• 생약학회지
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• 제47권2호
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• pp.122-127
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• 2016

Methicillin-Resistant Staphylococcus aureus(MRSA) is a multidrug-resistant(MDR) strain. (+)-Usnic acid(UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against 17 different strains of the bacterium. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid(EDTA) was used. In the other hand, Sodium azide($NaN_3$) was used as inhibitors of ATPase. Against the 17 strains, the minimum inhibitory concentrations(MICs) of UA were in the range of $7.81-31.25{\mu}g/ml$. EDTA or $NaN_3$ cooperation against MRSA showed synergistic activity on cell wall. UA and in combination with EDTA and $NaN_3$ could lead to the development of new combination antibiotics against MRSA infection.

• Pediatric Infection and Vaccine
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• 제26권1호
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• pp.42-50
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• 2019

목적: 경남 창원지역에서 발생한 포도알균 열상 피부 증후군의 임상 및 역학적 특징을 알아보았다. 방법: 2006년부터 2015년까지 포도알균 열상 피부 증후군으로 진단받은 69명의 환자들을 대상으로 의무기록을 검토하였다. 항생제 감수성 검사는 Clinical and Laboratory Standards Institute의 지침에 따라 한천 평판 우무 희석법을 시행하였으며, MRSA는 oxacillin 감수성검사로표현형을확인한후, mecA 유전자를 polymerase chain reaction로증폭하여최종확인하였다. 결과: 환자들의 중간연령은 2.0세이었고(범위, 0.2-6세) 임상형은 전신형이 3명(4.3%), 중간형이 53명(76.8%), 부전형이 13명(18.9%)이었다. 환자들은 연중 발생하였으나, 주로 7월부터 10월 사이에 많이 발생하였다. 배양검사를 실시한 60명의 환자 중 54명에게서 MRSA 균이 배양되었고 모든 환자들이 특별한 합병증 없이 회복되었다. 결론: 2006년부터 2015년 사이에 창원지역에서 포도알균 열상 피부 증후군 환자의 지속적인 발생이 있었다. SSSS 환자 발생에 대한 지속적인 모니터링이 필요할 것으로 생각된다.

• Natural Product Sciences
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• 제24권4호
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• pp.225-228
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• 2018

By activity-guided fractionation, gliotoxin was isolated as an antibacterial metabolite of the fungus Penicillium decumbens which was derived from the jellyfish Nemopilema nomurai. Gliotoxin was further evaluated for antibacterial activity against several piscine and human MDR (multidrug resistance) pathogens. Gliotoxin showed significant antibacterial activity against Gram-positive piscine pathogens such as Streptococcus iniae FP5228, Streptococcus iniae FP3187, Streptococcus parauberis FP3287, Streptococcus parauberis SPOF3K, S. parauberis KSP28, and Lactococcus garvieae FP5245. Gliotoxin showed strong activity especially against S. parauberis SPOF3K and S. iniae FP5228, which are resistant to oxytetracycline. It is noteworthy that gliotoxin effectively suppressed streptococci which are the major pathogens for piscine infection and mortality in aquaculture industry. Gliotoxin also showed strong antibacterial activity against multidrug- resistant human pathogens (MDR) including Enterococcus faecium 5270 and MRSA (methicillin-resistant Staphylococcus aureus) 3089.

• Child Health Nursing Research
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• 제22권4호
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• pp.379-389
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• 2016

Purpose: A longitudinal study was conducted to explore flora colonization and oral glucose high-risk newborns during the first 7 days after birth. Methods: Oral secretions of hospitalized newborns were obtained for microbial cultures and glucose test at days 1-7 after birth. Results: Among the total 112 newborns, 40% were girls and 73% were premature. Mean gestational age was $34.4{\pm}3.2$ weeks and weight was $2,266{\pm}697.5$ grams. The most common flora included Streptococcus (28.2%), Methicillin-resistant Staphylococcus aureus (MRSA, 10.9%), Staphylococcus (6.0%) and Coagulase-Negative Staphylococcus (CNS, 4.0%). The average oral glucose level was $29.2{\pm}23.0mg/dL{\sim}58.2{\pm}39.5mg/dL$. Newborns with higher oral glucose than serum (crude odds ratio [ORc] =1.75; 95% confidence interval [CI] =1.03-2.97), phototherapy (ORc=3.30; 95% CI=2.29-4.76) and prone position (ORc= 2.04; 95% CI=1.13-3.69) were more likely to be colonized. Having oral tubes (ORc=0.42; 95% CI=0.29-0.59), parental nutrition (ORc=0.21; 95% CI=0.13-0.32) and antibiotics (ORc=0.51; 95% CI=0.36-0.73) had protective effects. For oral glucose statistical significances existed on time effect among newborns with Streptococcus (F=9.78, p=.024), MRSA (F=7.60, p=.037) or CNS (F=11.15, p=.019) and interaction between time and colonization among newborns with all of four flora (F=2.73, p=.029) or colonization with only Staphylococcus (F=2.91, p=.034). Conclusion: High-risk newborns develop flora colonization at an early period of life. Their clinical features were associated with types and time of oral flora colonization. They need close monitoring and multifaceted intervention to improve oral environment and infection control.

• Clinics in Orthopedic Surgery
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• 제10권4호
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• pp.427-432
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• 2018

Background: The purpose of this study was to evaluate the usefulness of sonication technique for microbiological diagnosis and the sterility of the recycled autoclaved femoral components from infected total knee arthroplasty (TKA) using a sonication method. Methods: Nineteen femoral implants explanted from patients with infected TKA were sterilized with a standard autoclave method. Standard culture of the fluid before and after sonication of the sterilized implants was performed to detect pathogenic microorganisms. Additional experiments were performed to evaluate the sterility of the recycled implant by inducing artificial biofilm formation. Methicillin-resistant Staphylococcus aureus (MRSA) was inoculated into 10 implants and sterilization in a standard autoclave was performed, and then the fluid was cultured before and after sonication. Results: Two of the 19 sterilized implants were positive for growth of bacteria after sonication, whereas no growth was detected in the cultured fluid from the sterilized implants before sonication. The bacteria were Staphylococcus species in all two cases. In one of 10 implants inoculated with MRSA, the culture was positive for growth of bacteria both before and after sonication. However, Staphylococcus epidermidis was cultured from both occasions and thus this implant was thought to be contaminated. Conclusions: We found sonication for identification of pathogens could be helpful, but this finding should be interpreted carefully because of the possibility of contamination. Sterilization of an infected femoral implant with an autoclave method could be a good method for using the temporary articulating antibiotic spacer in two-stage revision arthroplasty.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.536-541
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• 2013

Background Pathogens in the nasal cavity during nasal surgery could lead to a systemic infectious condition, such as bacteremia, nosocomial infection, or toxic shock syndrome. However, there is no research about the prevalence of nasal carriage in patients with nasal bone fracture. Methods This was a prospective, double-blind, randomized study about the rate of nasal carriage in 200 patients with nasal bone fracture in Korea. Nasal secretions were taken from both the middle nasal meatus and colonized. All analyses were carried out using SPSS software. Results Pathogens were identified in 178 of the 200 cases. Coagulase-negative staphylococci (CNS) were the most cultured bacteria in 127 (66.84%) of the 190 total patients after excluding 10 cases of contaminated samples, and methicillin-resistant coagulase-negative staphylococci (MRCNS) were found in 48 (25.26%). Staphylococcus aureus was the second most identified pathogen, found in 36 (18.95%), followed by 7 cases (3.68%) of methicillin-resistant Staphylococcus aureus (MRSA). The prevalence rate of MRSA in the females was higher than that in the males (RR=4.70; 95% CI, 1.09-20.18), but other demographic factors had no effect on the prevalence rate of MRSA and MRCNS. Conclusions The prevalence rate of these pathogens in patients with nasal bone fracture in Korea was similar to other reports. However, few studies have addressed the prevalence rate of CNS and MRCNS in accordance with risk factors or the change in prevalence according to specific prophylaxis against infectious complications. Additional research is needed on the potential connections between clinical factors and microbiological data.

• Journal of Microbiology and Biotechnology
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• 제32권10호
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• pp.1284-1291
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• 2022

The rise of methicillin-resistant Staphylococcus aureus (MRSA) has resulted in significant morbidity and mortality, and clinical treatment of MRSA infections has become extremely difficult. Sortase A (SrtA), a virulence determinant that anchors numerous virulence-related proteins to the cell wall, is a prime druggable target against S. aureus infection due to its crucial role in the pathogenicity of S. aureus. Here, we demonstrate that isovitexin, an active ingredient derived from a variety of traditional Chinese medicines, can reversibly inhibit SrtA activity in vitrowith a low dose (IC₅₀=24.72 ㎍/ml). Fluorescence quenching and molecular simulations proved the interaction between isovitexin and SrtA. Subsequent point mutation experiments further confirmed that the critical amino acid positions for SrtA binding to isovitexin were Ala-92, Ile-182, and Trp-197. In addition, isovitexin treatment dramatically reduced S. aureus invasion of A549 cells. This study shows that treatment with isovitexin could alleviate pathological injury and prolong the life span of mice in an S. aureus pneumonia model. According to our research, isovitexin represents a promising lead molecule for the creation of anti-S. aureus medicines or adjuncts.

• 대한두경부종양학회지
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• 제38권1호
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• pp.59-63
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• 2022

The latissimus dorsi flap has high vascularity and is helpful for the reconstruction of infected areas. Herein, we present a patient with recurrent infections and soft-tissue defects who underwent cranial reconstruction using a free latissimus dorsi flap. The patient had undergone craniectomy and reconstruction using alloplastic bone 18 years previously. A scalp defect accompanied by infection occurred five years ago, and patient underwent reconstruction using a free flap at another hospital; however, the problem persisted. After debridement and bone flap removal, the right latissimus dorsi musculocutaneous flap was elevated, and the thoracodorsal artery and vein were anastomosed end-to-end to the right superficial temporal artery and vein. Methicillin-resistant Staphylococcus aureus was eradicated, and the flap survived. Cranioplasty was performed eight months later, and one year follow-up proceeded without complications. Effective reconstruction and cranioplasty are possible using the free latissimus dorsi musculocutaneous flap, even on scalp with persistent infections and soft-tissue defects.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.98-108
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• 2015

Staphylococcus aureus is an important foodborne pathogen that causes diverse diseases ranging from minor infections to life-threatening conditions in humans and animals. To further understand its pathogenesis, the genome of the strain S. aureus FORC_001 was isolated from a contaminated food. Its genome consists of 2,886,017 bp double-stranded DNA with a GC content of 32.8%. It is predicted to contain 2,728 open reading frames, 57 tRNAs, and 6 rRNA operons, including 1 additional 5S rRNA gene. Comparative phylogenetic tree analysis of 40 complete S. aureus genome sequences using average nucleotide identity (ANI) revealed that strain FORC_001 belonged to Group I. The closest phylogenetic match was S. aureus MRSA252, according to a whole-genome ANI (99.87%), suggesting that they might share a common ancestor. Comparative genome analysis of FORC_001 and MRSA252 revealed two non-homologous regions: Regions I and II. The presence of various antibiotic resistance genes, including the SCCmec cluster in Region I of MRSA252, suggests that this strain might have acquired the SCCmec cluster to adapt to specific environments containing methicillin. Region II of both genomes contains prophage regions but their DNA sequence identity is very low, suggesting that the prophages might differ. This is the first report of the complete genome sequence of S. aureus isolated from a real foodborne outbreak in South Korea. This report would be helpful to extend our understanding about the genome, general characteristics, and virulence factors of S. aureus for further studies of pathogenesis, rapid detection, and epidemiological investigation in foodborne outbreak.

• 대한방사선기술학회지:방사선기술과학
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• 제31권3호
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• pp.229-237
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• 2008

목적 : 검사실별 IP카세트와 테이블의 미생물 수와 세균학적 오염도를 알코올과 소독제가 포함된 티슈를 사용 전 후로 나누어 동정한 후 통계적으로 검정을 실시하여 영상의학과내 병원감염관리의 예방과 올바른 소독 지침을 위한 기초자료를 제공하고자 연구하였다. 대상 및 방법 : 본 연구는 대전광역시 소재의 1개 대학병원 영상의학과의 일반촬영실을 대상으로 하였다. 기간은 2007년 4월 5일부터 4월 12일까지 이루어졌으며, 검사실별 IP카세트와 테이블의 미생물 수와 세균학적 오염도를 알코올과 소독제가 포함된 소독용 티슈를 사용 전, 후로 나누어 실시하였으며, 정확한 수집을 위하여 병원내 감염관리 전문 간호사와 함께 시료를 채취하였다. 통계처리는 SPSS V13.0을 사용하였으며, 전 후 비교를 위해 T-검정을 실시하였으며 사후검증을 실시하였다. 결과 : 24개의 대상 중 19개(79.2%)에서 세균이 검출 되었으며 5개(20.8%)에서는 세균이 검출되지 않았다. 분리된 세균의 종류는 7종의 세균이 검출 되었는데 그 중 Methicillin Resistant coagulase-negative Staphylo-cocci(MRCNS)가 15(62.5%)곳으로 가장 많이 검출되었으며, 그 다음으로 Methicillin Resistant Staphylococcus Aureus(MRSA)가 6(16.7%)곳으로 많았으며, Enterococcus Faecium(EFM)이 5(20.8%), Acinetobacter baumannii(ABA) 2(8.3%), Bacillus sp, Coagulase-negative Staphylococci(CNS), Enterococcus sp(ENT)가 각각 1(4.2%)곳에서 검출되었다. 또한 ABA를 제외한 모든 것이 그람양성구균(Gram positive bacilli)이 30(97%) 례에서 검출 되었으며, 1(3%)례에서만 그람음성균(Gram positive bacilli)이 검출되었다. Group별 70% Alchol 사용 전 후 균의 종류 및 군락 수에서는 70% Alchol로 소독을 한 후 세균을 동정한 결과 70% Alchol 소독군에서는 IP Cassette와 Table 그룹 모두에서 100% 세균이 사멸되었다. Group별 Tissue Cleaner 사용 전 후 균의 종류 및 군락 수에서는 Tissue Cleaner 그룹에서의 균의 사멸률은 10그룹(71.2%)에서만 세균이 완전히 사멸되었으며, 4 그룹에서는 많은 감소를 보였으나 여전히 세균이 검출되었다. 전체 균의 사멸률은 91.5%로 나타났는데 다른 균들은 모두 사멸된 반면 MRCNS 균은 사멸률이 가장 낮았(83.6%)으며, 다음으로 MRSA(95%)가 낮았다. 결론 : 70% Alchol과 Tissue Cleaner의 사용전 후 검출되는 세균의 평균을 비교한 결과 모두에서 유의수준5%에서 통계적으로 유의한 것으로 나타났다.