, Staphylococcus aureus 뿐만 아니라 그람음성 균인 Achrombacter sal-monisida, Escherichia coil와도 교차반응을 거의 하지 않는 것으로 나타났다. Anti-Ps. fluo-rescens IgY 항체를 가지고 Inhibition ELISA 방법으로 Ps. fluorescens 균수를 신속한 측정할 수 있는 표준곡선을 작성한 결과 Ps. fluorescens균을 5.0$\times$$10^4$cfu/ml부터 5.0$\times$$10^{8}$cfu/ml 측정할 수 있는 것으로 나타났다.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.775-778
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• 2001

Chemokines are small chemotalic cytokines that have a number of biological functions. Some chemokines regulate the proliferation of hematopoietic stem and progenitor cells(HSPC). Leukotactin-l(Lkn-l) is a CC chemokine and is known to reduce colony forming unit(CFU). The N-terminal truncated Leukotactin-l(rtLkn-l), produced by Pichia pastoris, suppressed CFU from 40 to 60%. The rtLkn-l protected CFU from cytotoxic effect of anticancer drug such as Ara-C, doxorubicin, cyclophosphamide and 5-FU by cell cycle arrest.