• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1039-1046
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• 2005

The salt resistance of antibacterial activity and synergistic effect with clinically used antibiotic agents are critical factors in developing effective peptide antibiotic drugs. For this reason, we investigated the resistance of antibacterial activity to antagonism induced by NaCl and $MgCl_2$ and the synergistic effect of P20 with cefotaxime. P20 is a 20-residue synthetic peptide derived from a cecropin A (CA)-melittin(ME) hybrid peptide. In this study, P20 was found to have potent antibacterial activity against clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) strains without hemolytic activity against human erythrocytes. The combination study revealed that P20 in combination with cefotaxime showed synergistic antibacterial activity in an energy-dependent manner. We also confirmed the synergism between P20 and cefotaxime by fluorescence-activated flow cytometric analysis by staining bacterial cells with propidium iodide (PI) and bis-(1,3-dibutylbarbituric acid) trimethine oxonol (BOX). This study suggests that P20 may be useful as a therapeutic antibiotic peptide with synergistic effect in combination with conventional antibiotic agents.

• 대한수의학회지
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• 제39권2호
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• pp.383-389
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• 1999

A randomized experimental study was done to evaluate short course therapeutic efficacies of two types of mupirocin ointment (Bactroban Nasal and Bactroban) in the elimination of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization (16 dogs) and wound infection (3 dogs or 18 wound sites) in dogs. In each model, dogs being assigned to TR-1 treatment group was given ointment twice a day for two consecutive days, and those that assigned to TR-2 treatment group was given the same dose for three days. Neither TR-1 nor TR-2 regimen was effective to clear nasal carriage completely with a clearing rate of 62.5% and 87.5%, respectively. Whereas, for 2 days at least twice daily application of mupirocin for wound infection was quite enough to eliminate MRSA, with a clearing rate of 83.3~100% by 4 weeks follow-up. No apparent side effects were observed in each model, and in no case was it necessary to discontinue the treatment. Further controlled studies on the elimination of nasal colonization are required to establish cost-effective and efficient regimen on companion animals.

• 생명과학회지
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• 제20권4호
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• pp.589-596
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• 2010

병원 내 감염의 주된 원인균으로 알려진 황색포도상구균(S. aureus)과 항생제 내성 황색포도상구균(PRSA, MRSA)에 대해 항균활성이 우수한 천연 항균성 물질을 검색하기 위해 적송잎을 대상으로 열수-헥산(HWH), 열수-에탄올(HWE), 헥산, 에탄올 및 열수 등으로 획득된 추출물들로 항균활성을 조사하였다. 헥산, 에탄올, 열수-헥산, 열수-에탄올 추출물들은 그람양성 대표세균인 고초균(B. subtilis), 황색포도상구균 표준균주, 항생제 내성균주인 PRSA 및 MRSA에 대해서 항균활성을 나타내었으며, 특히 MRSA (ATCC 33591) 균주에 대해 다른 균주들 보다 높은 항균활성을 나타냈다. 열수 추출물은 황색포도상구균 표준균주 및 MRSA에서만 항균활성을 나타냈지만, 항균활성은 가장 높아 50 mg/ml의 농도에서 33 mm의 생육저해환을 나타냈다. 각 균주들에 대한 생장의 최소저해 농도(MIC)는 HWH 및 HWE 추출물이 모두 0.05 mg/ml의 농도로 가장 낮았고, 열수추출물이 0.5 mg/ml의 농도였으며, 에탄올 추출물은 5 mg/ml의 가장 높은 농도를 나타냈다. 모든 추출물들은 $121^{\circ}C$에서 20분간의 열처리 후에도 항균활성이 유지되었으므로 열에 대해 안정한 물질임을 알 수 있었다. 본 연구결과로 식품산업에서 솔잎 추출물을 천연 항균제로 사용할 수 있을 것으로 기대할 수 있다.

• 생명과학회지
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• 제11권1호
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• pp.24-34
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• 2001

Methicillin Resistant Staphylococcus aureus (MRSA) was obtained from the clinical specimens at Pusan national university Hospital, Pusan, Korea. The sensitivities against various antibiotics were examined by using disc diffusion test and associated genes such as mecA, mecR1, mecI and femA were detected by polymerase chain reaction. Among Seventy-nine strains of MRSA, 38 strains(48.1%)were sensitive to streptomycin and 32 strains(40.5%) to cefoperazone, while one strain(1.3%) were resistant to vancomycin. In considering the result of this study, 7 strains showed resistance to 9 kinds of different antibiotics, 12 strains were to 8 kinds, 24 strains were to 7,25 strains were to 6, 9 strains were to 5, and 2 strains were to 4 antibiotics. Among 79 strains of MRSA, 67 strains were coagulase positive and 12 were coagulase negative. In the detection of MRSA associated genes by PCR method, mecA, mecR1, mecI, and femA genes were detected in 30 strains(44.8%), 28 strains(41.8%), 23 strains(34.3%) and 15 strains(22.4%), respectively. MecA type that is without femA were found in 21 strains(31.3%), femA type that is without regulator genes were shown in 4 strains(6.0%), while mecA-mecR1-mecI type with regulator genes were shown more to be 17 strains(25.4%). There was little statistical significance between multidrug resistance and MRSA associated genes. Considering these result, it is necessary to include moecular biological studies of related genes to the study drug resistance.

• 복식문화연구
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• 제11권3호
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• pp.441-446
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• 2003

Water-insoluble chitosan with molecular weight of 2,000,000, 500,000, 80,000, and 40,000 and more than 90% of degree of deacetylation were used to test antibacterial activity of chitosan against a pathogenic bacteria, methicillin resistant Staphylococcus aureus(MRSA), which is being issued in the world. As experimental method, Agar plate Smear Method and Agar plate Contact Method were used. The moleculur weight of chitosan didn't exert significant influences on its antibacterial activity against MRSA but chitosan having molecular weight 40,000, 80,000 and 150,000 showed the excellent antibacterial activity. The antibacterial efHciency was excellent in applying it after chitosan was dissolved in acetic acid solution, while the antibacterial efficiency was not expressed nearly in case of applying after chitosan was dissolved in neutral water. Therefore, it is considered that chitosan can show the antibacterial efficiency only if a positive ion status of -NH₃/sup +/ is maintained. MIC of chitosan/acetic acid solution and cotton fabrics finished with chitosan/acetic acid solution showed in concentration of 0.05%.

• 한국의류산업학회지
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• 제4권6호
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• pp.557-563
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• 2002

Water-soluble chitosan and water-insoluble chitosan with molecular weight of 2,000,000, 500,000, 80,000, and 40,000 with more than 90%of degree of deacetylation were produced to test antibacterial activity of chitosan against a pathogenic bacteria, Methicillin Resistant Staphylococcus aureus(MRSA). the AATCC Test Method 100and Modified AATCC Test Method 100 were used to evaluate the antibacterial activity of chitosan. Antibacterial activity of chitosan/acetic acid solution was the same when they were tested by two different methods, but those of polyester fabrics treated with chitosan/acetic acid solution were different in different antibacterial test. So several problems were found in the experimental methods. The AATCC Test Method 100 seems that excessive nutrition exists in inoculum solution by quantitative analysis on the basis the result of antibacterial activity on chitosan/acetic acid solution and amount of chitosan attached to the surface of treated fabrics.

• 대한한방내과학회지
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• 제23권2호
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• pp.298-305
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• 2002

These cases were performed on the bases of clinical consideration about patients who had Methicillin-Resistant Staphylococcus aureus(MRSA) infection. One patient was a 67-years-old women who had sequela of inter cranial hemorrhage & inter ventricular hemorrhage, hypertention, urinary tract infection and pneumonia. Clinical symptoms were intermittent fever, sputum, Lt. side hemiparesis and dysphagia. She was chronic, repeated infection state. It could be regarded as "unpreparedness of the spirit which animates and controls the universe; 正氣虛", the oriental term which indicates a condition of chronic disease or general weakness. According to the oriental medicine principle, oriental medicine was taken such as Wunggunza-tang(六君子湯) and the patient had taken a turn for the better. After 3 months, MRSA infection diappeared. The other patient was a 43-years-old women who had Both brain stem infarction, Lt. cerebellar infarction, hypercholesterolemia, urinary tract infection and pneumonia, Clinical symptoms were quadriplegia, dysphagia(levin tube insert state), aphasia, respiration disorder(tracheostomy cannular keep state) and sputum. She was chronic, repeated infection state. It could be regarded as "unpreparedness of spleen energy, unpreparedness of both energy and blood; 脾氣虛, 氣血兩虛", the oriental term which indicates a condition of chronic disease or immunodeficiency. According to the oriental medicine principle, oriental medicine was taken such as Bojungyggi-tang(補中益氣湯), Palmul-tang(八物湯) and the patient had taken a turn for the better. After I month, MRSA was turned into Escherichia coli.

• 보건의료산업학회지
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• 제8권4호
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• pp.163-173
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• 2014

This study was performed to investigate the current status of isolation precautions of multidrug resistant organisms(MDROs) in general hospitals with more than 200bed. The questionnaires were mailed from 3rd, April 2013 to 30th, April 2013. Methicillin resistant Staphylococcus aureus:(MRSA), vancomycin resistant Staphylococcus aureus:(VRSA), vancomycin resistant Enterococcus(VRE), multidrug-resistant Acinetobacter baumannii, carbapenem-resistant Enterobacteriaceae multidrug-resistant Pseudomonas aeruginosa were enrolled. MRSA(100.0%) and VRE(98.7%) were isolated respectively. VRE(97.3%) and MRSA(64.0%) were regulated strictly respectively. VRE(91.5%) and VRSA(50.7%) were isolated in a single room respectively. Hospital being located in Seoul(p<0.001), and beds(${\geq}600$)(p=0.008) were different significantly. The isolation space limitation(71.1%) was the highest difficulty. The development of refunding the costs of the extra supplies and other hygienic materials for infection control was discovered as the most urgent strategy.

• 성인간호학회지
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• 제27권3호
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• pp.325-336
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• 2015

Purpose: This study was conducted to identify factors influencing compliance of multidrug-resistant organism infection control in intensive care units (ICU) nurses. Methods: Data were collected from 254 ICU nurses who were working at 6 general and advanced general hospitals in D city and G Province. Results: 77.2% and 84.4% of the subjects correctly answered to questions about Methicillin-Resistant Staphylococcus Aureus (MRSA) and Vancomycin-Resistant Enterococcus (VRE), respectively. The scores of MRSA infection control compliance and VRE infection control compliance were 3.41 and 3.43, respectively. The factors influencing MRSA infection control compliance were empowerment, environmental safety recognition, and education satisfaction, which explained 30% of MRSA infection control compliance. The factors significantly related to VRE infection control compliance were empowerment, hospital types, environmental safety recognition, number of education sessions, and neonatal ICU, which explained 37% of VRE infection control compliance. Conclusion: It is necessary to develop efficient educational programs for infection control including educational contents to improve empowerment and environmental safety recognition of nurses. Furthermore, administrative support for those infection control programs is also necessary.

• Journal of Veterinary Science
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• 제25권1호
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• pp.12.1-12.10
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• 2024

Background: Staphylococcus aureus and S. pseudintermedius are the major etiological agents of staphylococcal infections in humans, livestock, and companion animals. The misuse of antimicrobial drugs has led to the emergence of antimicrobial-resistant Staphylococcus spp., including methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. pseudintermedius (MRSP). One novel therapeutic approach against MRSA and MRSP is a peptide nucleic acid (PNA) that can bind to the target nucleotide strands and block expression. Previously, two PNAs conjugated with cell-penetrating peptides (P-PNAs), antisense PNA (ASP)-cmk and ASP-deoD, targeting two essential genes in S. aureus, were constructed, and their antibacterial activities were analyzed. Objectives: This study analyzed the combined antibacterial effects of P-PNAs on S. aureus and S. pseudintermedius clinical isolates. Methods: S. aureus ATCC 29740 cells were treated simultaneously with serially diluted ASP-cmk and ASP-deoD, and the minimal inhibitory concentrations (MICs) were measured. The combined P-PNA mixture was then treated with S. aureus and S. pseudintermedius veterinary isolates at the determined MIC, and the antibacterial effect was examined. Results: The combined treatment of two P-PNAs showed higher antibacterial activity than the individual treatments. The MICs of two individual P-PNAs were 20 and 25 µM, whereas that of the combined treatment was 10 µM. The application of a combined treatment to clinical Staphylococcus spp. revealed S. aureus isolates to be resistant to P-PNAs and S. pseudintermedius isolates to be susceptible. Conclusions: These observations highlight the complexity of designing ASPs with high efficacy for potential applications in treating staphylococcal infections in humans and animals.