• Title/Summary/Keyword: disk method

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Antibacterial and Growth Inhibitory Effects of Liriope Platyphylla Ethanol Extract on Streptococcus Mutnas and Porphyromonas Gingivalis (맥문동 에탄올 추출물(Liriope platyphylla ethanol extract)의 Streptococcus mutnas와 Porphyromonas gingivalis에 대한 항균력과 성장억제 효과)

  • Su-Hyeon Chun;Ju-Yeon Park;Hyeon-Ji Lee;Ji-Eun Jeong;Eun-Suk Cha;Chung-Mu Park;Hyun-Seo Yoon
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.125-133
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    • 2023
  • Purpose : This study aimed to analyze the antibacterial activity of Liriope platyphylla ethanol extract (LPEE) against Streptococcus mutans and Porphyromonas gingivalis and to validate its potential for the prevention and treatment of dental caries, gingivitis, and periodontal disease. Methods : To verify the antibacterial effect of L. pulsatilla ethanolic extract (LPEE) against S. mutans and P. gingivalis, the disk diffusion method was used to determine the inhibition zones at concentrations of 50, 100, 200, and 300 mg/㎖. To determine the minimum inhibition concentration (MIC), the final dose of LPEE was .2, .4, .8, 1.6, 2.5, and 5.0 mg/㎖, and the minimum bactericidal concentration (MBC) was determined based on the MIC results. To confirm the growth inhibitory effect of LPEE on both pathogens, the absorbance was measured at 600 nm after each incubation for 0, 3, 6, 12, and 24 hr at concentrations of .8, 1.6, 2.5, and 5.0 mg/㎖. Results : The cytotoxicity of LPEE was evaluated and the cell viability was more than 70 % at 400 mg/㎖. Therefore, concentrations of 50, 100, 200, and 300 mg/㎖ were used in this study. The antimicrobial effect against S. mutans was seen at 100 mg/㎖ and grew in a concentration-dependent manner, while P. gingivalis was effective at 50 mg/㎖ with the dose dependency. The MIC was .8 mg/㎖ for both strains, and the MBC was 1.6 mg/㎖ with the same results. The growth inhibitory effect of LPEE on S. mutans and P. gingivalis was observed, even at low concentrations. Conclusion : The antibacterial effect of LPEE was evaluated through the analysis of MIC, MBC, and growth inhibition effect on S. mutans and P. gingivalis, which suggests LPEE might have the possibility of utilization as a preventive and therapeutic composition for oral diseases.

A Study on the Antifungal Properties of Ranunculaceae Herbal Medicines (미나리아재비과 한약재의 항진균성 검증 및 비교 연구)

  • Jae-yeoup Lim;Sang Ki Choi
    • Journal of Life Science
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    • v.34 no.6
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    • pp.393-398
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    • 2024
  • The purpose of this study was to verify the antifungal properties of various herbal medicines belonging to the Ranunculaceae family and to find an extraction method effective in inhibiting fungal growth. When antifungal activity was measured in a liquid medium with extracts obtained by either hot water extraction or organic solvent extraction of the herbal medicines Clematis apiifolia, Coptis chinensis, and Pusatilla chinensis, effective results were obtained from the chloroform extract. In addition, fungal growth inhibition experiments were performed on unicellular fungi, Candida albicans, Candida tropicalis, and Candida lusitaniae, and on filamentous fungi, such as Pythium ultimum, Aspergillus fumigatus, and Fusarium oxysporum, using disk diffusion experiments on solid media. It was confirmed that P. chinensis extract has excellent antifungal properties against Candida spp. and C. apiifolia extract against filamentous mold. Finally, GC-MS analysis was performed to explore the useful antifungal substances present in the extract. As a result of the study, thurbergenone from C. apiifolia and 16-hydroxycleroda-3, 13(14)-dien-15, 16-olide (16-HCDO) from C. chinensis were confirmed as antifungal candidates. In conclusion, it was confirmed that C. apiifolia, C. chinensis, and P. chinensis have antifungal activity against various fungi, and in GC-MS analysis, all herbal medicines were confirmed to have different antifungal candidates. These results indicate that the Ranunculaceae family has evolved in several directions for fungal resistance traits.

Comparison of Molecular Characterization and Antimicrobial Resistance in Carbapenem-Resistant Klebsiella pneumoniae ST307 and Non-ST307 (Carbapenem 내성 Klebsiella pneumoniae ST307과 Non-ST307의 분자 특성 및 항균제 내성 비교)

  • Hye Hyun Cho
    • Microbiology and Biotechnology Letters
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    • v.51 no.4
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    • pp.500-506
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    • 2023
  • Carbapenem-resistant Klebsiella pneumoniae (CRKP) is emerging as a worldwide public health threat. Recently, Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing sequence type (ST) 307 was identified main clone of CRKP, and dissemination of ST307 was reported in South Korea. This study examined the molecular characteristic and antimicrobial resistance pattern of 50 CRKP isolated from a tertiary hospital in Daejeon, from March 2020 to December 2021. Epidemiological relationship was analyzed by Multilocus sequence typing (MLST) and antimicrobial susceptibility test was determined using disk-diffusion method. PCR and DNA sequence analysis were performed to identify carbapenemase genes. CRKP infections were significantly more frequent in males and the patients aged ≥ 60 years. Among the 50 CRKP isolates, 46 isolates (92.0%) were multidrug-resistant (MDR), and 44 isolates (88.0%) were carbapenemase-producing K. pneumoniae (CPKP). The major carbapenemase type was KPC-2 (36 isolates, 72.0%) and New Delhi metalloenzyme-1 (NDM-1) and NDM-5 were identified in 7 isolates (14.0%) and 1 isolate (2.0%), respectively. In particular, 88.9% (32/36) of KPC-2-producing K. pneumoniae belonged to ST307, whereas 87.5% (7/8) of NDM-1,-5-producing K. pneumoniae belonged to non-ST307. These results suggest that proper infection control and effective surveillance network need to prevent not olny the spread of ST307, but also the development of non-ST307.

Molecular Genetic Characteristics of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated From Nasal Cavity of University Students (대학생들의 비강으로부터 분리된 메티실린 내성 황색포도알균의 분자유전학적 특성)

  • Lee Eun gwang;Oh Dae Hwan;Sunjin Jung;Sohyun Park;Yeonim Choi
    • Journal of the Health Care and Life Science
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    • v.9 no.2
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    • pp.303-308
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    • 2021
  • Staphylococcus aureus and methicillin resistant S. aureus (MRSA) is a major cause of nosocomial infections and is one of the most commonly isolated bacterial species in the hospital and continues to be an important pathogens in both community and hospital-acquires infection. The purpose of this study is to investigate the carrier rate of S. aureus and MRSA in the community and molecular genetic characteristics of these organisms. The identification of S. aureus and MRSA were done by the procedures in Murray's manual of Clinical Microbiology and antibiotic susceptibility patterns by the Clinical and Laboratory Standards Institute(CLSI). MRSA strains were confirms by oxacillin disk diffusion method. forty-six strains (71.9%) of S. aureus were isolated from the nasal specimens of 64 students in health science university. twenty-two strains (22%) of 46 S. aureus were resistant to penicillin and oxacillin. twenty-two strains of the 46 S. aureus isolates were methicillin-resistant Staphylococcus aureus (MRSA). The mecA genes in MRSA were detected by polymerase chain reaction (PCR). Community and nosocomial infections caused by methicillin-resistant Staphylococcus aureus are a significant problem worldwide. There continuous epidemiological study is to investigate the prevalence of MRSA in community acquired infections.

The Effect of Blast Drying System on Garlic just after Harvest (마늘의 수확직후(收穫直後)의 열풍건조(熱風乾燥) 효과(效果))

  • Lee, Woo Sung;Lee, Byung Chul
    • Current Research on Agriculture and Life Sciences
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    • v.1
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    • pp.151-158
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    • 1983
  • This study was performed to obtain a basic materials for improvement of garlic storage ability. The "Namhae jaerae" of southern strain and the "Dalsung jaerae" of northern strain were harvested by period, their stems were cut at 7cm and 25cm from disk and then placed them in blast drying system 12 hours per day at $40^{\circ}C$ for 4 days, or in natural state. The decrease rate of bulb weight was compared and rooting, sprouting, the rate of decay was investigated between natural dry(conventional method) and hot-air dry (blast drying system). The results obtained were as follows. In the case of the decrease rate of bulb weight after hot-air dry; 7cm plot" "Namhae jaerae" was similiar to one of 13th day of natural dry and 25cm plot 14th day. In "Dalsung jaerae" 7cm plot of early, common and late harvest was respectively similiar to one of 22nd, 18th and 16th day of natural dry, 25cm plot of early, common and late harvest showed the same decrease rate of bulb weight as that of 18th, 16th and 14th day of natural dry respectively. In the case of rooting and sprouting in sand culture at the early period of storage, hot-air dry showed more prolonged tendency than conventional drying method. In the case of clove state in the latter period of storage, number of eatable cloves was more numerous and number of decayed cloves were less in blast drying system than in conventional method.

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An Evaluation of the Rapid Antimicrobial Susceptibility Test by VITEK MS and VITEK 2 Systems in Blood Culture (혈액배양에서 VITEK MS와 VITEK 2 System을 이용한 신속 항생제 감수성 시험의 유용성 평가)

  • Park, Kang-Gyun;Yu, Young-Bin;Yook, Keundol;Kim, Sang-Ha;Kim, Sunghyun;Kim, Young Kwon
    • Korean Journal of Clinical Laboratory Science
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    • v.49 no.3
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    • pp.279-284
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    • 2017
  • The results of rapid antimicrobial susceptibility test (AST) in blood cultures were obtained by inoculating the bacteria directly into the VITEK MS and the VITEK 2 systems without subculturing in the blood culture positive medium. The obtained results were compared with the results using a standard method to evaluate their reliability and accuracy. The direct AST results in blood culture positive specimens were 97.9% (1,936/1,978), consistent with the standard AST results. Gram-positive bacteria showed a concordance rate of 97.2% (1,051/1,081), a very major error rate of 0.5% (5/1,081), a major error rate of 0.1% (1/1,081), and a minor error rate of 2.2% (24/1,081). Staphylococcus epidermidis was the main cause of discordance, and gentamicin (N=9) and fusidic acid (N=8) showed high errors. The overall concordance rate and minor error among the Gram-negative bacteria were 98.6% (885/897) and 1.4% (12/897), respectively. Escherichia coli and Pseudomonas aeruginosa were the major causative bacteria of Gram-negative bacteria. Among them, amoxicillin/clavulanic acid (N=3) showed high error. Direct AST met the CLSI criteria and shortened the reporting time by 24 hours; however, we found that there was a need to perform an addition test via disk diffusion for antimicrobials with very large errors. These results suggest that the method of direct AST in blood culture positive medium may be very useful in efficiently treating patients.

A Study of Image Quality Improvement Through Changes in Posture and Kernel Value in Neck CT Scanning (경부 CT검사 시 Kernel 값과 검사자세 변화를 통한 화질개선에 관한 연구)

  • Kim, Hyeon-Ju;Chung, Woo-Jun;Cho, Jae-Hwan
    • Journal of the Korean Society of Radiology
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    • v.5 no.2
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    • pp.59-66
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    • 2011
  • There is a difficulty because of classifying the anatomical structure in the neck CT scan by the beam hardening artifact no more than disease and it including the 6, 7 number cervical spine and intervertebral disk. In case of enforcing the neck CT scan cause of the inner diameter of beam artifact tried to be inquired by the image evaluation according to the change of the image evaluation according to the direction of the shoulder joint applying the variation method of a posture and location and Kernel value and it was most appropriate, the lion tax and Kernel value try to be searched for through an experiment. Somatom Sensation 16 (Siemens, Enlarge, Germany) equipment was used in a patient 30 people coming to the hospital for the neck CT scan. A workstation used the AW 4.4 version (GE, USA). According to a direction and location of the shoulder joint, the patient posture gave a change to the direction of the shoulder joint as the group S it gave a change as three postures and placed the both arms comfortably and helps a group N and augmented unipolar left in the wealthy merchant and group P it memorized the both hands and ordered the eversion and drops below to the utmost and enforced a scan. By using a reconstructing method as the second opinion, it gave and reconstructed the Kernel value a change based on scan data with B 10 (very smooth), B 20 (smooth), B 30 (medium smooth), B 40 (medium), B 50 (medium sharp), B 60 (sharp), and B 70 (very sharp). By using image data which gave the change of the examination posture and change of the Kernel value and are obtained, we analyzed through the noise value measurement and image evaluation of. The outside wire eversion orders the both hands and the examination posture is cost in the neck CT scan with the group P it drops below to the utmost. And in case of when reconstructing with B 40 (medium) or B 50 (medium sharp) being most analyzed into the inappropriate posture and Kernel value and applying the Kernel value to a clinical, it is considered to be very useful.

The Protective Role of Gleditsiae fructus against Streptococcus pneumoniae (폐렴 구균에 대한 조협의 보호 역할 연구)

  • Jun-ki Lee;Se-Hui Lee;Dong Ju Seo;Kang-Hee Lee;Sojung Park;Sun Park;Taekyung Kim;Jin-Young Yang
    • Journal of Life Science
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    • v.33 no.2
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    • pp.158-168
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    • 2023
  • Natural products have been used to mitigate the effects of cancer and infectious diseases, as they feature diverse bioactivities, such as antioxidant, antibacterial, anti-inflammatory, and immunomodulatory effects. Here, we chose 10 natural products that are well-known as pulmonary enhancers and investigated their bactericidal effects on Streptococcus pneumoniae. In the disk diffusion assay, the growth of S. pneumoniae was significantly regulated by G. fructus treatment regardless of extraction method used. We first adopted spraying as a novel delivery method for G. fructus. Interestingly, mice exposed to G. fructus three times a day for 2 weeks were resistant to S. pneumoniae intranasal infection (shown both through body weight loss and survival rates compared to the control group). Moreover, we confirmed that exposure to G. fructus regulated the colonization of the bacteria despite the sustained inflammation in the lung after exposure to S. pneumoniae, indicating that migrated inflammatory immune cells may involve a host defense mechanism against pulmonary infectious diseases. While a similar number of granulocytes (CD11b+Ly6C+Ly6G+), neutrophils (CD11b+Ly6CintLy6G+), and monocytes (CD11b+Ly6CintLy6G-) were found between groups, a significantly increased number of alveolar macrophages (CD11b+CD11chiF4/80+) was detected in BAL fluids of mice pre-exposed to G. fructus at 5 days after S. pneumonia infection. Taken together, our data suggest that this usage of G. fructus can induce protective immunity against bacterial infection, indicating that facial spray may be helpful in enhancing the defense mechanism against pulmonary inflammation and in evaluating the efficacy of natural products as immune enhancers against respiratory diseases.

Application of the Extract of Zanthoxylum piperitum DC to Manufacturing Eco-friendly Nosocomial Infection Control Protective Materials (초피의 항균 활성을 이용한 원내 감염 제어 친환경 방호 소재 개발)

  • Shin Young Park;Ki Yun Kim;Do Youn Jun;Sung Chul Kim;Hyo-Il Jung;Young Ho Kim
    • Journal of Life Science
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    • v.33 no.10
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    • pp.820-827
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    • 2023
  • Since COVID-19 began at the end of 2019, the wearing time of protective clothing used to prevent pathogenic bacteria and virus infection has increased, and the development of safe protective materials that are human-friendly and have antibacterial and antiviral functions has been required. In this study, we investigated the possibility of developing natural antibacterial protection materials using ethanol extract of the medicinal plant Zanthoxylum Piperitum DC. The antibacterial activity assay of the 80% ethanol extract of Z. piperitum DC leaves against various nosocomial infectious bacteria, using the disk diffusion method, showed that Staphylococcus aureus ATCC 25923, Klebsiella pneumoniae ATCC 13883, Salmonella typhimurium, and Aeromonas hydrophila are sensitive to the inhibitory action of the extract. The IC50 values of the ethanol extract against S. aureus, K. pneumoniae, P. vulgaris and A. hydrophila were about 0.59 mg/ml, 0.50 mg/ml, 1.06 mg/ml, and 0.06 mg/ml, respectively. To determine whether the ethanol extract of Z. piperitum DC leaves can be applied to the development of antibacterial protective fabric, the ethanol extract was tested using a protective fabric from the KM Health Care Corp. using the JIS L1902-Absorption method. As a result, the bacteriostatic and bactericidal activity values of S. aureus ATCC 25923 and K. pneumoniae ATCC 13883 appeared to be more than 2.0 when treated with the ethanol extract at a concentration of 1% (w/v). Together, these results suggest that Z. piperitum DC leaves can be applied to develop natural antibacterial functional protective fabrics.

Speed-up Techniques for High-Resolution Grid Data Processing in the Early Warning System for Agrometeorological Disaster (농업기상재해 조기경보시스템에서의 고해상도 격자형 자료의 처리 속도 향상 기법)

  • Park, J.H.;Shin, Y.S.;Kim, S.K.;Kang, W.S.;Han, Y.K.;Kim, J.H.;Kim, D.J.;Kim, S.O.;Shim, K.M.;Park, E.W.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.3
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    • pp.153-163
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    • 2017
  • The objective of this study is to enhance the model's speed of estimating weather variables (e.g., minimum/maximum temperature, sunshine hour, PRISM (Parameter-elevation Regression on Independent Slopes Model) based precipitation), which are applied to the Agrometeorological Early Warning System (http://www.agmet.kr). The current process of weather estimation is operated on high-performance multi-core CPUs that have 8 physical cores and 16 logical threads. Nonetheless, the server is not even dedicated to the handling of a single county, indicating that very high overhead is involved in calculating the 10 counties of the Seomjin River Basin. In order to reduce such overhead, several cache and parallelization techniques were used to measure the performance and to check the applicability. Results are as follows: (1) for simple calculations such as Growing Degree Days accumulation, the time required for Input and Output (I/O) is significantly greater than that for calculation, suggesting the need of a technique which reduces disk I/O bottlenecks; (2) when there are many I/O, it is advantageous to distribute them on several servers. However, each server must have a cache for input data so that it does not compete for the same resource; and (3) GPU-based parallel processing method is most suitable for models such as PRISM with large computation loads.