• YAKHAK HOEJI
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• v.53 no.4
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• pp.194-200
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• 2009

Community-acquired antimicrobial resistant bacteria are an emerging problem whole world-wide. Generally, Hands are main mediator of pathogen transmission as compared with other body parts. So, the purpose of this research was to investigate the microbiological quality and antimicrobial susceptibilities of samples which were collected from the door knob and surface in public- and home-facilities, and also hand. Of total 191 samples, 71 samples (37%) were shown to be of high-level total bacterial count (>$10^8\;CFU/cm^2$). And presence of Staphylococcus and Enteric bacilli was observed in 61 samples (32%) and 76 samples (40%), respectively. Antimicrobial susceptibilities of staphylococcal isolates from the samples were tested for six different antimicrobial agents, which are in wide spread clinical use in Korea, as well as four new antimicrobials, daptomycin, linezolid, quinupristin/dalfopristin and tigecycline. Among staphylococcal isolates, antimicrobial resistance were observed in oxacillin (n=6), mupirocin (n=7), vancomycin (n=1), quinupristin/dalfopristin (n=2) and gentamicin (n=5). Fortunately, all the isolates were susceptible to new antimicrobial such as daptomycin, linezolid and tigecycline. Furthermore 4 Enterococcus faecalis were isolated from four hand samples, and all these isolates exhibited multidrug resistance to four different antimicrobial (oxacillin, quinupristin/dalfopristin, mupirocin, gentamicin). Also, 5 Escherichia coli were isolated from surface in home (n=3), door knob in public facilities (n=1) and hand (n=1). Escherichia coli isolated from hand was high-level resistant to tigecycline ($128{\mu}g$/ml) and gentamicin ($64{\mu}g$/ml).

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.57-66
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• 1987

Mutants of E. coli which showed increased sensitivity to MMS(methylmethane sulfonate)were isolated by MNNG mutagenesis and characterized by enzymatic assay, survival of simple alkylating agents and host-cell reactivation. E.coli mutant, 5-62, which showed absolute deficiency in 3-methyladenine DNA glycosylase II activity and had low capability of reactivating MMS-treated phage charon 35 was very sensitive to MMS and MNNG. NNS gene which confered resistance to the lethal effects of MMS was cloned in 5-62 strain. 5-62 mutants carrying recombinant plasmid, pMRG 1, which acquired resistance to the lethal effects of MMS had normal sensitivity to MNNG. Resistance to MMS was somewhat increased after they were treated with 0.5.$\mu$g MNNG/ml for 2 hours at $37^{\circ}C$. Although recombinant plasmid, pMRG 1, did not complement alk A mutation in 5-62 and ada mutation in 1-27 mutnat, mutnats transformed with this plasmid showed more capability of reactivating MMS treated phage than mutants.

• Journal of Sensor Science and Technology
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• v.25 no.1
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• pp.1-7
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• 2016

Bioelectrical impedance (BI) at popliteal regions was measured using a bioelectrical impedance measurement system (BIMS), which employs the multi-frequency and the two-electrode method. Experiments were performed as follows. First, a constant AC current of $800{\mu}A$ was applied to the popliteal regions (left and right) and the BI was measured at eight different frequencies from 10 to 500 kHz. When the applied frequency greater than 50 kHz was applied to human's popliteal regions, the BI was decreased significantly. Logarithmic plot of impedance vs. frequency indicated two different mechanisms in the impedance phenomena before and after 50 kHz. Second, the relationship between resistance and reactance was obtained with respect to the applied frequency using BI (resistance and reactance) acquired from the popliteal regions. The phase angle (PA) was found to be strongly dependent on frequency. At 50 kHz, the PA at the right popliteal region was $7.8^{\circ}$ slightly larger than $7.6^{\circ}$ at the left popliteal region. Third, BI values of extracellular fluid (ECF) and intracellular fluid (ICF) were calculated using BIMS. At 10 kHz, the BI values of ECF at the left and right popliteal regions were $1664.14{\Omega}$ and $1614.08{\Omega}$, respectively. The BI values of ECF and ICF decreased sharply in the frequency range of 10 to 50 kHz, and gradually decreased up to 500 kHz. Logarithmic plot of BI vs. frequency shows that the BI of ICF decreased noticeably at high frequency above 300 kHz because of a large decrease in the capacitance of the cell membrane.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.316-319
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• 2017

The antibiotic resistant genes (ARG) and mobile genetic elements (MGE) were investigated with the effluent of waste-water treatment plant (WWTP), and river waters of upstream and downstream in order to elucidate the effect of effluent on antibiotic resistance in a natural river. Total numbers of 134~183 of ARG and MGE were detected and the abundance of ARG and MGE was 0.063~0.422 copies per one of 16S rRNA gene in three water samples. Effluent sample contained the highest amount of the total number and abundance of ARG and MGE whereas total viable cells were observed in the lowest amount among the three samples. This indicated that the genes were originated from cells died during the wastewater treatment process. In addition, the co-relationship of abundance between ARG and MGE suggested that acquired resistance was a prevalent mechanism among the antibiotic-resistant bacteria existing in WWTP.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.2
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• pp.58-65
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• 2021

In order to study the self-propulsion test and analysis techniques for the submerged body in Large Cavitation Tunnel (LCT). DARPA Suboff, a submarine model publicly available was manufactured. The resistance results of DARPA Suboff was acquired from the LCT tests and compared with those of DTRC. After the wall blockage correction, the resistance results of LCT were in good agreement with those of DTRC. On the basis of the resistance results of LCT, the self-propulsion tests were conducted in LCT. The test objective was to get the full-scale propeller operating conditions for the propeller cavitation and noise tests. The test results of DARPA Suboff were analyzed in a way similar to the analysis techniques of those of the Towing Tank (TT). Another submerged body, for which self-propulsion tests were conducted in TT, was selected for results verification. The results of LCT were in good agreement with those of TT. On the basis of the present study, it is thought that the operating conditions for the full-scale submerged body can be drawn through LCT tests.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.143-143
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• 2022

Plant defense systems against pathogens have been studied extensively and are currently a hot topic in plant science. Using a reverse genetics technique, this study looked into the involvement of the NO-downregulated NAD(P)-binding Rossmann-fold superfamily gene in plant growth and defense in Arabidopsis thaliana. For this purpose, the knockout and overexpressing plant of the candidate gene along with the relevant controls were exposed to control, oxidative and nitro-oxidative stresses. The results showed that candidate gene negatively regulates plants' root and shoot lengths. To investigate the role of the candidate gene in plant basal defense, R-gene-mediated resistance and systemic acquired resistance (SAR) plants were challenged with virulent or avirulent strains of Pseudomonas syringae pathovar tomato (Psf) DC3000. The results showed that the candidate gene negatively regulates plants' basal defense, R-gene-mediated resistance and SAR. Further characterization via GO analysis associated the candidate gene with metabolic and cellular processes and response to light stimulus, nucleotide binding and cellular location in the cytosol and nucleus. Protein structure analysis indicated the presence of a canonical Oxidoreductase family NAD (P)-binding Rossmann fold domain of 120 amino acids with a total of 121 plant homologs across 35 different plant species in the clad streptophyta. Arabidopsis eFP browser showed its expression in almost all the above-ground parts. Protein analysis indicated C225 and C359 as potential targets for S-Nitrosylation by NO. SMART analysis indicated possible interactions with mevalonate/galactokinase, galacturonic acid kinase, arabinose kinase, putative xylulose kinase, GroES-like zinc-binding alcohol dehydrogenase and various glyceraldehyde-3-phosphate dehydrogenases.

• Tuberculosis and Respiratory Diseases
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• v.52 no.3
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• pp.207-218
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• 2002

Background : Intensive care units (ICUs) are generally considered epicenters of antibiotic resistance and the principal sources of multi-resistant bacteria outbreaks. The antibiotic resistance in newly opened intensive care unit that has no microbial colonization on and around the devices was investigated. Materials and Methods : The authors analyzed the antibiotic resistance patterns for common hospital acquired-pneumonia pathogens in the ICUs(Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter spp.) at the newly opened ICU of Hanyang University Medical Center, Kuri Hospital during 6 years(1995-2000). Results : 1) Regarding Staphylococcus aureus, the resistance rate to methicillin was 15% at 1995, 21% at 1996, 20% at 1997, 23% at 1998, 22% at 1999, 55% at 2000. 2) Regarding Pseudomonas aeruginosa, the resistance rate to $3^{rd}$ cephalosporin was 50% at 1995, 50% at 1996, 78% at 1997, 40% at 1998, 77% at 1999, 39% at 2000. Imipenam was 0% at 1995, 27% at 1996, 65% at 1997, 12% at 1998, 16% at 1999, 12% at 2000. Ciprofloxacin was 0% at 1996, 56% at 1997, 36% at 1998, 57% at 1999, 58% at 2000. Tobramycin was 7% at 1995, 10% at 1996, 67% at 1997, 36% at 1998, 65% at 1999, 12% at 2000. Gentamycin was 14% at 1995, 36% at 1996, 67% at 1997, 36% at 1998, 65% at 1999, 12% at 2000. Amikacin was 14% at 1995, 30% at 1996, 61% at 1997, 16% at 1998, 39% at 1999, 18% at 2000. 3) Regarding Acinetobacter spp., the resistance rate to $3^{rd}$ cephalosporin was 92% at 1996, 89% at 1997, 88% at 1998,84% at 1999, 77% at 2000. Imipenem was 50% at 1996, 48% at 1997, 45% at 1998, 49% at 1999, 50% at 2000. Ciprofloxacin was 0% at 1996, 48% at 1997, 33% at 1998, 27% at 1999, 71% at 2000. Tobramycin was 67% at 1995, 100% at 1996, 89% at 1997, 95% at 1998, 87% at 1999, 77% at 2000. Gentamycin was 67% at 1995, 100% at 1996, 89% at 1997, 95% at 1998, 87% at 1999, 83% at 2000. Amikacin was 33% at 1995, 83% at 1996, 82% at 1997, 88% at 1998, 75% at 1999, 69% at 2000. Conclusion : The S.aureus resistance to methicillin, the Pseudomonas aeruginosa resistance to ciprofloxacin, and the Acinetobacter spp. resistance to ciprofloxacin have rapidly increased during 6 years. There is a need to pay speicial attention when using the the antibiotics for the above pathogens. This data may be useful in antibiotic therapy in newly opened intensive care units.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3315-3322
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• 2015

Staphylococcus aureus is the major causative organism of nasocomial infection being the important pathogen in the clinic. Appearance of staphylococcus aureus resistant to methicillin (MRSA) is becoming a big problem in clinics and dynamics all over the world acquiring antibiotic resistance with virulence factors as its feature differentiated from other pathogenic bacteria fast. This research intended to compare and analyze the correlation of antibiotics resistance between strains with toxin genes and distribution of toxin genes of MRSA 101 strains acquired from clinical specimen in one general hospital (enterotoxin(se), toxic shock syndrome toxin-1(tst), exfoliative toxin(et), Panton Valentine leukocidin(pvl)). seg gene, isolated the most among toxin genes, was detected in 59 strains (58.4%) and more than two toxin genes were detected in 70 strains (69.3%). As a combination possessing toxin genes, it was detected in 19 strains (18.8%) as seb, sec, seg, sei, tst and the second frequent combination was sec, seg, sei shown in 11 strains (10.9%). 19 strains (18.8%) with combinations of toxin genes same with seb, sec, seg, sei, tst had 100% resistance Ampicillin, Benzylpenicillin, Ciprofloxacin, Clindamycin, Gentamicin, Erythromycin, Telithromycin, Tetracycline antibiotics. Strains with many toxin genes showed high correlation of antibiotic resistance. Afterwards, effective therapy and thorough infection management should be preceded not to spread the resistance of MRSA strain.

• Molecules and Cells
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• v.28 no.5
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• pp.431-439
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• 2009

Rice Oryza sativa accelerated cell death and resistance 1 (OsACDR1) encodes a putative Raf-like mitogen-activated protein kinase kinase kinase (MAPKKK). We had previously reported upregulation of the OsACDR1 transcript by a range of environmental stimuli involved in eliciting defense-related pathways. Here we apply biochemical, gain and loss-of-function approaches to characterize OsACDR1 function in rice. The OsACDR1 protein showed autophosphorylation and possessed kinase activity. Rice plants overexpressing OsACDR1 exhibited spontaneous hypersensitive response (HR)-like lesions on leaves, upregulation of defense-related marker genes and accumulation of phenolic compounds and secondary metabolites (phytoalexins). These transgenic plants also acquired enhanced resistance to a fungal pathogen (Magnaporthe grisea) and showed inhibition of appressorial penetration on the leaf surface. In contrast, loss-of-function and RNA silenced OsACDR1 rice mutant plants showed downregulation of defense-related marker genes expressions and susceptibility to M. grisea. Furthermore, transient expression of an OsACDR1:GFP fusion protein in rice protoplast and onion epidermal cells revealed its localization to the nucleus. These results indicate that OsACDR1 plays an important role in the positive regulation of disease resistance in rice.

• Ecology and Resilient Infrastructure
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• v.8 no.4
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• pp.212-222
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• 2021

In this study, the flow resistance coefficient was calculated considering the physical properties and distribution characteristics of floodplain vegetation, and the effect of floodplain vegetation distribution on flow characteristics was analyzed by reflecting it in a two-dimensional numerical simulation. The three-dimensional point clouds of vegetation acquired using ground lidar were analyzed to apply floodplain vegetation's physical properties to the existing formula for vegetation flow resistance calculation. The floodplain vegetation distribution in the modeling was divided into locally distributed and fully distributed conditions in the floodplain. As a result of the simulation of the study site, the flow resistance coefficient of floodplain vegetation was found to have a value of about five times or more compared to the flow resistance coefficient of the main channel bed when the design flood occurs based on Manning's n coefficient. Also, it affected the hydraulic characteristics in the main channel and floodplain.