• Journal of Korean Foot and Ankle Society
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• v.22 no.1
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• pp.38-43
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• 2018

Purpose: Treatment of diabetic foot infection due to methicillin-resistant Staphylococcus aureus (MRSA) remains challenging. Applying vancomycin-impregnated cement is one of the best methods of treatment. Vancomycin-impregnated cement has been used worldwide; however, to date, there is a limited number of studies regarding its use. We evaluated the duration of antimicrobial activity of vancomycin-impregnated cement stored at room temperature after manufacturing. Materials and Methods: The vancomycin-impregnated cement was manufactured by mixing 1 g of vancomycin with 40 g of polymer and adding 17.90 g of liquid monomer. The cement dough was shaped into flat cylinders with diameter and height of 6 mm and 2 mm, respectively. Another cement of the same shape without mixing vancomycin was prepared as the negative control. All manufactured cements were sterilized with ethylene oxide gas and stored at room temperature. Each cement was placed on Mueller Hinton agar plate lawned with standard MRSA strain. Standard vancomycin disk and gentamicin disk were placed together. After 24 hours, the diameter of inhibition zone was measured, and if the diameter was less than 15 mm, vancomycin-impregnated cement was regarded as a loss of antimicrobial activity. The study was repeated every 2 weeks until vancomycin-impregnated cements lost their antimicrobial activity. Results: Vancomycin-impregnated cement stored for a duration of 16 weeks created a 14 mm inhibition zone, while vancomycin disk created a 15 mm inhibition zone. Vancomycin-impregnated cement stored for a duration of 17 weeks created 7 mm and 9 mm inhibition zones, while vancomycin disk created 16 mm and 15 mm inhibition zones, respectively. Conclusion: We found a decrease of antimicrobial activity in vancomycin-impregnated cements after 16 weeks. After 17 weeks, they showed definite loss of antimicrobial activity. Therefore, we recommend not using vancomycin-impregnated cement spacers that has been stored for more than 16 weeks at room temperature.

• Biomedical Science Letters
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• v.16 no.2
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• pp.75-82
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• 2010

The molecular epidemiological characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolates have demonstrated their genetic diversity and evolution. A total of 137 strains of MRSA clinical isolates was collected from Korean healthcare facility in 2007. The MRSA clinical isolates were analyzed by molecular typings (SCCmec element and agr locus typing), virule nce factor gene detections {(Panton-Valentine leukocidin (PVL), enterotoxin, exfoliative toxin and toxic shock syndrome toxin-1), and amplified fragment length polymorphism (AFLP)}. The MRSA clinical isolates were classified as SCCmec type II-agr type 1 (2 strains), type II-agr type 2 (79 strains), type III-agr type 1 (24 strains), type III-agr type 2 (2 strains), type IV-agr type 1 (27 strains), type IV-agr type 2 (2 strains), and non-typable (1 strain, agr type 3). Based on SCCmec types, SCCmec type II (95.1%) and III (88.5%) indicated higher multidrug resistance rate than SCCmec type IV (10.3%) (P<0.001). The most common enterotoxin genes were seg (83.8%), sei (83.1%), and sec (80.2%). The tst gene was present in 86 out of 137 (62.8%) MRSA isolates. All MRSA isolates were negative for PVL and exfoliative toxin genes. The combinations of toxin genes were observed in particular SCCmec types; 97.6% of SCCmec type II strains carried sec, seg, sei and tst genes, 73.0% of SCCmec type III strains carried sea gene, and 89.7% of SCCmec type IV strains carried sec, seg and sei genes. Each of the SCCmec types of MRSA isolates had distinct AFLP profile. In conclusion, SCCmec type II, agr type 1 and 2 have demonstrated to be the most common types in Korea, and the results indicated that the virulence factors are closely associated with their molecular types (SCCmec and agr types).

• Journal of Environmental Health Sciences
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• v.42 no.4
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• pp.255-265
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• 2016

Objectives: Mobile phones have become one of the most essential accessories in daily life. However, they may act as reservoir of infectious pathogens if they are used without hygienic practices in their handling. Therefore, this study aimed to isolate food-borne pathogens from mobile phones and investigate the characteristics of toxin genes and antibiotic susceptibility patterns. Methods: A total of 146 mobile phones were collected from 83 middle- and 63 high-school students in Busan. The surfaces of the mobile phones were aseptically swabbed. Results: Among the food-borne pathogens, Staphylococcus aureus, Bacillus cereus and Escherichia coli were detected in 26 (17.8%), 20 (13.7%) and four (2.7%) samples, respectively. There were no statistically significant differences according to school level, gender or phone type. None of four E. coli strains had pathogenic toxic genes. All of the B. cereus strains carried at least three different toxin genes among the nine enterotoxin and emetic toxin genes. Three out of 20 B. cereus strains (15%) possessed emetic toxin genes, which are rarely detected in food-poisoning cases in Korea. Among the 26 strains of S. aureus, the detection rate of staphylococcal enterotoxin genes, toxic shock syndrome toxin (tsst) and factors essential for methicillin resistance (femA) were 84.6%, 7.7% and 100%, respectively. In the antibiotic susceptibility test, there was no methicillin-resistant S. aureus (MRSA) or vancomycin-resistant S. aureus (VRSA). Conclusion: The results show that students' mobile phones in Busan were contaminated by food-borne pathogens which carried various toxic genes. Therefore, regular phone disinfection and hand hygiene is important in order to reduce cross-contamination.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.96-104
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• 2013

Staphylococcus aureus is a major human pathogen that produces a wide array of toxins, leading to a number of adverse symptoms. We examined 275 strains of Staphylococcus aureus isolated from various foods between 2006 and 2008 for antimicrobial susceptibility. At least 259 (94.2%) of the tested strains showed antibiotic resistant properties, and 106 (40.7%) of them showed multiple antibiotic resistance. Eleven of the tested strains were resistant to oxacillin and mec A-positive. Moreover, oxacillin-resistant strains were significantly more likely to be multi-drug resistant (p < 0.01). Of the 275 isolates tested, 24.4% were noted as being positive for slime production and 30.5% were positive for biofilm assay. Antibiotic resistance was not associated with a significantly higher prevalence of biofilm formation. Twenty strains were classified using the DiversiLab system. Most of the strains could be classified into 2 clusters and 4 unique types. All 10 mec A-positive strains (cluster I) were grouped together into the same sub-cluster. Cluster II (6 strains) was not found to be resistant to oxacillin in this study. Although the prevalence of methicillin-resistant S. aureus in food is currently low, the risk of its transmission through the food chain cannot be disregarded.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.12-12
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• 1997

CFC-222 is a novel fluoroqinolone antibacterial agent synthesized and under development by the Cheil Jedang Corporation, Korea. CFC-222 exerts the antibacterial activity by inhibition of bacterial DNA gyrase leading to bactericidal action. In in vitro and in vivo preclinical testing, CFC-222 has been shown to possess a broad spectrum of antibacterial activity. In particular CFC-222 is very potent against Gram-positive bacteria such as Staphylococcus spp., Streptocuccus spp. (in particular penicillin G-resistant and -susceptible S. pneumoniae) and Enterococcus spp. when compared to other quinolones (ciprofloxacin, ofloxacin or lomefloxacin). CFC-222 also showed potent activity against the methicillin resistant clinical isolates of S. aureus (MRSA). Against Gram-negative bacteria (E. coli, Pseudomonas and Sarcina) the activity of CFC-222 was slightly weaker than that of ciprofloxacin, but was more potent than that of ofloxacin or lomefloxacin. In urinary systemic infections caused by both Gram-positive and -negative bacteria, CFC-222 demonstrated a potent therapeutic efficacy in particular against Cram-positive bacteria S. aureus, S. pyrogen 203 and S. pneumonia TypeIII.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.1
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• pp.103-111
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• 2021

The purpose of this study is to investigate the antibacterial efficacy of cotton and silk/rayon fabrics dyed with Saururus chinensis extract against antibiotic-resistant strains. The concentration of the concentrated dye in the Saururus chinensis extracts was 1.1% (o.w.f), and the liquor ratio was 1:10 at 30-70℃. The mordanting method was a post mordanting method. The concentration of Al2(SO4)3, CuSO4 5H2O and FeSO4 and7H2O mordant was 5% (o.w.f), and the liquor ratio was 1:40. In order to assess the antimicrobial activity of naturally dyed fabrics, Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591, was used by incubating it in Brain Heart Infusion Agar (BHA) including Oxacillin (2㎍/ml) and Fungizone (2.5㎍/ml) and Brain Heart Infusion broth (BHI; Detroit, MI, USA.) The investigation of the reduction of the rate of antibiotic-resistant strains to dyed cotton fabrics and silk/rayon fabrics revealed that Cu mordanting fabric has the highest antimicrobial effects, with the rate of 99.7%, and Fe mordanting fabric has the lowest, with 77.7%. Non-mordant cotton fabrics also show a high reduction rate of strains (94.6%). In the case of dyed silk/rayon fabrics, it indicates a high reduction in the rate of strains in all fabrics with non-mordant treatment (94.2%), Al mordanting (99.6%), and Cu and Fe mordanting(99.9%).

• Pediatric Infection and Vaccine
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• v.26 no.1
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• pp.11-21
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• 2019

Purpose: We aimed to investigate the epidemiological characteristics of Staphylococcus aureus bacteremia in Korean children. Methods: We retrospectively collected and analyzed data from the medical records of the patients with S. aureus bacteremia ${\leq}18years$ of age in Gil Medical Center from 2002 to 2016. Results: A total of 212 SAB cases were detected. The annual incidence of SAB from 2002 to 2016 ranged from 0.77 to 1.95 per 1,000 patients hospitalized. The neonate group (<28 days of age) and the pediatric group (28-18 years of age) were 51.4% (n=109) and 48.6% (n=103), respectively. According to the origin of infection, there were 93 cases (43.9%) of community-associated (CA)-SAB and 119 cases (56.1%) of healthcare-associated (HA)-SAB. The rates of HA-SAB among the neonate group and among the pediatric group were 64.2% and 47.6%, respectively (P=0.015). There was no difference in complications between CA-SAB and HA-SAB, but mortality was higher in HA-SAB. The proportion of methicillin-resistance S. aureus (MRSA) was the highest in neonates (88.1%), decreased with age, and was 36.4%-37.5% among children aged ${\geq}5years$. The MRSA proportion was 72.2%, showing no consistent trend over the period. Conclusions: The annual incidence of SAB and the proportion of MRSA in SAB remained constant in the recent 15 years in children. Judicious decision of antimicrobial agents for treatment considering the patient's age and the origin of infection is necessary.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.637-642
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• 2010

We investigated the prevalence and the molecular characteristics of vancomycin-intermediate Staphylococcus aureus (VISA) among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from clinical samples at tertiary or general hospitals participating in a nationwide surveillance program for VISA and vancomycin-resistant Staphylococcus aureus (VRSA) in Korea during an 8-week period in each year from 2001 to 2006. Of 41,639 MRSAs isolated, 37,856 were screened and 169 grew on brain heart infusion agar supplemented with 4 ${\mu}g/ml$ vancomycin. A vancomycin MIC of 4 ${\mu}g/ml$ was confirmed for 33 VISA isolates of the 169 isolates. Eighteen of the 33 isolates were classified as hetero-VISA (hVISA) by the population analysis profile (PAP) method. All VISA isolates were susceptible to linezolid, tigecycline, and quinupristin-dalfopristin. Most VISA isolates (MIC 4 ${\mu}g/ml$) showed a PFGE C pattern with sec, seg, and sei enterotoxin genes, including ST5-SCCmec type II, or a PFGE A pattern with sea, including ST239-SCCmec type III.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.516-521
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• 1995

In order to find a potent anti-methicillin resistant Staphylococcus aureus (MRSA) antibiotic, actinomycetes isolated from the samples collected in Korean marine silt were screened. From the culture broth of the isolated Streptamyces strain AM045, a substance showing excellent biological activity against MRSA was found, isolated and named AM3. The compound showed strong activities against MRSA, S. epidermidis, E. faecium and E. faecalis, which were better than those of vancomycin and teicoplanin. Unfortunately, AM3 was identified as Actinomycin V. However, this paper reports the three dimensional study of AM3 based on high resolution nmr and Computer Aided Molecular Modeling(CAMM), and the fact that the structure of the pentapeptide lactone ring with oxo-proline in chloroform solution does not have 'C conformation' any more.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.152-161
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• 2014

The in vitro antimicrobial potential of the unexplored Moringa oleifera seed coat (SC) was evaluated against some Gram-positive and Gram-negative bacteria and yeast pathogens. Antimicrobial studies with various solvent extracts indicated ethyl acetate to be the best extractant, which was used for the rest of the antimicrobial studies as it tested neither toxic nor mutagenic. Gram-positive bacteria including a methicillin resistant Staphylococcus aureus (MRSA) strain were more susceptible with a minimum inhibitory concentration (MIC) range of 0.03-0.04 mg/ml. The antimicrobial pharmacodynamics of the extract exhibited both concentration-dependent and time-dependent killing. Most of the test organisms exhibited a short post antibiotic effect (PAE) except Enterococcus faecalis, Staphylococcus aureus, and Klebsiella pneumoniae 1, which exhibited longer PAEs. Amongst the major phytoconstituents established, flavonoids, diterpenes, triterpenes and cardiac glycosides exhibited inhibitory properties against most of the test organisms. The identified active phytochemicals of the M. oleifera seed coat exhibited antimicrobial potential against a wide range of medically important pathogens including the multidrug-resistant bugs. Hence, the M. oleifera seed coat, which is usually regarded as an agri-residue, could be a source of potential candidates for the development of drugs or drug leads of broad spectrum that includes multidrug-resistant bugs, which are one of the greatest concerns of the $21^{st}$ century.