• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.290-294
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• 2006

Inactivation rates of Salmonella enteritidis in vitro and in vivo were assessed using confocal microscopy and flow cytometry. S. enteritidis was inactivated with 1% (w/v) trisodium phosphate (TSP) and live cells, and inactive cells were distinguished by staining with fluorescent probe, LIVE/DEAD BacLight Bacteria Viability stain. After TSP treatment for 1 min, most of Salmonella cells changed from green (live cells) fluorescence to red (inactive cells) fluorescence, indication of effective sanitizing. Inactivation efficiency and contamination sites of S. enteritidis on chicken skin by TSP treatment were assessed using confocal laser microscopy. Precise flow cytometry histograms for viability changes of S. enteritidis. after TSP treatments were obtained. Efficiency of various sanitizer treatments on foodborne pathogens could be assessed using this method.

• Journal of Radiation Industry
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• v.5 no.1
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• pp.75-80
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• 2011

This study was to determine the microbiological safety and tensile strength of gammairradiated porcine tendon for the development of safe xenografts. Escherichia coli and Bacillus subtilis were used as model pathogens and inoculated as $10^6{\sim}10^7log$ colonies forming unit $(CFU)g^{-1}$. As model virus from porcine, porcine parvovirus (PPV), bovine viral diarrhoea virus (BVDV) and poliovirus were inoculated as $10^5{\sim}10^6$ tissue culture infectious dose $(TCID)_{50}g^{-1}$ into porcine skin. The $D_{10}$ value of E. coli and B. subtilis was measured as $0.32{\pm}0.082kGy$ and $4.0{\pm}0.312kGy$, respectively. Additionally, the $D_{10}$ values of PPV, BVDV and poliovirus were also shown as $1.75{\pm}0.131kGy$, $3.70{\pm}0.212kGy$ and $6.26{\pm}0.332kGy$, respectively. Gamma irradiation decreased the tensile strength of porcine tendon. Results indicate that microbiological safety of porcine tendon can be improved significantly by gamma irradiation. However, further studies are needed to improve the tensile strength of gamma-irradiated porcine tendon.

• Journal of Society of Preventive Korean Medicine
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• v.23 no.1
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• pp.27-47
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• 2019

Purpose : This study was designed to identify the perception and practice level of infection control among korean medical doctors and to identify factors that may influence the performance and practice level. Methods : Data were collected using the on­line survey method. Seven hundred and eighty four Korean medical doctors(KMD) participated the survey. The study was conducted from December 2018 to January 2019. Results : The results of this study are as follows. 1. Participants who experienced infection risk by needles or sharp instruments were 596(76%). and participants who had experienced blood or body fluid contact with the mucous membrane or skin of the patient during treatment were 226(28.8%) of them. 2. The degree of perception and practice of the infectious guideline was higher in the group over 50 years, in the doctor group, in the group with more than 6 years experience in clinic and in the group who work in the hospital. (p < 0.05) 3. In the performance of the infection control management related to the Korean medical treatment, the practice level of the article 'Discard the remaining needle that used for one patient' was the lowest at 4.02, 'Identify the patient and check the validity period of sterilization of medicines or instruments' was the second lowest in 4.16. 4. Among the contents of "Prevention of Nosocomial infection and Sanitary Safety Guidelines" issued by the Korean Medical Association in 2008, the guideline "Prevention of infection by pathogens such as HIV, MRSA, SARS" were lowest article in the perception and practice level of participants. 5. Regression analysis was performed to find out the factors affecting perception and performance of the participants. The regression model showed significant difference in the regression model of the working years. (p < 0.05) 6. In order to examine the effect of the variables on the perception and practice of the infectious guideline, the mediated effect of the knowledge and education level according to the years of working, age, education degree was found to be significant only in the education degree variable. (p < 0.05) In conclusion : in order to improve the perception and practice of infectious control of Korean medicine doctors, it is necessary to include the contents of infection management as essential education during the continuing education of Korean medicine association.

• Neonatal Medicine
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• v.18 no.2
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• pp.240-247
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• 2011

Purpose: The rationale for skin surface cultures is that bacterial colonization precedes infection and, as a result, that identification of a potential pathogen is predictive of later systemic infection in preterm infants. We aimed to analyze results of surveillance surface cultures in extremely low birth weight (ELBW) infants and seek for effective ways of performing surveillance surface cultures. Methods: We analyzed the surveillance surface cultures of 113 ELBW infants over a 4-year period. Surveillance cultures were obtained routinely from five sites: axilla, external ear canal, nasopharynx, throat (or tracheal aspirate if intubated) and anus. Each surface culture obtained during the 13 days, prior to the date of the blood culture, was compared with the blood culture obtained when sepsis was suspected. The sensitivity, specificity and positive predictive value (PPV) of the surveillance cultures were calculated among 1894 blood-surface culture pairs by surface sites, recovered organisms and interval between surveillance samples and blood cultures. Results: The overall sensitivity, specificity and PPV of surface cultures were 45.9, 22.4 and 6.8%, respectively. The PPV was highest for the throat/tracheal cultures (11.0%) and lowest for the anal cultures (2.3%). As the time of culturing progressed toward the day of blood culturing, the sensitivity and specificity of the surface cultures significantly increased. Only axillary and throat/tracheal cultures were useful in predicting the microorganisms causing sepsis. Conclusion: Surface cultures could help to predict sepsis pathogens and infection surveillance in preterm infants could be continued with a reduced number of cultured sites focusing on the axilla and throat/trachea.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.284-291
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• 2013

In this study, the antibacterial and antioxidative activities of Epimedium koreanum Nakai were investigated for applications as cosmetic ingredients. Minimum inhibitory concentrations (MICs) of fraction-bacterium, that showed high antibacterial activity from disc diffusion assay on human skin pathogens, were tested. The ethyl acetate fraction on Staphylococcus aureus, Bacillus subtilis, Propionibacterium acnes and 50% ethanol extract on S. aureus exhibited higher antibacterial activities than methyl paraben, well known as a preservative. The DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activities of 3 fractions of E. koreanum Nakai were lower than (+)-${\alpha}$-tocopherol, known as a typical antioxidant. From the results of the scavenging activities of various ROS generated in $Fe^{3+}-EDTA/H_2O_2$ systems ($OSC_{50}$), 50% ethanol extract ($OSC_{50}=2.46{\pm}0.06{\mu}g/ml$) and aglycone fraction ($OSC_{50}=1.45{\pm}0.02{\mu}g/ml$) showed high activities similar to L-ascorbic acid ($OSC_{50}=1.50{\pm}0.85{\mu}g/ml$), used as reference. The cellular protective effects (${\tau}_{50}$) on photohemolysis by $^1O_2$ generated by photosensitization reaction were tested. The cellular protective effect of 50% ethanol extract (${\tau}_{50}=37.0{\pm}0.3$ min) was similar to (+)-${\alpha}$-tocopherol (${\tau}_{50}=38.0{\pm}1.8$ min), used as reference. In particular, the ${\tau}_{50}$ of aglycone fraction results were $165.9{\pm}7.2$ min. This is a high cellular protective effect, more than 4 times that of (+)-${\alpha}$-tocopherol. These results indicate that E. koreanum Nakai extract, and its fractions, could be utilized as a cosmetic ingredient possessing antibacterial and antioxidative activities.

• Clinical and Experimental Pediatrics
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• v.49 no.2
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• pp.157-161
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• 2006

Purpose : The purpose of this study is to investigate the pathogens of central venous catheter-related blood stream infections and search for the association among the insertion site, the duration and the underlying conditions with the prevalence of central venous catheter-related blood stream infections under 15 years old. Methods : A retrospective study was performed from Jan, 2003 to Dec, 2003 in Severance Hospital on 112 patients who undertook central venous catheter insertions. Results : We examined 112 patients who undertook central venous catheter insertion. The mean age of patients was $4.77{\pm}4.12$ years old. Coagulase negative Staphylococci was the most common organism of central venous catheter-related blood stream infections accounting for 33.9 percent, followed by Eenterococcus faecium(9.3 percent), and Staphylococcus aureus(7.5 percent), The most common insertion site was the right femoral vein, followed by the right jugular vein and the left femoral vein. The mean insertion period was $14.17{\pm}12.00$ days. Conclusion : Central venous catheter-related blood stream infections were not only related to the underlying conditions, but also to the insertion site. We need to study the clinical importance of coagulase negative Staphylococci as it is part of the normal flora of the skin. In future, more studies are needed to take preventive measures and improve treatment methods.

• Microbiology and Biotechnology Letters
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• v.38 no.2
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• pp.168-176
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• 2010

Acellular dermal matrix (ADM), produced by decellularization from human cadaveric skin, has been used for various biomedical applications. A manufacturing process for ADM ($SureDerm^{TM}$) using tri-n-butyl phospahate (TnBP) and deoxycholic acids as the decellularization solution has been developed. The manufacturing process for $SureDerm^{TM}$ has 70% ethanol treatment and ethylene oxide gas sterilization for inactivating infectious microorganisms. The purpose of this study was to examine the efficacy of the 70% ethanol treatment, decellularization process using 0.1% TnBP and 2% deoxycholic acids, and EO gas sterilization process in the inactivation of viruses. A variety of experimental model viruses for human pathogens, including the human immunodeficiency virus type 1 (HIV-1), bovine herpes virus (BHV), bovine viral diarrhoea virus (BVDV), hepatitis A virus (HAV), and porcine parvovirus (PPV) were all selected for this study. Enveloped viruses such as HIV-1, BHV, and BVDV were effectively inactivated to undetectable levels by 70% ethanol treatment. However HAV and PPV showed high resistance to 70% ethanol treatment with the log reduction factors of 1.85 and 1.15, respectively. HIV-1, BHV, and BVDV were effectively inactivated to undetectable levels by decellularization process. All the viruses tested were completely inactivated to undetectable levels by EO gas treatment. The cumulative log reduction factors of HIV-1, BHV, BVDV, HAV, and PPV were $\geq12.71$, $\geq18.08$, $\geq14.92$, $\geq6.57$, and $\geq7.18$, respectively. These results indicate that the production process for $SureDerm^{TM}$ has a sufficient virus-reducing capacity to achieve a high margin of the virus safety.