• 약학회지
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• 제52권6호
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• pp.434-440
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• 2008

The purpose of this research was to investigate the microbiological quality and antimicrobial susceptibilities of the ready-to-eat side dishes, which are were collected from the grocery stores, big markets, and department stores in Seoul throughout November, 2007. Of total 124 samples, presence of staphylococci and enteric bacilli was observed in 38 samples (31%) and 53 samples (43%), respectively. And 30 samples (24%) were shown to be of unsatisfactory quality for total bacterial count (>$10^5$). Antimicrobial susceptibilities of the staphylococci isolated from the side dishes were tested for six different antimicrobial agents, which are in widespread clinical use in Korea, as well as four new antimicrobials, daptomycin, linezolid, quinupristin/dalfopristin and tigecycline. As a result, the staphylococcal isolates were found to be resistant to oxacillin (${MIC}_{90}$, >128 ${\mu}g$/ml), teicoplanin (${MIC}_{90}$, >128 ${\mu}g$/ml), mupirocin (${MIC}_{90}$, >128 ${\mu}g$/ml), linezolid (${MIC}_{90}$, 128 ${\mu}g$/ ml) and quinupristin/dalfopristin (${MIC}_{90}$, 32 ${\mu}g$/ml). Especially, some of the staphylococcal isolates exhibited high level and multi-drug resistance. Moreover, these bacteria were also resistant to new antimicrobials, except tigecycline.

• Advances in Traditional Medicine
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• 제5권1호
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• pp.57-61
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• 2005

Ethanol and aqueous extracts of Cassia auriculata were tested in vitro against fungi (Candida albicans and Microsporum canis) and bacteria (Escherichia coli, Salmonella enteriditis, Staphylococcus aureus and Bacillus subtilis). M. canis showed dose-dependent susceptibility only towards ethanol leaf and bark extracts. C. albicans, were resistant to all types of plant extracts. Results were statistically smaller to antifungal drug ketoconazole and miconazole at equivalent concentration. Both ethanol and aqueous extracts of Cassia auriculata leaves and barks exhibit antibacterial activity against S. aureus and only the ethanol extracts of leaf and bark were detected against Bacillus subtilis. The results were compared to antibacterial drugs chloramphenicol, ampicillin, penicillin G, and enrofloxacin. The antibacterial activity was statistically similar to penicillin G. Based on the current findings, it can be concluded that this plant has antimicrobial activity, which is as potent as standard antimicrobial drugs.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3219-3222
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• 2011

Three types of ${\beta}$-ketoacyl acyl carrier protein synthase (KAS) are important for overcoming the bacterial resistance problem. Recently, we reported the discovery of a antimicrobial flavonoid, YKAF01 (3,6-dihydroxyflavone), which exhibits antibacterial activity against Gram-positive bacteria through inhibition of ${\beta}$-ketoacyl acyl carrier protein synthase III (KAS III). In this report, we suggested that YKAF01 can be an inhibitor ${\beta}$-ketoacyl acyl carrier protein synthase I (KAS I) with dual inhibitory activity for KAS I as well as KAS III. KAS I is related to the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and can be a good therapeutic target of designing novel antibiotics. We performed docking study of Escherichia coli KAS I (ecKAS I) and YKAF01, and determined their binding model. YKAF01 binds to KAS I with high binding affinity ($2.12{\times}10^6$) and exhibited an antimicrobial activity against the multidrug-resistant E. coli with minimal inhibitory concentration (MIC) value of 512 ${\mu}g$/mL. Further optimization of this compound will be carried out to improve its antimicrobial activity and membrane permeability against bacterial cell membrane.

• 대한치과의사협회지
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• 제52권7호
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• pp.425-431
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• 2014

Objectives : The purpose of our study was to evaluate penicillin as a still drug of choice for severe endodontic infection, by analyzing the antimicrobial susceptibilities from endodontic infections with swelling to figure out appropriate antibiotics as empirical treatment. Materials and methods : This study involved 18 patients who attended for emergency treatment because of facial or periapical swelling associated with root canal infections. Identification and antimicrobial susceptibility test of each pathogen were performed by Vitek2 Systems (bioM$\acute{e}$rieux, Marcy l'Etoile, France). Results : The most frequent bacteria was Streptococcus spp.(77%), and the resistance against penicillin was 35% in overall patients, followed by clindamycin and erythromycin (17%), which was much higher than previous studies. Conclusions : In our study, the higher resistance made penicillin alone not to be chosen as the first antibiotic drug for severe endodontic infections. Combinations with other drug, penicillin with wider spectrum of activity, or changing to other antibiotics was considered while remembering the increased risk of resistant microorganism.

• 한국축산식품학회지
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• 제41권6호
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• pp.967-982
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• 2021

Probiotics are living microorganisms that, when administered in adequate amounts, provide a health benefit to the host and are considered safe. Most probiotic strains that are beneficial to human health are included in the "Lactic acid bacteria" (LAB) group. The positive effects of probiotic bacteria on the host's health are species-specific and even strain-specific. Therefore, evaluating the probiotic potential of both wild and novel strains is essential. In this study, the probiotic characteristics of Lactobacillus brevis KT38-3 were determined. The strain identification was achieved by 16S rRNA sequencing. API-ZYM test kits were used to determine the enzymatic capacity of the strain. L. brevis KT38-3 was able to survive in conditions with a broad pH range (pH 2-7), range of bile salts (0.3%-1%) and conditions that simulated gastric juice and intestinal juice. The percentage of autoaggregation (59.4%), coaggregation with E. coli O157:H7 (37.4%) and hydrophobicity were determined to be 51.1%, 47.4%, and 52.7%, respectively. L. brevis KT38-3 produced β-galactosidase enzymes and was able ferment lactose. In addition, this strain was capable of producing antimicrobial peptides against the bacteria tested, including methicillin and/or vancomycin-resistant bacteria. The cell-free supernatants of the strain had high antioxidant activities (DPPH: 54.9% and ABTS: 48.7%). Therefore, considering these many essential in vitro probiotic properties, L. brevis KT38-3 has the potential to be used as a probiotic supplement. Supporting these findings with in vivo experiments to evaluate the potential health benefits will be the subject of our future work.

• 미생물학회지
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• 제50권2호
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• pp.101-107
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• 2014

지역사회 획득 항생제 내성 세균은 전 세계에서 새로운 문제로 대두되고 있다. 특히 한국에서 항생제 내성 세균의 발생빈도는 다른 선진국들보다 높다. 본 연구에서는 서울지역의 다양한 주변 환경(가정집, 대학교, 대중교통, 소지품 등)으로부터 methicillin-resistant staphylococci (MRS), Pseudomonas, 그리고 대장균군(Enterobacteriaceae)의 분리율을 조사하였으며, 검출된 대장균군(Enterobacteriaceae)을 대상으로 신 항생제를 포함한 한국의 임상에서 널리 쓰이는 13종의 항생제에 대한 내성정도를 파악하였다. 총 239건의 시료에서 18건(7.5%)의 MRS, 10건(4.2%)의 Pseudomonas, 그리고 30건(12.6%)의 대장균군(Enterobacteriaceae)이 분리되었다. 또한 가정집에서 2건, 대학교에서 1건, 그리고 기타(공원 의자와 빌딩 문손잡이)에서 2건, 총 5건(2.1%)의 시료에서 메티실린 내성 황색포도상구균(methicillin-resistant Staphylococcus aureus, MRSA)이 검출되었으며, 대장균(Escherichia coli)은 가정에서 1건, 대중교통에서 3건, 그리고 기타(음식점 정수기 본체 상단)에서 1건, 총 5건(2.1%)의 시료에서 검출되었다. 분리된 대장균군(Enterobacteriaceae) 32균주에 대한 항생제 내성률은, cephalosporin 계열과 fluoroquinolone 계열에서 각각 71.9%, carbapenem 계열과 ${\beta}$-lactam 계열에서 각각 68.8%까지 나타났으며, tetracycline 계열과 aminoglycoside 계열에서는 각각 50.0%와 25.0%까지 내성을 나타냈다. 또한 trimethoprim/ sulfamethoxazole에 대한 내성률은 43.8%로 나타났다. 심지어 신 항생제인 tigecycline에 대한 내성률도 59.4%로 나타났으며, 시험한 모든 항생제에 내성을 나타내는 균주도 3건이나 검출되었다. 그리고 분리된 총 5균주의 대장균(E. coli)은 대부분의 시험 항생제에 내성을 나타냈으나, 일부는 ciprofloxacin과 gentamicin에 감수성을 보였다. 본 연구는 향후 주변환경의 항생제 내성 수준의 변화를 비교하기 위한 기초 자료를 제공하며, 이들 내성균의 발생과 확산 방지에 대한 다각적인 노력과 대책 마련이 필요함을 보여준다.

• 생명과학회지
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• 제26권2호
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• pp.220-225
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• 2016

본 연구는 치과 병의원 진료실 주변환경과 치과종사자의 휴대전화에서 분리된 coagulase-negative staphylococci (CNS)의 분리율과 항균제 내성양상 및 분자 역학적 특성을 분석하고자 하였다. 2014년 12월부터 2015년 1월까지 부산지역 10개의 치과 병의원에서 총 154개의 샘플을 수집하여 MALDI-TOF분석법을 통해 동정하였다. 항균제 감수성검사는 디스크 확산법을 시행하였고 mupA, mecA 유전자 보유현황 및 SCCmec type은 PCR과 염기 서열분석에 의해 결정하였다. 154개의 샘플 중 10개(6.5%)에서 CNS 균주(Staphylococcus epidermidis 5주, Staphylococcus capitis 2주, Staphylococcus warneri 2주, Staphylococcus haemolyticus 1주) 가 분리되었다. 항균제 감수성검사에서 penicillin 10주, mupirocin 6주, gentamicin 5주, tetracycline 3주 및 cefoxitin과 erythromycin 2주가 내성이었고 clindamycin, ciprofloxacin, teicoplanin, trimethoprim-sulfamethoxazole에 내성인 세균은 없었다. 2개의 CNS균주(S. warneri, S. haemlyticus)에서 mecA 유전자가 검출되었고 1개의 CNS균주(S. epidermidis)에서 mupA가 확인되었다. Methicillin 내성 CNS균주 가운데 1주는 SCCmec I형이었고 1균주는 SCCmec의 유전형이 구분되지 않았다. 본 연구를 통하여 다약제 내성을 보이는 CNS균주가 더 이상 우리나라 치과병의원 환경에서 드물지 않음을 알 수 있었다.

• 대한임상검사과학회지
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• 제49권4호
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• pp.413-419
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• 2017

폐렴의 한(일개) 환자의 임상검체에서 연속적으로 분리된 Imipenem 내성세균 4균주를 분리하였다. 분리균을 동정하기 위해 Vitek II system의 GN card를 이용하였으며 16S rRNA유전자 염기서열을 기초로 계통학적 분석을 실시하였다. 분리균은 P. aeruginosa (2 strains), P. monteilii (1) 및 P. putida (1) 으로 동정되었다. 분리균들의 항생제에 대한 내성시험은 Vitek II system AST-N225 card를 이용해서 imipenem의 최소억제 농도가 모두 $${\geq_-}8{\mu}g/mL$$을 확인한 후 실험에 사용하였다. ${\beta}-Lactamase$ 유전자의 특이 시발체를 이용하여 증폭한 PCR 산물로 imipenem 내성 유전자형을 결정하였는데 분리된 4균주 모두에서 MBL 유전자를 확인하였으며 2균주의 P. aeruginosa는 MBL유전자중 VIM형과 SHV형 유전자를 그리고 또다른 균주는 VIM형과 OXA group II형 유전자를 동시에 보유하고 있었다. 항생제 감수성 결과에서는 amikacin이 다른 항생제보다 감수성을 보였을 뿐 대체적으로 내성율이 높았다. 균주들간의 역학적 연관성 분석을 위해 ERIC-PCR을 이용한 DNA 지문 분석결과, 분리된 2 균주의 P. aeruginosa는 유사한 균주일 것으로 추정하였으나 DNA band 유형의 상동성은 서로 다른 유형임을 알아 볼 수 있었다. 특이하게 한 환자에게서 imipenem 내성세균이 4균주가 검출 된 것은 이례적이며 동종의 DNA band 유형도 서로 상이하였다.

• 한국자기공명학회논문지
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• 제21권3호
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• pp.78-84
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• 2017

Pseudin is a naturally occurring 24 amino-acid-residue antimicrobial peptide derived from the skin of paradoxical frog Pseud's paradoxa. It shows potency against the bacteria and antibiotic-resistant bacteria strain, but has high cytotoxicity against mammalian cell. In our previous study, substitution of $Pro^{11}$ for Gly (Ps-P) increased bacterial cell selectivity but decreased the antibacterial activity of pseudin. In this study, we designed pseudin analogue, Ps-4K-P with increased cationicity up to +7 in Ps-P by substituting Glu14, Gln10, Gln24, and Leu18 with Lys. Ps-4K-P showed improved potent antibacterial activity with high bacterial cell selectivity. We determined the tertiary structure of Ps-4K-P in the presence of DPC micelles by NMR spectroscopy and it has a hinge structure at $Pro^{11}$ followed by three turn helices from $Pro^{11}$ to $Val^{23}$ at the C-terminus. Amphipathicity with increased cationicity as well as helix-hinge-helix structural motif provided by introduction of a Pro at position $Gly^{11}$ are the crucial factors which confer antibacterial activity with bacterial cell selectivity to Ps-4K-P.

• 한국동물위생학회지
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• 제15권1호
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• pp.81-88
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• 1992

This study was conducted to determine the microorganisms inhabitating in sow genital organs and their anti-microbial drug susceptibility During the period between February, 1991 and November 1991, 128 sow genital organs were sampled at six abattoirs. Gross pathological examination and bacterial isolation and identification were performed from the genital organ. In addition, antimicrobial drug susceptibility for the major organisms isolated were examined. 1. Among the bateria isolated from normal genital organs, E. coli(30.7%) Stahylococcus spp.(29.4%), Corynebarterium pyogenes(C. pyogenes) (14.7%), Streptococcus spp.(13.3%) were most freqently isolated, whereas the genera of Klebsiella, Actinobacillus, and Serratia were detected less freqently. 2. Among the bacteria isolated from abnormal genital organs, C. pyogenes,(37.7%), Stahylococcus spp.(30.2%), Proteus spp. (26.4%) , Pasteurella spp. (18.9%) , Steptococcus spp. (9.4%) were most freqently isolated whereas the genera of Pseudomonas, Serratia and Klebsiella were detected less freqently. 3. From sow genital organs showing lesion of endometritis and purulent endometritis C. pyogenes were most freqently isolated, the isolation rate being 67.7％ and followed by Stahylococcus spp., E. coli, Proteus spp., Steptococcus spp. and Pasteurella spp. in the order. 4. Antimicrobial drug susceptibility of the major organisms showed that all the isolates were susceptible to cephalothin, ampicillin, chloramphenicol and sulfamethoxazole / trimethoprim, but resistant to penicillin and streptomycin.