• Journal of Periodontal and Implant Science
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• 제45권6호
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• pp.223-228
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• 2015

Purpose: The goal of this study was to characterize the patterns of antimicrobial resistance and virulence genes in samples of Staphylococcus aureus (S. aureus) isolated from periodontitis patients. Methods: From July 2015 to August 2015, oral saliva was collected from a total of 112 patients diagnosed with periodontitis, including 80 outpatients in dental hospitals and 32 patients in dental clinics located in Seoul and Cheonan. The samples were subjected to a susceptibility test to evaluate the prevalence of antimicrobial resistance, and the pathogenic factors and antimicrobial resistance factors in the DNA of S. aureus were analyzed using polymerase chain reaction. Results: A susceptibility test against 15 antimicrobial agents showed that 88% of cultures were resistant to ampicillin, 88% to penicillin, and 2% to oxacillin. Resistance to at least two drugs was observed in 90% of cultures, and the most common pattern of multidrug resistance was to ampicillin and penicillin. Enterotoxins were detected in 65.9% of samples. The cell hemolysin gene hld was detected in 100% of cultures and hla was detected in 97.6% of samples. All strains resistant to penicillin and ampicillin had the blaZ gene. The aph(3')IIIa gene, which encodes an aminoglycoside modifying enzyme, was detected in 46.3% of samples. Conclusions: In the treatment of oral S. aureus infections, it is important to identify the pathogenic genes and the extent of antimicrobial resistance. Furthermore, it is necessary to study patterns of antimicrobial resistance and cross-infection in the context of periodontological specialties in which antimicrobials are frequently used, such as maxillofacial surgery, where the frequency of antimicrobial use for minor procedures such as implant placement is increasing.

• 대한미생물학회지
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• 제35권5_6호
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• pp.356-356
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• 2000

• Natural Product Sciences
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• 제13권3호
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• pp.251-254
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• 2007

Dioxopiperazine alkaloids, 12R,13S-dihydroxyfumitremorgin C (1), fumitremorgin C (2), and brevianamide F (3), were isolated from the marine-derived fungus Pseudallescheria, and the absolute stereostructures of compounds 1 - 3 were elucidated on the basis of chemical and physicochemical evidence. Compounds 1 - 3 showed an antibacterial activity against Staphylococcus aureus, methicillin-resistant S. aureus, and multidrug-resistant S. aureus. The MIC (minimum inhibitory concentration) values of compounds 1 - 3 were 125 ${\mu}g/mL$ for all strains.

• 대한의생명과학회지
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• 제19권3호
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• pp.245-253
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• 2013

To provide reference data or guideline for empirical treatment of bloodstream infection, we studied a change pattern in causative microorganisms and antimicrobial susceptibility in a general hospital at Gyeonggi province during five years. We retrospectively reviewed the frequency of causative microorganisms and antimicrobial susceptibility results of 5,782 microorganisms isolated from blood culture in a general hospital during the period from January 2008 to December 2012. The most common pathogens were Escherichia coli (14.7%), Staphylococcus aureus (7.5%), Streptococcus viridans group (4.9%), and Klebsiella pneumoniae (4.1%). The multiple microorganisms were isolated in 4.3% of bloodstream infection patients. The average contamination rate of blood culture during five years was 3.0%. Methicillin-resistant S. aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), and penicillin-resistant Streptococcus pneumoniae were isolated at 62%, 27% and 11%, respectively. Cefotaxime-resistant E. coli and K. pneumoniae was 20% and 18%, respectively. Imipenem-resistant Pseudomonas aeruginosa (IRPA) and Acinetobacter baumannii (IRAB) was 25% and 66%, respectively. E. coli and S. aureus were most common pathogens isolated from blood culture for five years. The increase of multidrug-resistant microorganisms, such as MRSA, VRE, ESBL, IRPA and IRAB, requires more strict control of antibiotics and causes the need of the more updated guideline for the treatment of blood stream infection.

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1635-1645
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• 2020

In this study would like to find extending or increasing the efficacy of the antibiotic substance for the strains with resistance to antibiotics or persister cells by inhibition of the resistance. This study was used different species of 'legal high' plants leaves from Leonotis leonurus, Mitragyna speciosa, and seeds from Ipomoea murucoides with antibiotics which are Amoxicillin, Chloramphenicol, Ciprofloxacin, Kanamycin, Oxacillin, and Vancomycin. Legal highs were extracted with methanol. Minimum inhibitory concentration(MIC) testing for a range of antibiotics with extracts of plant was fulfilled by broth dilution methods. In this essay, it was determined in a microdilution assay utilizing suspended in ISB up to a final concentration of 512㎍/ml in 96 wells microtitre plates, threefold and serial dilutions. After that, the microplates were kept in incubator between 35℃ and 37℃ for overnight. Leonotis leonurus, Mitragyna speciosa, and Ipomoea murucoides of Legal highs (512㎍/ml) investigated small activity to inhibit against pathogens which are susceptible Staphylococcus aureus, resistant Staphylococcus aureus, susceptible Enterococcus faecalis, resistant Escherichia coli.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1672-1676
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• 2010

The Actinomycete strain KH29 is antagonistic to the multidrug-resistant Acinetobacter baumannii. Based on the diaminopimelic acid (DAP) type, and the morphological and physiological characteristics observed through the use of scanning electron microscopy (SEM), KH29 was confirmed as belonging to the genus Streptomyces. By way of its noted 16S rDNA nucleotide sequences, KH29 was found to have a relationship with Streptomyces cinnamonensis. The production of an antibiotic from this strain was found to be most favorable when cultured with glucose, polypeptone, and yeast extract (PY) medium for 6 days at $27^{\circ}C$. The antibiotic produced was identified, through comparisons with reported spectral data including MS and NMR as a cyclo(L-tryptophanyl-L-tryptophanyl). Cyclo(L-Trp-L-Trp), from the PY cultures of KH29, was seen to be highly effective against 41 of 49 multidrug-resistant Acinetobacter baumannii. Furthermore, cyclo(L-Trp-L-Trp) had antimicrobial activity against Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Saccharomyces cerevisiae, Aspergillus niger, and Candida albicans, However, it was ineffective against Streptomyces murinus.

• 한국임상약학회지
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• 제22권2호
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• pp.181-186
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• 2012

Objective: To report a fatal case of Multidrug-resistant Acinetobacter baumannii (MDR-AB) in a patient with interstitial lung disease (ILD) on high-dose glucocorticoids. Case Summary: A 66-year-old man with a history of coniosis was transferred to the hospital with progressive cough and sputum production. This patient has been diagnosed with pneumonia and ILD on admission, requires antimicrobial therapy and systemic immunosuppressants. He received high dose of methylprednisolone and cyclophosphamide for ILD as well as ceftriaxone and azithromycin for pneumonia. On day 7 in the intensive care units (ICUs), patient had fever and leukocytosis, thus antimicrobials were switched to piperacillin. After 13 days in the ICU, Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA) were isolated on transtracheal aspirate (TTA) and meropenem was initiated. However, it was revealed a multidrug-resistant Acinetobacter baumannii (MDR-AB) species, resistant to carbapenem. Patient was administered colistin but expired due to septic shock on day 84. Discussion: Systemic immunosuppressive therapy can result in infections that may compromise patient's survival. MDR-AB has emerged as a serious cause of nosocomial infections in immunocompromised patients. MDR-AB is resistant to most standard antimicrobials and therapeutic options are limited. Conclusion: We report our recent experience with a fatal MDR-AB pneumonia in a patient with ILD, who had to be treated with high dose glucocorticoids and immunosuppressnts.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.354-359
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• 2003

Multiplex-PCR protocols were designed in order to make a rapid identification of MRSA. MecA, femB, and 165 rRNA genes were amplified for making a detection of MRSA. The incidence of MRSA in the clinical isolates of Staphylococcus aureus was examined by using a multiplex-PCR assay. The mecA gene was detected in 266 strains out of 336 clinical isolates of S. aureus, thus the incidence of MRSA was approximately 76.5%. The MRSAs of 247 strains (96.1%) showed resistance to more than eight species of the antimicrobial agents tested. The isolates of MRSA showed 27 different antimicrobial-resistant patterns. The results indicate that many different MRSA strains having high multidrug resistance are actually prevalent in Korea. Also, VISA was screened from the MRSA. Two strains were grown on the BHI agar plate supplemented with $8\;\mu\textrm{g}/ml$ of vancomycin at a frequency of $1/10^8$ colony forming units or higher.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1537-1546
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• 2022

Staphylococcus aureus is a cause of high mortality in humans and therefore it is necessary to prevent its transmission and reduce infections. Our goals in this research were to investigate the frequency of methicillin-resistant S. aureus (MRSA) in Taif, Saudi Arabia, and assess the relationship between the phenotypic antimicrobial sensitivity patterns and the genes responsible for resistance. In addition, we examined the antimicrobial efficiency and application of silver nanoparticles (AgNPs) against MRSA isolates. Seventy-two nasal swabs were taken from patients; MRSA was cultivated on Mannitol Salt Agar supplemented with methicillin, and 16S rRNA sequencing was conducted in addition to morphological and biochemical identification. Specific resistance genes such as ermAC, aacA-aphD, tetKM, vatABC and mecA were PCR-amplified and resistance plasmids were also investigated. The MRSA incidence was ~49 % among the 72 S. aureus isolates and all MRSA strains were resistant to oxacillin, penicillin, and cefoxitin. However, vancomycin, linezolid, teicoplanin, mupirocin, and rifampicin were effective against 100% of MRSA strains. About 61% of MRSA strains exhibited multidrug resistance and were resistant to 3-12 antimicrobial medications (MDR). Methicillin resistance gene mecA was presented in all MDR-MRSA strains. Most MDR-MRSA contained a plasmid of > 10 kb. To overcome bacterial resistance, AgNPs were applied and displayed high antimicrobial activity and synergistic effect with penicillin. Our findings may help establish programs to control bacterial spread in communities as AgNPs appeared to exert a synergistic effect with penicillin to control bacterial resistance.

• Pediatric Infection and Vaccine
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• 제20권2호
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• pp.63-70
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• 2013

목 적 : 본 연구에서는 CA-MRSA로 인한 소아의 세균성 근골격계 감염의 임상양상을 연구하기로 하였다. 방 법 : 2000년 9월부터 2012년 8월까지 12년간 분당 차병원에 입원한 18세 이하의 환아 중 혈액과 관절액, 조직이나 고름의 세균 배양검사에서 S. aureus가 동정된 환아를 대상으로 의무기록을 후향적으로 분석하였다. 결 과 : 대상 환아 수는 총 31례였으며 중간값은 7세(최소 17일, 최대 18세)이다. 화농성 관절염으로 진단된 경우는 11례(35.5%), 골수염은 16례(51.6%), 화농성 관절염과 골수염이 병발된 경우는 5례(16.1%)였다. 환아의 혈액이나 관절액, 조직이나 고름 등에서 동정된 S. aureus 31례 중 MSSA는 25례(80.6%), MRSA는 6례(19.4%)였다. 검출된 균주 중 다제내성균은 관찰되지 않았다. MRSA가 배양되었던 6례는 모두 2006년 이후 발생하였다. 모든 증례에서 항생제가 투여되었으며 항생제 투여 기간은 $26.4{\pm}12.7$일이었고, 첫 항생제로 반코마이신을 동반 사용한 경우는 4례(12.9%)였으며 10례(32.3%)에서 최종 항생제로 반코마이신이 투여되었다. 결 론 : 본 연구를 통하여 최근 12년간 세균성 근골격계 감염에서 MRSA의 발생은 연구기간 후반에 편중되었다.