• 한국동물위생학회지
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• 제47권1호
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• pp.27-33
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• 2024

At the present study, it was aimed to explore the states of antimicrobial resistant Staphylococcus aureus isolates from 1,360 chickens, pigs and cattle carcass (400 chickens, 480 pigs and 480 cattle) in Daegu province from January 2022 to December 2022. Among 1,360 samples, 81 of S. aureus were isolated cattle (1.4%), pigs (7.7%) and chickens (9.2%). In antimicrobial susceptibility test, all of the isolates were demonstrated susceptibility to rifampin. But the isolates were showed resistance other antibiotics in order of tetracycline (62.9%), ciprofloxacin (62.9%), tobramycin (58.0%), gentamicin (51.8%), amikacin (40.7%), penicillin (39.5%), clindamycin (35.8%), enrofloxacin (33.3%), trimethoprim/sulfamethoxazole (30.8%), oxacillin (30.8%), minocycline (29.6%), erythromycin (25.9%), quinupristin/dalfopristin (20.9%), chloramphenicol (12.3%), cefoxitin (9.8%). Among the 81 S. aureus isolates, 25 (30.8%) methicillin-resistant staphylococcus aureus (MRSA) were observed. Seven (28.0%) of 25 MRSA harbored mecA gene. About 96% of MRSA were multidrug resistance to at least 3 more drugs. A continuous monitoring and surveillance program to prevent antimicrobial resistance in livestock products is demanded.

• 대한임상검사과학회지
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• 제52권2호
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• pp.128-135
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• 2020

본 연구에서는 환자의 비강으로부터 분리 배양된 총 39건의 MRSA 분리 배양 균주를 이용해 mecA 유전자 검출, SCCmec typing과 mec complex typing을 분석해 보고자 하였다. 임상 환자의 비강으로부터 분리 배양된 MRSA 총 39주 중 SCCmec type-II가 24건, type-II/IVa가 2건, type-II/V가 1건, type-IVa가 1건, not-typeable이 11건으로 분석되었으며, mec complex type A가 29건, not-typeable이 10건이었으며, type B는 없는 것으로 분석 되었다. 결론적으로, 환자의 비강으로부터 분리된 MRSA 분리 배양 균주 중 SCCmec type-II와 mec complex type A 아형이 가장 많이 분포하고 있었으며, 이 결과는 의료기관 획득 MRSA에 관한 다른 연구결과와 유사한 결과를 나타냈다. 이후 환자의 비강으로부터 분리 배양된 not-typeable 아형의 MRSA 균주를 대상으로 국내에서 발견되는 새로운 MRSA 아형 규명에 관한 추가 연구가 필요할 뿐만 아니라, MRSA 분리 배양 균주의 아형을 분석함으로써 그 분자적 특성을 분석한 결과를 바탕으로 병원 감염관리를 위한 기초자료를 제공할 수 것으로 사료된다.

• Archives of Pharmacal Research
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• 제22권1호
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• pp.25-29
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• 1999

Psammaplin A, a natural bromotyrosine derivative from an associated form of two sponges (Poecillastra sp. and jaspis sp.) was found to possess the antimicrobial effect on the Gram-positive bacteria, especially on methicillin-resistant Staphylococcus aureus (MRSA). The minimal inhibitory concentration of psammaplin A against twenty one MRSAs ranged from 0.781 to 6.25 ${\mu}g/ml$, which that of ciprofloxacin was 0.391~3.125${\mu}g/ml$. Psammaplin A could not bind to penicillin binding protein, but inhibited the DNA synthesis and the DNA gyrase activity with the respective 50% (DNA synthesis) and 100% (DNA gyrase) inhibitory concentration 2.83 and 100 ${\mu}g/ml$. These results indicate that psammaplin A has a considerable antibacterial activity, although restricted to a somewhat narrow range of bacteria, probably by inhibiting DNA gyrase.

• IMMUNE NETWORK
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• 제21권2호
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• pp.13.1-13.19
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• 2021

Macrophages are important for the first line of defense against microbial pathogens. Integrin CD11b, which is encoded by Itgam, is expressed on the surface of macrophages and has been implicated in adhesion, migration, and cell-mediated cytotoxicity. However, the functional impact of CD11b on the inflammatory responses of macrophages upon microbial infection remains unclear. Here, we show that CD11b deficiency resulted in increased susceptibility to sepsis induced by methicillin-resistant Staphylococcus aureus (MRSA) infection by enhancing the pro-inflammatory activities of macrophages. Upon infection with MRSA, the mortality of Itgam knockout mice was significantly higher than that of control mice, which is associated with increased production of TNF-α and IL-6. In response to MRSA, both bone marrow-derived macrophages and peritoneal macrophages lacking CD11b produced elevated amounts of pro-inflammatory cytokines and nitric oxide. Moreover, CD11b deficiency upregulated IL-4-induced expression of anti-inflammatory mediators such as IL-10 and arginase-1, and an immunomodulatory function of macrophages to restrain T cell activation. Biochemical and confocal microscopy data revealed that CD11b deficiency augmented the activation of NF-κB signaling and phosphorylation of Akt, which promotes the functional activation of macrophages with pro-inflammatory and immunoregulatory phenotypes, respectively. Overall, our experimental evidence suggests that CD11b is a critical modulator of macrophages in response to microbial infection.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.799-805
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• 2016

Methicillin-resistant Staphylococcus aureus (MRSA), the major causative agent of nosocomial infection, has also been reported from non-human sources. A sequence type (ST) 541 MRSA isolate designated K12PJN53 was isolated from a healthy pig in 2012. The genome of K12PJN53 consists of 44 contiguous sequences (contigs), totalling 2,880,108 bases with 32.88% GC content. Among the annotated contigs, 14, 17, and 18 contained genes related to antimicrobial resistance, adherence, and toxin genes, respectively. The genomic distance of strain K12PJN53 was close to the ST398 strains. This is the first report of the draft genome sequence of a novel livestock-associated MRSA ST541 strain.

• Clinics in Shoulder and Elbow
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• 제16권2호
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• pp.141-147
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• 2013

회전근개 전층 파열과 원위 경골 관절면 골절 불유합을 동시에 시행한 57세 남자가 수술 19일만에 MRSA(Methicillin-resistant Staphylococcus aureus)에 의한 상완골두 급성 골수염이 발생하였다. 골수염은 3차례의 수술과 정맥 항생제 요법으로 치료되었으나 상완골두와 회전근개 결손은 남아있었다. MRSA에 의한 상완골두 골수염은 보고된 바가 없기에 문헌고찰과 함께 보고하는 바이다.

• Journal of Microbiology and Biotechnology
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• 제22권6호
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• pp.800-805
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• 2012

Licochalcone E was firstly isolated from licorice root in 2005, which belongs to the retrochalcone family. Studies on the biological activities of licochalcone E were in the initial stage. In the study, we demonstrated that licochalcone E has potent antimicrobial property against Staphylococcus aureus. Furthermore, via hemolysis, Western blot, and real-time RT-PCR assays, we have shown that subinhibitory concentrations of licochalcone E dose-dependently reduces the production of ${\alpha}$-toxin in both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The data suggest that licochalcone E may deserve further investigation as a potential therapeutic against S. aureus infections, or the structure of licochalcone E may be used as a basis for chemical synthesis of novel anti-S. aureus compounds.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2695-2699
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• 2011

${\beta}$ Ketoacyl acyl carrier protein synthase III (KAS III) initiates fatty acid synthesis in bacteria and is a key target enzyme to overcome the antibiotic resistance problem. In our previous study, we found flavonoid inhibitors of Enterococcus faecalis KAS III and proposed three potent antimicrobial flavonoids against Enterococcus faecalis and Vancomycin-resistant Enterococcus faecalis with MIC values in the range of 128-512 ${\mu}g/mL$ as well as high binding affinities on the order from $10^6$ to $10^7\;M^{-1}$. Using these series of flavonoids, we conducted biological assays as well as docking study to find potent flavonoids inhibitors of Staphylococcus aureus KAS III with specificities against Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus. Here, we propose that naringenin (5,7,4'-trihydroxyflavanone) and eriodictyol (5,7,3',4'-tetrahydroxyflavanone) are potent antimicrobial inhibitors of Staphylococcus aureus KAS III with binding affinity of $3.35{\times}10^5$ and $2.01{\times}10^5\;M^{-1}$, respectively. Since Arg38 in efKAS III is replaced with Met36 in saKAS III, this key difference caused one hydrogen bond missing in saKAS III compared with efKAS III, resulting in slight discrepancy in their binding interactions as well as decrease in binding affinities. 4'-OH and 7-OH of these flavonoids participated in hydrogen bonding interactions with backbone carbonyl of Phe298 and Ser152, respectively. In particular, these flavonoids display potent antimicrobial activities against various MRSA strains in the range of 64 to 128 ${\mu}M$ with good binding affinities.

• Journal of Korean Biological Nursing Science
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• 제21권4호
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• pp.283-291
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• 2019

Purpose: The aim of this study was to identify awareness and competency for Multi-Drug Resistant Organisms (MDRO) infection control in nursing students with experience of clinical practice. Methods: This cross-sectional descriptive study was conducted from March 2019 to May 2019 by including 231 nursing students in four nursing schools located in Seoul, Gyeonggi-do and Chungcheongnam-do. The data were collected using self-report questionnaires. Results: The awareness and the competency for Carbapenem-Resistant Enterobacteriaceae (CRE) infection control were lower than that of Methicillin-Resistant Staphylococcus aureus (MRSA). The agreement between the awareness and the competency of MDRO infection control in participants was low with regard to isolation, contact precautions, and disinfection for MRSA. Also, it was low with respect to disinfection, isolation, contact precautions, and carrier identification for CRE. The awareness and the competency of MDRO infection control exhibited significant positive correlation. Conclusion: The infection control competency is required to prevent MDRO infection. In order to enhance the infection control competency, it is important to raise awareness about MDRO infection control by providing education based on the guidelines and the principles of infection control.

• 한국균학회지
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• 제48권1호
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• pp.15-27
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• 2020

본 연구에서는 methicillin resistant Staphylococcus aureus subsp. aureus (MRSA) KCCM 40510 및 Bacillus cereus KCTC 3624 균주에 대한 항균활성을 보유한 균류 Penicillium rubefaciens NNIBRFG5039를 경북 상주시 도남동 공기 중으로부터 분리·동정하였고, 배양조건에 따른 균사체 생육 및 항균활성을 비교하였다. 그 결과, P. rubefaciens NNIBRFG5039는 PDB 배지, 배양온도 30℃, 초기 pH 6.5로 배양하였을 때 항균활성이 가장 높게 나타나는 것을 확인하였다. 최적조건하에서 5L fermenter를 이용하여 배양시간에 따른 균사체 건조중량 및 항균활성을 비교한 결과, 배양 5일째에 생장 및 항균활성이 가장 높았다. P. rubefaciens NNIBRFG5039의 배양여액의 항균활성 스펙트럼을 조사한 결과, methicillin-resistant Staphylococcus aureus subsp. aureus CCARM 3089·3090·3091·3095와 KCCM 40510, Bacillus cereus KCTC 3624, B.subtilis KACC 10111, Filobasidium neoformans KCTC 7902, Enterococcus faecalis KCCM 11814에 대해서도 항균활성을 가지는 것을 확인하였다. 또한, P. rubefaciens NNIBRFG5039의 배양여액으로부터 항균활성 후보물질을 각종 크로마토그라피법으로 순수분리하고, NMR과 ESI-MS 등의 기기분석을 실시하여 구조를 (S)-6-hydroxymellein (1)으로 동정하였다.