• Journal of Microbiology
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• v.41 no.1
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• pp.16-21
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• 2003

We have collected eight high-level streptomycin-resistant strains of Pseudomonas marginalis and P. syringae pv. actinidiae which were isolated from kiwifruit orchards in Korea and Japan, The molecular mechanisms of resistance were investigated by the PCR, susceptibility tests, and nucleotide sequence analysis. Of the eight high-level streptomycin-resistant strains, four harbored strA-strB genes, which encode streptomycin-inactivating enzymes. While the three Korean strains of R marginalis did not have plasmid and carried the resistant genes in the chromosomes, the Japanese strain of P. syringae pv. actinidiae had a plasmid containing strA-strB genes. The myomycin susceptibility test demonstrated that the high-level resistance to streptomycin of the remaining four strains is associated with mutations in the rpsL gene. Nucleotide sequence analyses revealed that they contain a single base-pair mutation in codon 43 of their rpsL gene.

• Journal of Veterinary Science
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• v.21 no.3
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• pp.40.1-40.8
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• 2020

The purpose of this study was to investigate the high-level mupirocin resistance (HLMR) in Gram-positive bacteria isolated from companion animals. A total of 931 clinical specimens were collected from diseased pets. The detection of mupirocin-resistant bacteria and plasmid-mediated mupirocin resistance genes were evaluated by antimicrobial susceptibility tests, polymerase chain reactions, and sequencing analysis. Four-hundred and six (43.6%) bacteria were isolated and 17 (4.2%), including 14 staphylococci and 3 Corynebacterium were high-level mupirocin-resistant (MICs, ≥ 1,024 ug/mL) harboring mupA. Six staphylococci of HLMR strains had plasmid-mediated mupA-IS257 flanking regions. The results show that HLMR bacteria could spread in veterinary medicine in the near future.

• International Journal of High-Rise Buildings
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• v.2 no.3
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• pp.271-283
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• 2013

This paper introduces the current status of high-rise building design in Japan, with reference to some recent projects. Firstly, the design approval system and procedures for high-rise buildings and structures in Japan are introduced. Then, performance-based wind-resistant design of a 300 m-high building, Abeno Harukas, is introduced, where building configuration, superstructure systems and various damping devices are sophisticatedly integrated to ensure a higher level of safety and comfort against wind actions. Next, design of a 213 m-high building is introduced with special attention to habitability against the wind-induced horizontal motion. Finally, performance-based wind-resistant design of a 634 m-high tower, Tokyo Sky Tree, is introduced. For this structure, the core column system was adopted to satisfy the strict design requirements due to the severest level of seismic excitations and wind actions.

• Biomedical Science Letters
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• v.16 no.4
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• pp.331-339
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• 2010

This study aims to evaluate the effect of Photodynamic Therapy (PDT) against methicillin-resistant Staphylococcus aureus with high-level mupirocin resistance (Hi-Mup MRSA). To examine the antimicrobial effect of photogem-mediated PDT against Hi-Mup MRSA, CFU quantifications, bacteria cell viability tests, and disk diffusion antimicrobial susceptibility tests were evaluated. In addition, one of PDT mechanisms was investigated by accumulating photogem ($10\;{\mu}g/ml$) in Hi-Mup MRSA. Photogem-mediated PDT properly inhibited the colony formation of Hi-Mup MRSA. Viable bacteria decreased greatly after a PDT application with photogem $10\;{\mu}g/ml$ at energy density $15\;J/cm^2$. The diameter of the inhibition zone around susceptible disks increased after PDT. In addition, we confirmed the accumulation of photogem in bacteria through fluorescent images. These results demonstrated that excellent photosensitization of Hi-Mup MRSA can be achieved using photogem with 630 nm LED irradiation. Thus, PDT may make survival Hi-Mup MRSA inactive.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.638-643
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• 2003

Raw milk samples, and cow and chicken intestines were tested to isolate vancomycin-resistant, gram-positive bacteria. From these samples, we isolated seven vancomycin-resistant Streptococcus equinus, two vancomycin-resistant viridans Streptococcus and two vancomycin-resistant Enterococcus faecium. The MICs of several antibiotics, including vancomycin, against these strains were tested. Seven isolates of S. equinus showed high level resistance to vancomycin and teicoplanin (＞100 $\mu$ g/mL). The cell wall thickness of these strains was compared with that of the sensitive strain by TEM and no differences were obserbed between these strains. We compared the strains of vancomycin-resistant Streptococcus equinus using PCR with Microbial Uniprimer Kit. We concluded that it is necessary to combine other methods in order to cluster and identify all isolates of S. equinus.

• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.389-398
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• 2020

The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is increasing globally, resulting in high mortality rates. Although CRE is a relatively recent problem in Korea (the first case was not diagnosed until 2010), it is responsible for serious morbidities at an alarming rate. In this study, we carried out a molecular genetic analysis to determine the incidence of CRE and carbapenemase-producing Enterobacteriaceae (CPE) at a general hospital in Korea between August 2017 and August 2019. Forty strains of CPE were isolated from various clinical specimens and analyzed via antimicrobial susceptibility testing, polymerase chain reaction to detect β-lactamase genes, deoxyribonucleic acid sequencing, multilocus sequence typing, curing testing, and conjugal transfer of plasmids. The results demonstrated that all 40 isolates were multidrug-resistant. The fluoroquinolone susceptibility test showed that 75% of the Enterobacteriaceae isolates were resistant to ciprofloxacin, whereas 72.5% were resistant to trimethoprim-sulfamethoxazole. Further, conjugation accounted for 57.5% of all resistant plasmid transfer events, which is 4.3-fold higher than that observed in 2010 by Frost et al. Finally, the high detection rate of transposon Tn4401 was associated with the rapid diffusion and evolution of CPE. Our results highlight the rapid emergence of extensively drugresistant strains in Korea and emphasize the need for employing urgent control measures and protocols at the national level.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.5
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• pp.659-664
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• 2010

The present study was to investigate the effect of the transition from conventional to organic dairy farming on the antimicrobial resistant pattern of pathogens in milk. A farm with tie-stall management, with an average herd size of 20 milking cows, was selected based on the owner' willingness to accept, for at least 6 months, the highly restricted protocol developed in this study. Comparisons of bacterial isolates and antimicrobial susceptibilities before changing to an organic farm system (BEFORE) and for 6 months after (AFTER) operating the experimental organic farm system were performed by Fisher's Exact Chi-square tests. Significant levels were defined at p<0.05. During the AFTER period, average frequency of antibiotic treatment was decreased from more than 3 cases/month to less than 1 case/month during which the antibiotic use was authorized only by the veterinarian. In total, 92 and 70 quarter milk samples from 24 and 18 cows during BEFORE and AFTER, respectively, were included in the study. Overall, isolates ranged from a non-resistant level for cephazolin to a very high resistant level to streptomycin (64.71% to 95.45%). Percentages of antimicrobial resistant isolates during BEFORE were significantly higher than during AFTER for ampicillin (43.48% and 5.88%, respectively) and streptomycin (95.45% and 64.71%, respectively). In conclusion, percentages of antimicrobial resistant isolates were decreased after 6 months of operating as an organic farm system.

• Journal of Microbiology
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• v.38 no.2
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• pp.99-104
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• 2000

Hydrogen peroxide has been used in cleaning the piping of an advanced high-purity water system that supplies ultra-high purity water (UHPW) for 16 megabyte DRAM semiconductor manufacturing. The level of hydrogen peroxide-resistant bacteria in UHPW water was monitored prior to and after disinfecting the piping with hydrogen peroxide. Most of the bacteria isolated after hydrogen peroxide disinfection were highly resistant to hydrogen peroxide. However, the percentage of resistant bacteria decreased with time. The hydrogen peroxide-resistant bacteria were identified as Micrococcus luteus, Bacillus cereus, Alcaligenes latus, Xanthomonas sp. and Flavobacterium indologenes. The susceptibility of the bacteria to hydrogen peroxide was tested as either planktonic cells or attached cells on glass. Attached bacteria as the biofilm on glass exhibited increased hydrogen peroxide resistnace, with the resistance increasing with respect to the age of the biofilm regrowth on piping after hydrogen peroxide treatment. In order to optimize the cleaning strategy for piping of the high-purity water system, the disinfecting effect of hydrogen preoxide and peracetic acid on the bacteria was evaluated. The combined use of hydrogen peroxide and peracetic acid was very effective in killing attached bacteria as well as planktonic bacteria.

• Korean journal of applied entomology
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• v.28 no.3
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• pp.146-153
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• 1989

These studies were conducted to investigate development of chemical resistance in two-spotted spider mite (Tetranychus urticae Koch) trough single selection for a given period of time with five acaricides including carbophenothion and ethion of organo-phosphate compound, dicofol of organo-chlorine compound, cyhexatin of organo-tin compound, biphenthrin of synthetic pyrethroid compound; and to examine cross-resistance among the acaricides to the selected populations. The development of chemical resistance of two-spotted spider mite was greatly varied under single selection of the each five acaricides. The carbophenothion- and the ethion-populations at the 22nd and the 24th selected generations showed 156- and 64.1-fold resistant levels, respectively, as compared with the susceptible population. However, the dicofol population at the 28th selected generation exhibited 39.7-fold resistant level, and the biphenthrin population at the 24th selected generation revealed 25.2-fold resistant level, while the cyhexatin population at the 20th selected generation showed 13-fold resistant level. The carbophenothion-selected population showed high cross-resistance to ethion, and low cross-resistance to dicofol and biphenthrin. The ethion-selected population revealed also high cross-resistance to carbophenothion. The dicofol-or the biphenthrin-selected populations, however, exhibited moderate cross-resistance to carbophenothion and ethion. Meantime, the cyhexatin-selected population showed high cross-resistance to ethion and carbophenothion.

• Tuberculosis and Respiratory Diseases
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• v.82 no.2
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• pp.143-150
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• 2019

Background: The purpose of this study was to analyze the relationship between the gene mutation patterns by the GenoType MTBDRplus (MTBDRplus) assay and the phenotypic drug susceptibility test (pDST) results of isoniazid (INH) and prothionamide (Pto). Methods: A total of 206 patients whose MTBDRplus assay results revealed katG or inhA mutations were enrolled in the study. The pDST results were compared to mutation patterns on the MTBDRplus assay. Results: The katG and inhA mutations were identified in 68.0% and 35.0% of patients, respectively. Among the 134 isolated katG mutations, three (2.2%), 127 (94.8%) and 11 (8.2%) were phenotypically resistant to low-level INH, high-level INH, and Pto, respectively. Among the 66 isolated inhA mutations, 34 (51.5%), 18 (27.3%) and 21 (31.8%) were phenotypically resistant to low-level INH, high-level INH, and Pto, respectively. Of the 34 phenotypic Pto resistant isolates, 21 (61.8%), 11 (32.4%), and two (5.9%) had inhA, katG, and both gene mutations. Conclusion: It is noted that Pto may still be selected as one of the appropriate multidrug-resistant tuberculosis regimen, although inhA mutation is detected by the MTBDRplus assay until pDST confirms a Pto resistance. The reporting of detailed mutation patterns of the MTBDRplus assay may be important for clinical practice, rather than simply presenting resistance or susceptibility test results.