• 한국수소및신에너지학회논문집
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• 제16권4호
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• pp.324-333
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• 2005

The kinetics of external hydrogen embrittlememt is considered. The equation of the crack growth rate (CGR) is derived from modification of the model developed by Wilkinson and Vitek. After calculation of hydrogen pressure build-up in the void, the effect of the internal hydrogen pressure on the void growth is added. The CGR is expressed by two terms. One is the term dependent on the critical stress, which is exactly same as Wilkinson and Vitek. The other is term dependent on the pressure of the hydrogen in void.

• Journal of Microbiology
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• 제40권2호
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• pp.170-172
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• 2002

To determine the occurrence of vancomycin-resistant Enterococci in a raw milk sample, raw milk samples were examined for a period of 6 months. Enterococci were isolated directly from Enterococcal selective agar plates supplemented with 2 mg of vancomycin per liter, Nineteen strains were selected and identified by applying the Vitek system. To determine resistance patterns, 19 isolates were tested with vancomycin and teicoplanin. Vancomycin-resistant Enterococci were genotyped by using a PCR analysis and 5 out of 19 isolates were of the VanC type.

• Journal of Microbiology and Biotechnology
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• 제16권6호
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• pp.889-895
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• 2006

To investigate the antibiotic-resistant patterns and the gene types of extended-spectrum $\beta$-lactamase (ESBL)-producing Klebsiella pneumoniae, we collected 226 Klebsiella pneumoniae strains from three general hospitals with more than 500 beds in Busan, Korea from September 2004 to October 2005, The minimum inhibitory concentration (MIC) of antibiotics was measured using the Gram-negative susceptibility (GNS) cards of Vitek (Vitek system, Hazelwood Inc., MO, U.S.A.). Of the 226 K, pneumoniae isolates, 65 ESBL-producing K. pneumoniae strains were detected by the Vitek system and confirmed by the double-disk synergy test. TEM (Temoniera) type, SHV (sulfhydryl variable) type, and CTX-M (cefotaxime) type genes were detected by polymerase chain reaction. All 65 K. pneumoniae strains were resistant to ampicillin, cefazolin, cefepime, ceftriaxone, and aztreonam, and 83.0% of the organisms were resistant to ampicillin/sulbactam, 66.1% to tobramycin, 67.6% to piperacillin/tazobactam, 61.5% to ciprofloxacin, and 47.6% to trimethoprim/sulfamethoxazole, and 43.0% to gentamicin. TEM-type ESBLs (TEM-1 type, -52 type) were found in 64.6% (42 of 65) of the isolates, SHV-type ESBLs (SHV-2a type, -12 type, -28 type) in 70.7% (46 of 65) of isolates, and CTX-M-type ESBLS (CTX-M-15 type) in 45% (29 of 65) of isolates. Of the 65 ESBL-producing K. pneumoniae strains, two strains were found to harbor blaSHV-28, which were detected in Korea for the first time. Therefore, more investigation and research on SHV-28 are needed in order to prevent the ESBL type-producing K. pneumoniae from spreading resistance to oxyimino cephalosporin antibiotics.

• 대한의생명과학회지
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• 제12권3호
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• pp.267-274
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• 2006

Klebsiella pneumoniae is the leading cause of nasocomial infection and the most commonly isolated from clinical specimens. $Extended-spectrum-{\beta}-lactamase$ (ESBL) producing K. pneumoniae infection was associated with a significantly longer duration of hospital stay and greater hospital charges. The purpose of this study is to investigate the antibiotic resistant patterns and the DNA fingerprint types of extended-spectrum ${\beta}-lactamase$ (ESBL) producing K. pneumoniae. 223K. pneumoniae strains were collected from three general hospitals with more than 500 beds in Busan, Korea from September 2004 to October 2005. The minimum inhibitory concentration (MIC) of antibiotics was measured using the Gram negative susceptibility (GNS) cards of VITEK (Vitek system, Hazelwood Inc., MO). Random amplified polymorphic DNA method was used to detect DNA fingerprint of the organisms. Of the 226 K. pneumoniae isolates 65 ESBL-producing K. pneumoniae strains were detected by the Vitek system and confirmed by the double-disk synergy test. All the 65K. pneumoniae strains were resistant cefazolin, cefepime, ceftriaxone and aztreonam, and 83.0% of the organisms were resistant to ampicillin/sulbactam, 66.1% to tobramycin, 67.6% to piperacillin/tazobactam, 61.5% to ciprofloxacin, and 47.6% to trimethoprim/sulfamethoxazole and 43.0% to gentamicin. The RAPD patterns were distincted as 10 types by three random 10-mer primers (208, 272, 277). Among ten type patterns, three types (Ic, IIb, IIIe) were remarkably represented at patient of internal department, nerve surgery department, general surgery department, and neonatal room. These results indicate that RAPD can be useful for DNA of strains typing in the epidemiological investigations. Therefore more investigation are needed in order to prevent the ESBL type-producing K. pneumoniae from spreading resistance to oxyimino cephalosphorin antibiotics.

• 한국축산시설환경학회지
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• 제21권3호
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• pp.83-92
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• 2015

An attempt to produce more pigs in limited spaces inevitably generalized concentrated feeding operation (CFO). As concentrated pig production practice expanded, concerns on environmental issues grow concurrently. Since odor is the concerned most among those, we attempted to develop means to tackle odor emission from livestock operations. Previously, we excavated few microorganisms from pig manure and, one of them, Bacillus licheniformis was particularly useful to handle odor problem. In this study, we conducted our investigation to further characterize Bacillus licheniformis. Strain identification was conducted using Vitek 2 compact, and the optimal temperature and pH conditions to growth B. licheniformis were searched for by analyzing turbidity on O.D 600 nm. Results of this study can be summarized as these, (1) it was re-verified that the bacterial strain that purified from pig manure was, in fact, Bacillus licheniformis, (2) the bacterial growth was highest when the temperature was kept at $30^{\circ}C$, also (3) growth rate was dependent on media pH as it was high at neutral (6, 7 and 8) but dropped when it was diverged from neutral (4, 5, 9 and 10), and (4) regarding ammonia removal efficiency, B. licheniformis recorded 64% effectiveness after 48 h incubation and reached its highest (80%) at 72 h.

• Safety and Health at Work
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• 제11권4호
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• pp.517-525
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• 2020

Background: The study was planned to show the status of indoor microorganisms and the status of the reduction device in the military dog clinic. Methods: Airborne microbes were analyzed according to the number of daily patient canines. For identification of bacteria, sampled bacteria was identified using VITEK^®2 and molecular method. The status of indoor microorganisms according to the operation of the ventilation system was analyzed. Results: Airborne bacteria and fungi concentrations were 1000.6 ± 800.7 CFU/m³ and 324.7 ± 245.8 CFU/m³. In the analysis using automated identification system, based on fluorescence biochemical test, VITEK^®2, mainly human pathogenic bacteria were identified. The three most frequently isolated genera were Kocuria (26.6%), Staphylococcus (24.48%), and Granulicatella (12.7%). The results analyzed by molecular method were detected in the order of Kocuria (22.6%), followed by Macrococcus (18.1%), Glutamicibacter (11.1%), and so on. When the ventilation system was operated appropriately, the airborne bacteria and fungi level were significantly decreased. Conclusion: Airborne bacteria in the clinic tend to increase with the number of canines. Human pathogenic bacteria were mainly detected in VITEK^®2, and relatively various bacteria were detected in molecular analysis. A decrease in the level of bacteria and fungi was observed with proper operation of the ventilation system.

• 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.

• 대한임상검사과학회지
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• 제51권2호
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• pp.260-264
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• 2019

84세 여성이 항문까지 욕창이 번져 응급실에 내원하였다. 그녀는 근처의 요양기관에서 전원되었고, 입원시 소변 도뇨관을 달고 있었으며 열은 없었다. 그람염색에서 많은 수의 포도상구균과 >25의 호중구 (${\times}1000$배 렌즈)가 관찰되었다. 24시간 배양한 혈액한천배지에서 용혈이 없는 점액성의 집락이 관찰되었으며 배양 48시간에는 점액성이 더욱 확대되었다. India ink로 염색하여 협막의 모습을 관찰하였으며, 카타라제 양성, 라텍스법 혈액응고효소 음성, 시험관법 혈액응고효소 음성소견을 보였다. Vitek-2와 질량분석기인 Vitek MS V-3 IVD에서 S. aureus로 나타났으며, 16S rRNA 유전자 염기서열 분석 및 Multilocus sequencing typing (MLST)에서 S. aureus로 표준균주인 ATCC 29213과 99.9% 일치를 보였다. 본 증례는 용혈성이 없고, 점액성이 강하며, 라텍스법 혈액응고효소 음성, 시험관법 혈액응고효소 음성소견을 보이는 MRSA를 동정하여 이를 보고한다.

• 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.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 춘계학술발표논문집
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• pp.579-582
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• 2009

본 연구는 혈액에서 분리되는 미생물의 균종과 항균제 감수성 검사 결과 양상은 환자의 일반적 특성에 따라 다르므로 혈액배양 결과를 분석한 자료는 감염증 환자의 경험적 치료를 위한 중요한 근거가 되고, 특히 ESBL을 생성하는 균주의 경우 항균제의 사용과도 밀접한 관련이 있어 이 연구를 하게 되었다. 대상은 중부지역 일개대학병원의 입원 및 외래환자의 2004-2006년 혈액배양 결과와 항균제 내성 결과를 분석하였다. 혈액배양은 Bact/Alert 3D (North Carolina, Durham, USA)를 이용하여 성인에서는 Bact/Alert S（Aerobic)(Biomerieux Brazil S.A)와 Bact/Alert SN（Anaerobic)(Biomerieux Brazil S.A) 배지를 사용하였고, 소아에서는 Bact/Alert PF (Biomerieux Brazil S.A)배지를 사용하여 5일간 배양하였고, 항균제 감수성 검사는 자동화 동정 및 감수성 장비인 VITEK (BioMerieux vitek. Hazelwood. Missori. USA)을 이용하였다.