• 대한임상검사과학회지
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• 제45권1호
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• pp.16-20
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• 2013

Outbreaks of vancomycin-resistant enterococci (VRE) are being reported more frequently in many countries. While seven glycopeptide resistance genotypes have been described in Enterococci, vanA and vanB are the most common resistance genotypes. The aim of this study was to detect antibiotic susceptibilities of 23 Enterococcus faecium strains, which caused an outbreak in a University hospital by a disk diffusion test to investigate the presence of the species specific gene, and the resistant genotypes, vanA and vanB by duplex PCR. PCR for vanA and vanB was performed on 23 enterococci. Twenty three were identified as E. faecium and were tested positive for the vanA genotype. This study will report on the validation of a simple and accurate VRE detection method that can be easily incorporated into the daily routine of a clinical laboratory. Early detection of VRE strains, including those with susceptibility to vancomycin, is of paramount clinical importance as it allows rapid initiation of strict infection control practices, as well as the therapeutic guidance for confirmed infections. The PCR method developed in the present study is simple and reliable for the rapid characterization of VRE.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.568-584
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• 1994

Bacteria have been regarded as major etiolgic factors in root canal infections. Infected root canal flora from thirteen patients who had visited to conservative department of Wonkwang dental hospital were cultured on blood agar plates. Cultued microorganisms were isolated and identified with Gram stain and biochemical tests using Vitek Systems(BioMeriux, MO, USA); Antibiotic susceptibillity was performed with disk diffusion and broth microdilution using Vitek Systems. Gram positive cocci(65 %) were predominant, which were composed of 6 Streptococcus viridans group, 5 Staph. spp., and 4 Enterococcus faecium, in the isolatd 23 strains. Gram negative rods (26 %) were the next common bacteria, which were composed of 5 non - fermentative Gram negative rods, and 1 Enterobacter cloacae. Most strains of S. viridans group and E. faecium were susceptible to antibiotics including penicillin. But strains of Staphylococcus spp. and non - fermentative Gram negative rods showed marked resistance to antibiotics except tetrancyclin and cefotaxime. Most results between disk diffusion and microdilution were all agreed, but the results of non - fermentative Gram negative rods were susceptible to cefotaxime in disk diffusion method but resistant in microdilution.

• 미생물학회지
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• 제46권3호
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• pp.291-295
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• 2010

Streptococcus parauberis Z49가 생산하는 새로운 bacteriocin의 특성을 조사하고 수성 이상계를 사용하여 발효배양액에서 효율적으로 추출하였다. Nisin과 유사한 S. parauberis Z49의 bacteriocin은 $121^{\circ}C$에서 15 min 열처리해도 활성이 있었으며, 넓은 범위의 pH (pH 2-12)에서 안정하며, M. luteus, Lactobacillus sp., L. fermentum, E. faecium, L. monocytogenes, and P. fluorescens의 생육을 억제하였다. S. parauberis Z49의 발효배양액에 있는 bacteriocin을 간편하게 분리하기 위한 PEG 600/$Na_2SO_4$ 수성 이상계의 최적조건은 PEG 600 15%, $Na_2SO_4$ 30%, NaCl 8% 이었으며, bacteriocin은 PEG층에서 농축이 되었다.

• 한국식품위생안전성학회지
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• 제27권1호
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• pp.63-67
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• 2012

동물성 식품 유래 장구균의 항생제 내성은 내성균주 또는 내성 유전자가 먹이사슬을 통해 인체로 전달될 수 있다는 가능성 때문에 공중보건학적으로 중요하게 대두되고 있다. 본 연구는 원유 시료에서 분리된 장구균의 tetracycline에 대한 내성을 표현형 및 유전형 수준에서 분석하였다. 원유 시료에서 총 245주의 장구균을 분리하였으며 그 중 $E.$ $faecalis$ 가 199주로 전체의 81.2%를 차지 하였으며 그 외에 $E.$ $faecium$ 이 25주(10.2%), $E.$ $avium$ 이 7주(2.9%), $E.$ $durans$ 이 6주(2.5%), $E.$ $gallinarum$ 이 4주(1.6%), $E.$ $raffinosus$ 이 4주(1.6%)의 비율로 분리되었다. 분리 균주중 76.3%에 해당하는 187주가 tetracycline에 내성을 나타내었으며 내성균주의 83.4%에 해당하는 156주가 $tet$(M)을 26.7%에 해당하는 50주가 $tet$(S)를 16.1%에 해당하는 30주가 $tet$(L)을 3.2%에 해당하는 6주가 $tet$(M) + $tet$(L) + $tet$(S)의 3개의 유전자를 동시에 소유하고 있는 것으로 분석되었다.

• International journal of advanced smart convergence
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• 제11권4호
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• pp.227-239
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• 2022

Purpose: In our study, in order to find lactic acid bacteria (LAB) with multi-drug resistance to antibiotics, we isolated 140 strains from 15 types of kimchi commercially available in Korea and 20 types of Kimchi made at home from January to December in 2016, and investigated their H₂O₂ generating ability and multi-drug resistance to antibiotics. Methods: In order to observe the H₂O₂ generation ability of LAB, we performed the experiment with methods such as Rabe, Hillier, and Kang. To test the antibacterial susceptibility of LAB, we used the disc agar diffusion method using MRS agar (Difco, USA) according to the CLSI and WHO test methods. There are 18 types of antibiotic discs used. Results: Out of the total numbers of 140 strains, 6 strains of Ent. Faecium, 25 strains of L. plantarum, 1 strain of L. rhamnosus, 3 strains of L. sakei, 1 strain of L. acidophilus, 1 strains St. thermophilus, and 7 of unidentified strains generated H₂O₂. The antibiotic susceptibility of Ent. Faecium indicated SXT, OX, NA, and E; and the antibiotic susceptibility of L. plantarum indicated NA; and the antibiotic susceptibility of St. thermophilus indicated NA, CC, RA, CTT, CM, and P ; and the antibiotic susceptibility of L. rhamnosus indicated SXT, VA, NA and CTT; and the antibiotic susceptibility of 6 strains of L. sakei indicated SXT, OX, NOR, NA, CTT and CIP, all indicating antibiotic resistance. In the case of multi-drug resistance to antibiotics for 53 strains of L. antarum, 8-drug resistance was the most common with 25 strains, followed by 7-drug-resistant strains with 18 strains, 9-drug-resistant strains with 4 strains, 6-drug-resistant strains with 3 strains, 5-drug-resistant strains with 2 strains, and 17-drug-resistant strains with 1 strain. In the case of multi-drug resistance to antibiotics for Ent. Faecium 27 strains, 9-drug resistance was most commonly identified as 9 strains, 8-drug resistance was identified as 6 strains, 7- and 11 drug resistances were identified as 4 strains each, and 4- and 6-drug resistances were identified as 1 strain each. Conclusion: Ent. Faecium, L. plantarum, L. rhamnosus, L. sakei, and St. thermophilus, shown to have anantibacterial activity in previous studies on LAB and shown to have and H₂O₂ generating ability, antibiotic resistance and multi-drug resistance in this study, are expected to be able to play an excellent role for long-term inpatients to use as an alternative to antibiotics and to cope with emerging antibiotic resistance.

• 한국식품위생안전성학회지
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• 제25권2호
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• pp.122-128
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• 2010

2009년 4월부터 12월까지 서울시 보건환경연구원 미생물 관리팀에 의뢰된 냉동식품 100건을 대상으로 일반세균수, 대장균군수, 대장균과 장구균의 오염도를 조사였으며, 분리된 장구균을 대상으로 하여 항생제 감수성 검사를 실시하였다. 일반세균수는 평균 검출량이 $4.3{\times}10^4CFU/g$ 이고 대장균군수는 평균 검출량이 $4.3{\times}10^3CFU/g$ 이고 대장균은 100건 모두에서 불검출되어 0.0%의 검출률을 보였다. 100건의 검체 중 총 22건에서 장구균이 분리되었으며 이 가운데 12주는 E. faecium, 7주는 E. faecalis, 2주는 E. gallinarum, 1주는 E. hirae이었다. 분리균주의 항생제 내성률을 검사 한 결과, 내성을 나타내는 항생제들은 erythroycin, rifampin, teracycline ciprofloxacin, chlorampenicol, penicillin이며, vancomycin, ampicillin, gentamicin, strepomycin, linezolid에 대해서는 모두 감수성이었다. 또 22건의 분리 균주 중에서 2종 이상의 항생제에 다제 내성을 나타낸 균주가 15주나 되며 가장 많은 형태로는 6균주의 장구균에서 나타난 E-RA에 대한 것이었다.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1007-1014
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• 2015

Plectasin, the first defensin extracted from a fungus (the saprophytic ascomycete Pseudoplectania nigrella), is attractive as a prospective antimicrobial agent. The purpose of this study was to establish a bacterium-based production system and evaluate the antimicrobial activity of the resulting plectasin. A gene encoding plectasin, with the codon preference of Escherichia coli, was optimized based on its amino acid sequence, synthesized using genesplicing with overlap extension PCR, and inserted into the expression vector pGEX-4T-1. The fusion protein was expressed in the soluble fraction of E. coli and purified using glutathione Stransferase affinity chromatography. Plectasin was cleaved from the fusion protein with thrombin and purified by ultrafiltration. The purified plectasin showed strong, concentrationdependent antimicrobial activity against gram-positive bacteria, including antibiotic-resistant bacteria, especially penicillin-resistant Enterococcus faecium. This antimicrobial activity was equal to chemically synthesized plectasin and was maintained over a wide range of pH and temperatures. This soluble recombinant expression system in E. coli is effective for producing plectasin at a relatively lower cost, and higher purity and efficiency than prior systems, and might provide a foundation for developing a large-scale production system. Overall, plectasin shows potential as a novel, high-performance, and safe antibiotic for the treatment of refractory diseases caused by drug-resistant bacterial strains.

• 대한환경공학회지
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• 제36권10호
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• pp.672-678
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• 2014

본 연구는 음식물 쓰레기 내 질소농도에 따른 발효과정에서 수소생성 특성과 미생물의 군집변화를 살펴보았다. 음식물 쓰레기 내 질소의 함량이 200 mg/L일 때 가장 높은 수소생산 효율을 보여주었으며, 이 때 수소생산율은 83.43 mL/g dry wt biomass/hr이였다. 질소의 함량이 600 mg/L 이상이 되면 수소생산이 저해되는 것으로 나타났으며 수소생산량과 B/A ratio (Butric acid/Acetic acid)의 비례적 상관관계는 관찰되지 않았다. 16S rDNA의 PCR-DGGE결과 대부분 군집은 Clostridium sp. 미생물로 규명되었으며 수소생성에 기여도가 큰 미생물은 Enterococcus faecium partial, Klebsiella pneumoniae strain ND6, Enterobacter sp. NCCP-231, 그리고 Clostridium algidicarnis strain E107 등으로 판명되었다.

• Journal of Dairy Science and Biotechnology
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• 제29권2호
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• pp.81-85
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• 2011

Recently, antimicrobial resistance of microorganisms has been a major concern of its relation to food safety and national health, therefore, customer's needs to organic animal food is still increasing. In this study, we reviewed the usage of antimicrobials in animal farms and antimicrobial resistance of microorganisms isolated from organic dairy farm environments. The isolates from dairy farms were Acinetobacter sp., A. lwoffi, A. johnsonii, A. towneri, Aerococcus viridans, Aeromonas media, A. veronii, Bacillus pseudofirmus, B. pumilus, B. licheniformis, Corynebacterium glutamicum, Escherichia coli, Enterococcus faecium, Lysinibacillus fusiformis, Paenibacillus illinoisensis, Staphylococcus epidermidis, S. hominis, Streptococcus equinus, S. lutetiensis, and Saccharomyces cerevisiae. Indicator microorganisms isolated from organic dairy farms were tested for susceptibility to 20 types of antimicrobials. E. coli (ATCC 25922) isolated from dairy farm fence showed resistance to 8 types of antimicrobials, such as oxacillin, penicillin, vancomycin, etc., and E. faecium isolated from feces showed resistance to 9 types of antimicrobials, such as cephalothin, oxacillin, streptomycin, etc., respectively. However, these results showed less antimicrobial resistance compare with customary dairy farm.

• 한국응용곤충학회지
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• 제46권2호
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• pp.229-234
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• 2007

호박벌 일벌독의 성분과 생리활성을 규명하기 위하여 단백질 성분분석과 암세포 생육 저해 효능, 항균력을 검토하였다. 이차원단백질 분석을 통해 호박별의 일벌독은 63개의 단백질이 존재하는 것으로 확인되었으며, 가장 많은 함량을 보이는 3개의 단백질을 염기서열 분석하였다. 그러나 이들 성분은 아직 밝혀지지 않은 성분으로 판단되었다. 호박벌 일벌독의 암세포 (간암; Hep3B, 폐암; A549, 유방암; BT-20, 위암; AGS) 에 대한 생육 저해능은 시료 농도가 증가함에 따라 증가하는 경향을 보이며 100ng/ml에서 간암세포 (Hep3B) 에 대한 생육 저해능이 55%로 가장 높았다. 항균활성에 E. faecium 과 S. sonnei에 대하여 최소발육억제농도와 최소살균농도 모두 각각 0.256ug/ml 로 강한 항균활성을 나타내었으며, 그 외의 피검균에 대해서도 비교적 높은 활성을 보였다. 이상의 결과로부터 호박벌 일벌독의 성분은 다른 벌의 독성분과는 차이를 보이며, 그 생리활성에 있어 약리학적 이용이 가능할 것으로 판단되었다.