• Journal of Microbiology
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• 제44권3호
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• pp.336-343
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• 2006

We compared the antimicrobial resistance and clonal relationships among the community-acquired (CA) and hospital-acquired (HA) methicillin-resistant Staphylococcus aureus (MRSA) strains that were isolated from blood cultures in a university hospital over a 4-year period. A total of 131 MRSA isolates, including 28 CA-MRSA and 103 HA-MRSA strains, were identified; antimicrobial susceptibility testing indicated that the CA-MRSA isolates were more susceptible to erythromycin (21 % vs 6% ; P=0.02), clindamycin (46% vs 12%; P<0.01), ciprofloxacin (43% vs 11%; P<0.01), and gentamicin (43% vs 6%; P<0.01) than were the HA-MRSA isolates. Pulsed-field gel electrophoresis (PFGE) typing and antimicrobial resistance profiles separated the 20 CA-MRSA isolates into 14 and 10 different patterns, respectively, and the 53 HA-MRSA isolates were separated into 24 and 7 different patterns, respectively. Twenty-one (40%) of the 53 HA-MRSA isolates belonged to two predominant PFGE types, and most of them showed multi-drug resistant patterns. Four (20%) of the 20 CA-MRSA and 10 (19%) of the 53 HA-MRSA isolates fell into two common PFGE patterns, and each of them showed the same multi-drug resistant pattern. This study suggests that, although the CA-MRSA blood isolates showed diverse PFGE and antimicrobial resistance patterns, some of these isolates may have originated from the HA-MRSA strains.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.449-457
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• 2021

The aim of the present study was to survey the frequency of inducible and constitutive phenotypes and inducible cross-resistant genes by regulating the methylation of 23S rRNA (ermA, ermB, and ermC) and macrolide efflux-related msrA gene in Staphylococcus aureus and S. epidermidis strains. A total of 172 bacterial isolates (identified based on standard tests), were examined in this study. Antibiotic susceptibility was determined by the disk diffusion method, and all isolates were evaluated with respect to inducible and constitutive phenotypes. The presence of ermA, ermB, ermC, and msrA genes was investigated by a PCR assay. The constitutive resistance phenotypes showed a higher distribution among the isolates. R phenotype was detected more among S. epidermidis isolates (46.25%). ermB, ermC, and msrA genes were detected more in methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. epidermidis (MRSE) isolates that had R and HD phenotypes (>77% strains). The ermA gene had the lowest frequency among MRSA, MRSE, MSSA, and MSSE strains (<14% isolates). Distribution of inducible resistance genes in MRSA and MRSE strains, and possibly other species, leads to increased constitutive resistance to erythromycin, clindamycin, and other similar antibiotics. Therefore, it can be challenging to treat infections caused by these resistant strains.

• Journal of Korean Biological Nursing Science
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• 제10권2호
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• pp.147-153
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• 2008

Purpose: Methicillin Resistant Staphylococcus aureus (MRSA) has become a major clinical problem and one of the major nosocomial pathogen worldwide. The aim of the study was to investigate the epidemiological characteristics of genotypes of MRSA isolated in the A-hospital ICU. Methods: In the period between December 2007 and May 2008, MRSA was isolated from ICU patients and its surrounding environment. Polymerase Chain Reaction (PCR) was conducted for the detection of MRSA gene. The incidence of MRSA in the clinical isolates of Staphylococcus aureus was examined by using a multiplex PCR. The spa gene of Staphylococcus aureus encodes protein A and is used for typing of MRSA. We used sequence typing of the spa gene repeat region to study the epidemiology of MRSA at a hospital. Results: Two different genotypes of MRSA were identified with 90 isolated from the patients and its surrounding environments in the ICU. Conclusion: This study may contribute to the development of effective strategies for preventing nosocomial infections. Genotyping may have more general application for the study of MRSA epidemic outbreak in hospital and community infection.

• Clinical and Experimental Pediatrics
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• 제64권8호
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• pp.415-421
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• 2021

Background: Antibiotic resistance is associated with longer hospitalizations, higher treatment costs, and increased morbidity and mortality rates. Purpose: This study aimed to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Iranian children. Methods: International databases, including Web of Science, PubMed, Embase, and Scopus, and Iranian databases, including Scientific Information Database (www.sid.ir), Magiran, and Iranian Database for Medical Literature (idml.research.ac.ir), were systematically searched for articles published between January 2000 and August 2019. Sources of heterogeneity were determined using subgroup analysis and meta-regression. Results: Overall, 343 studies were identified; of them, 20 were included in the meta-analysis to estimate the pooled prevalence. The pooled prevalence of MRSA was 42% (95% confidence interval [CI], 29-55) among culture-positive cases of S. aureus, 51% (95% CI, 39-62) in hospitalized children, and 14% (95% CI, 0.05-27) in healthy children. Conclusion: The overall pooled prevalence of MRSA in children was 42%. Appropriate infection control measures and effective antibiotic therapy are needed.

• 약학회지
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• 제51권4호
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• pp.253-258
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• 2007

Bombycis corpus, a batryticated silkworm and white-stiff silkworm, is an oriental drug consisting of the dried larva of silkworm, dead and stiffened due to the infection of Beauveria. An peptidyl antimicrobial molecule was purified from B. corpus by reverse phase-column chromatography and HPLC. Its molecular weight was determined to be 2295.45 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Its antimicrobial activity was diminished by trypsin digestion. It exhibited a broad antimicrobial spectrum against not only Gram-negative, but also Gram- positive bacteria. Furthermore, it was found to have an antimicrobial activity against vancomycin-resistant enterococci (VRE), methicillin-resistant S. arureus (MRSA), and vancomycin-intermediate resistant S. arureus (VISA). It may be a useful molecule for a new antibiotic development, especially against antibiotic resistant microbe. This substance may play a role in the defense system of this animal against Beauveria bassiana. This is the first report of a peptidyl antimicrobial substance from B. corpus.

• 대한족부족관절학회지
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• 제13권2호
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• pp.146-149
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• 2009

Purpose: Foot infections are common complications in patients with diabetes. The patients are usually immune-compromised; therefore the pathogens could be resistant to narrow spectrum antibiotics. Those drugs, however, are categorized as specially managed antibiotics, and access are difficult without confirming of the pathogens. Our aim was to analyze the common pathogens in diabetic foot infection and figure out the proper antibiotics. Materials and Methods: We studied 68 patients treated with diabetic foot infection. The pathogens which caused the infection and their sensitivity to initial antibiotics were analyzed. We also investigated the change of the antibiotics after the confirming of the culture result and average time to get the result. Results: Among the 68 patients, 56 (82%) received cephalosporin and beta-lactam antibiotics. Only 12 (18%) who were confirmed the drug resistant pathogens from previous culture, were treated with broad spectrum antibiotics such as vancomycin and tazoperan. Average culture study time was 6 days. Methicillin-resistant staphylococcus aureus (MRSA) was cultured in 19 patients (28%), Methicillin-resistant coagulase negative staphylococcus (MRCNS) in 11 patietns (17%), pseudomonas in 11 patients (17%). Total 44 (65%) including 3 of other antibiotics resistant pathogen needed broad spectrum antibiotics. Thirty two patients (47%) were resistant to initial antibiotics.irt follow up culture, 2 MRSA and 2 MRCNS were found. The antibiotics resistant pathogens were confirmed in 48 (71%) patients at last. Conclusion: Diabetic patients with foot infection need proper antibiotics from initial treatment. The proper broad spectrum antibiotics should assigned to the patients from the first time without the confirming of the culture results.

• 미생물학회지
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• 제41권3호
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• pp.183-187
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• 2005

본 연구는 PC방의 세균 오염 실태를 조사하기 위한 목적으로 2004년 7월${\~}$12월까지 서울시내에 있는 PC방(Internet Cafe)들 중에서 34곳을 표본으로 선정하여 연구를 수행하였다. 총 세균수를 측정한 결과, 키보드에서는 $9.0{\times}10^4$ CFU/ml, 마우스에서는 $2{\times}10$ CFU/ml, 그리고 화장실 손잡이에서는 $5{\times}10^3$ CFU/ml의 세균이 검출되었다. 이는 화장실 손잡이보다 키보드와 마우스에서 세균에 대한 오염정도가 더 심한 것을 의미한다. PC방에서 항생제에 대한 내성을 지닌 7개의 균주를 분리해 내었는데, 2개의 균주는 methicillin과 erythromycin에 대한 내성을 나타내었고, 5개의 균주는 gentamicin, ampicllin, cefotaxim, chloramphenicol에 대해서 내성을 나타내었다. 이들 균주들을 동정한 결과, 2 균주는 Staphylococcus aureus로 동정되었고, 4 균주는 Actinobacillus ureae로 동정되었으며. 나머지 1개의 균주는 Pasteurella multocida로 동정되었다. Pasteurella multocida와 Actinobacillus ureae는 잠재적인 병원균으로 이전에 Pasteurella ureae로 알려졌던 Actinobacillus ureae는 인간의 상부 호흡기에 드물게 공생하는 것으로 알려졌으며, Pasteurella multocida는 많은 가축의 비인두강 안에 존재하는 평범한 정상 균총을 구성하는 세균인 것으로 알려졌다. 항생제 내성에 대한 연구 결과 Staphylococcus aureus는 erythromycin과 methicillin의 혼합제에 대해서 $100\;{\mu}g/ml$ 이상의 높은 항생제 내성을 나타내었고, Pasteurella multocida와 Actinobacillus ureae는 gentamicin, ampicillin 에 대하여 $100\;{\mu}g/ml$ 이상의 높은 항생제 내성이 있음을 알 수 있었다.

• 대한의생명과학회지
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• 제6권3호
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• pp.201-208
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• 2000

Vancomycin은 세포벽의 합성을 억제하여 세균에 대한 항균효과를 나타내는 glycopeptide 계 항생물질로서 그람양성세균으로 인한 감염치료에 광범위하게 사용되며, 특히 methicillin 내성 포도상구균의 선택적 치료제로 쓰이고 있다. 그러나 최근 임상검체에서도 중등도의 내성을 가지는 포도상구균 (Mu50: MIC 8 $\mu\textrm{g}$/ml)이 나타나기 시작하였고 여러 가지 여건상 국내에서도 내성균주가 분리될 가능성이 높다고 사료되어 임상검체 중 methcillin 내성 포도상구균을 대상으로 vancomycin 감수성 및 내성빈도 조사를 실시하고 이에 따른 내성기전을 알아보고자 하였다. 본 실험 결과 107주 (株)의 methicillin 내성균주 중 23.3%가 vancomycin에 대하여 내성을 보였으며 vancomycin 내성을 나타내는 표준균주인 Mu50과 Mu3의 중간 정도의 내성빈도를 보였다. 중합효소 연쇄반응을 통해 장구균의 vancomycin 내성에 관여하는 vanA, vanB, vanC1, vanC2, vanH 특이 유전자는 증폭되지 않았다. SDS-PAGE를 실시하여 81 kDa, 58 kDa, 33 kDa, 28 kDa 등의 주요 단백 분획을 확인하였고, Mu50에서 45 kDa의 특징적인 단백 분획을 관찰하였다. LDH enzyme assay에서는 한 개의 검체가 Mu50과 함께 높은 LDH 활성을 보였다.

• 한국임상수의학회지
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• 제20권3호
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• pp.302-307
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• 2003

인의학에서 메티실린 내성 포도상균주는 병원감염의 주요 원인균으로 보고되고 있지만 소동물에서 이에 대한 연구는 거의 없다. 본 연구에서는 2002년 8월부터 2003년 7월까지 개와 고양이에서 분리된 136개의 포도상구균 분리주 (coagulase 양성 87주, coagulase 음성 49주)에 대하여 항생제 감수성 검사와 이들 분리주에서 메티실린 내성 유전자인 mecA 분포상황을 조사하였다. 136개 분리주중 43주 (31.6％)가 mecA 유전자를 가지고 있었고, 유전자의 분포율은 균주에 따라 상당한 차이를 보였다. 43주의 mecA 양성균주 중 31주 (72.1％)가 oxacillin 내성을 보여 mecA 양성균주가 반드시 oxacillin 내성과 일치하는 것은 아님을 시사하였다. 그러나 mecA 양성균주일수록 oxacillin 내성율이 높았는데 S. intermedius의 71.4％ (p<0.001), coagulase 음성균주의 경우 72.4％가 내성을 보였다 (p<0.001). 분리주의 94주(69％) 적어도 하나 이상의 항생제에 내성을 보였고 특히 31주(22.8％)는 4가지 이상의 항생제에 동시에 내성을 보였다. Penicillin 항생제에 내성율이 71.7％로 가장 높았다. 본 연구는 국내 소동물에서 mcA 양성균주가 존재하며, 이러한 균에 의해 유도된 감염증을 치료할 때 다제내성의 특성 때문에 항생제 선택의 폭이 매우 제한될 수 있음을 시사한다.

• 미생물학회지
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• 제36권3호
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• pp.216-220
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• 2000

부산시 동아대학병원으로 내원한 83명의 환자 가건물로부터 methcillin 내성 Stphylococcus aureus(MRSA) 88 균주를 분리하고 응고 효소의 유형별 분석과 다약제 내성의 상호 관계를 연구하였다. 농(64.7%), 객담(26.2%), 기타 혈액, 장액 및 뇨로부터 균주가 분리되었고 mec A 유전자에 특이적인 primer 5'-AAAATCGATGGTAAAGGTT-GGC-3'와 5'-AGTTCTGCAGTACCGGATTTGC3'를 사용하여 PCR을 한결과 86균주에서 mec 유전자가 확인되었다. 응고효소형은 제 III형이 50%m IV형이 12.5%, III형이 6.8%, I, VII, VIII형이 4.5%로 제 II형이 가장 많았으며 제 V형은 전혀 분리되지 않았다. 응고효소형의 병동별 분포는 일반외과에서 제 II형이, 이비인후과 외래에서는 제 IV형이 우점종으로 분리되었다. 항균제 감수성 시험결과, vancomycin과 teicoplanin에서 전균주가 감수성을 나타내었었고 penionillin, cephalothin, erythromycin, gentamycin, imipenem, clindamycin, ciprofloxacin과 oxacillin등 8가지의 항균제에 대하여 동시내성을 나타낸 균주가 71주 (81%)였다. 항균제 내성과 응고효소형과의 상관관계는 없었다.