• Journal of Environmental Health Sciences
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• v.19 no.1
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• pp.71-76
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• 1993

Nasal carrige of Staphylococcus was studied in relation to its significance as a source of the Staphylococci that caused hospital-acquired infection. Due to the trend of the increasing r esistance of S. aureus to many antimicrobial agents, it is necessary to study the sensitivity to antibiotics of this infectious microorganisms. 50 persons from general hospital and 50 college students were the object of this study. The following results were obtained 3 0 Strains of S. aureus were isolated. The rate of S. aureus nasal carrying were 26% in college students and 34% in hospital personnel. S. aureus which showed resistance to penicillin were 90%, tetracyclin 43%, erythromycin 37% and oxacillin 17%. The number of penicillin resistance of S. aureus were 11 (84%) in college students and 16 (94%) in hospital personnel. The number of strains of penicillin resistant S. aureus which produced 13-1actamase were 9 (82%) in college student and 14 (88%) in hospital personnel. Methicillin-resistant S. aureus (MRSA) which showed resistance to erythromycin and penicillin G were 100%, tetracyline, cephalothin and clindamycin were over 40% respectively, gentamicin 20%, SAM 20% and chloramphenicol 0%.

• Biomedical Science Letters
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• v.11 no.4
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• pp.447-453
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• 2005

A total of 108 strains of MRSA (Methicillin-resistant Staphylococcus aureus) clinical isolates was collected from $121^{st}$ general hospital (U.S. military hospital), Korean healthcare facility from January to March in 2005 and Wonju Christian hospital in 1999. Antimicrobial susceptibility test by Vitek System and MIC test using oxacillin and cephalothin stripes by E-test were executed. PCR based detection of mecA gene was performed on the all of MRSA clinical isolates, too. MRSA clinical isolates were characterized with antimicrobial resistance patterns, PCR based detection of mecA gene and validation of the multiplex PCR strategy of SCCmec among clinical isolates.

• Natural Product Sciences
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• v.28 no.3
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• pp.93-104
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• 2022

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious threat to the global healthcare system. Ineffective and resistance to antibiotic treatments have increased morbidity and mortality rates worldwide. New and effective antibiotics are needed to combat against bacterial resistance. Endophytic fungi are crucial reservoirs of novel bioactive metabolites. In particular, the secondary metabolites show promising therapeutic potential, notably, antibacterial. This review discussed the emerging potential of endophytic fungi as anti-MRSA agents. The ecological sources of endophytic fungi were discussed with the synthesis of bioactive metabolites. The mode of antibacterial actions was elucidated to give a better understanding of the mechanisms involved. This review may serve as an important reference for future discovery and developments of anti-MRSA agents from endophytic fungi.

• KSBB Journal
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• v.14 no.4
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• pp.460-464
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• 1999

Methicillin-resistant Staphyloccus aureus (MRSA) has been known to be resistant to many kinds of antibiotics and causes a problem of nosnocomial infection since the third generation of cephalosporines has been introduced in the 1980s. As antibiotic sensitivity tests which have been routinely used to detect MRSA in the laboratory depend on the culture conditions such as, pH, temperature, and time, etc., it is difficult to decide in the case of borderline- or low-level of MRSA. Therefore it would be necessary to develope a new method based on the molecular biological technique to overcome these problems. In this study, we extracted DNA from S. aureus and performed polymerase chain reaction (PCR) to amplify mec A gene, encoding penicillin-binding protein 2' (PBP-2'), which is known to confer bacteria resistance to the bacteriostatic action of methicillin. The results were compares with those of minimal inhibitory concentration (MIC) test. When MIC test with oxacillin was performed on the 120 isolates of S. aureus from each patient's specimens, 64 of them were MRSA and 56 of them were methicillin-sensitive Staphylococcus aureus (MSSA). In pus specimen, more precisely, 61.9% (26/42) of MRSA was detected, and 44.2% (19/43), 60% (9/15) and 50% (10/20) of MRSA were detected in sputum, body fluid, and other specimen respectively. When 40 isolates of MRSA and MSSA were tested by PCR method and compares with the results of MIC method, different results were obtained from 1 isolate of MRSA (2.5%) and in 2 isolates of MSSA (5%) suggesting that PCR method should be performed at the same time for more accurate clinical test of MRSA.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.227.2-227.2
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• 2003

In the situation of high bacterial resistance to antibiotics in Korea, to assess diffusion of methicillin-resistant Staphylococcus aureus (MRSA) and levels of bacterial resistance to antibiotics in community, we monitored antibiotic resistance of S. aureus isolates from healthy volunteers of community. (omitted)

• 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.

• YAKHAK HOEJI
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• v.37 no.6
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• pp.621-624
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• 1993

The clirical isolate Staphylococcus aureus SA2 had four kinds of plasmids and was resistant to ampicillin, chloroamphenicol, clindamycin. erythromycin, gentamicin, kanamycin, methicillin, streptomycin, tetracycline and tobramycin. Transformation experiment demonstrated that 4.14kb plasmid(pKH7) encoded resistance to chloramphenicol. The cleavage map of pKH7 was determined by restriction enzyme mapping techniques. The cleavage map is given for BstEll, Hindlll, Hpall, and Xbal. The above restriction endonucleases have a single site, but nucleases BamHl, Bgll, BglII, EcoRl, EcoRV, HaeIII, Hpal, Kpnl, Pstl, PvnII, Sall, Smal, and XhoI have no site on this plasmid.

• Korean Journal of Microbiology
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• v.36 no.3
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• pp.216-220
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• 2000

Eighty-eight strain3 o~methicillin resistant Stopllylococcus awecis were Isolated from pus (64.7%); spuhm (26.2%), blood, fluid, andurine of 83 patients at Dong-A Hospital in P~~san to invesligate theil-coagulase typ- Ing, and multi-drug resistaut ppattems. The presence of niec A gene confe~~ing melhicillin resistance was tested by polymerase chain reaction (PCR) with uwo mec A gene specific primers using purified clromosonlal DNA as templates. DNA fragments of expected size wel-e detected frorn 86 strains, but not from two strains. !i coagulase typmg, the 86 isolates were assigned to 5 coagulase lypes, I, 11, lll. 1V, VI, VII, VIlI, but there was no isolate helong lo type V. The most abundant coagulase type was type TI(50 %), lollowed by type IV Rest ofthe coagulase types were ininor; ranging fmm 4.5 to 12.5 '% Most of the type I1 ~netlucillin resistant Stapl\ulcorneryiococcus nwem (MRSA) strams were isolated from the generd sulzely ward, but major strains of type IV were Isolated from the otorhinolq~ngology of the hospital's outpatient clinic center. All of the 88 st~nins were sensitive to vancomycin and teicoplanin, but 71 (81%) strains showed multi-drug resitant to penicillin, cephalotl~n, eiythroinycin, gentan~ycin, imipenem, clindamycin, ciprofloxacin and ooxacillin. Yo relationship was found between the antibiotic resistance pattems aud the coagulase typing patterns.

• Pediatric Infection and Vaccine
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• v.3 no.2
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• pp.133-138
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• 1996

Purpose : In the treatment of MRSA infection, rapid detection of MRSA is extremely important. The mecA gene codes the new drug resistant polypeptides called PBP2' which mediates the clinically relevant resistance to all beta-lactam antibiotics. The identical mecA gene has been found in coagulase-negative staphylococcus with the methicillin-resistant phenotype. On the other hand, the femA gene was absent from coagulase negative staphylococcus strains with the methicillin resistant phenotype. This study is aimed at early detection and definite diagnosis of MRSA. Methods : A total of 24 MRSA strains were studied. All strains were tested for antimicrobial susceptibility and purified DNA. We amplified both mecA and femA genes by PCR in 24 strains. Results : In MRSA all the 16 strains (100%) carried femA gene and 11 strains (68.7%) carried mecA gene. In contrast, in methicillin sensitive staphylococcus all the 8 strains (100%) carried femA and only 3 strains (37.5%) were detected mecA. Conclusions : As results, there are difference in the phenotype and genotype of methicillin resistance by PCR of mecA and femA. Such disparities between methicillin resistance and the presence of mecA gene suggest the presence of control gene of the mecA.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.2
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• pp.21-35
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• 2018

Objectives The objective of this study is to determine the antimicrobial effect of Daehwanggyeonu-san(Dahwangqianniu-san,DGE) and synergistic effects with antibiotics oxacillin, ampicillin, and gentamicin against Methicillin-Resistant Staphylococcus aureus(MRSA). Methods The antibacterial activity of DGE extract was evaluated againest MRSA strains by using the Disc diffusion method, broth microdilution method(minimal inhibitory concentration; MIC), checkerboard dilution test. The checkerboard dilution test was used to examined synergetic effect of oxacillin, ampicillin, gentamicin, ciprofloxacin with DGE extract. Results DGE showed antimicrobial activity against MRSA with an MIC value of $125{\sim}250{\mu}g/mL$. In the checkerboard test, the interation of DGE with all tested antibiotics produced almost synergy or partial synergy against MRSA. Conclusions This study shows that DGE reduced the MICs of several antibiotics tested, and a remarkable antibacterial effect of DGE, with membrane permeability enhancers and ATP synthase inhibitors. This study can be a valuable source for the development of a new drug with low MRSA resistance.