96-well microplate를 이용한 Trichophyton Rubrum의 항진균제 감수성검사

이무웅,김종철,최종수,김기홍 영남대학교 의과대학 1992 Journal of Yeungnam Medical Science Vol.9 No.2

저자들은 Granade와 Artis의 방법에 따라 96-well microplate와 24-well macroplate를 이용하여 T. rubrum 9주를 대상으로 경구용 항진균제인 ketoconazole과 itraconazole에 대한 MIC를 측정하여 실제 임상사용 가능성을 알아보고 배양온도, 배양용기의 크기, 배지의 종류를 달리하여 MIC에 영향을 줄 수 있는 요소를 점검하여 다음과 같은 결론을 얻었다. 1. 96-well microplate를 사용하여 25℃에서 배양시 균농도에 따른 판독시기의 차이는 높은 균농도(흡광도 2.0, 1.0)에서는 4일만에, 낮은 균농도(흡광도 0.5, 0.25)에서는 6-8일만에 판독할 수 있었고, MIC는 높은 균농도에서 높았으나 시간이 경과시 점차 차이가 줄어들었다. 2. 37℃와 25℃에서 각각 배양시 배양온도에 따른 MIC의 차이는 96-well microplate를 사용하여 37℃에서 배양시 ketoconazole에 대한 MIC는 0.006이하-0.04㎍/ml, itraconazole에 대한 MIC는 0.006이하-0.04㎍/ml였으며 25℃에서의 ketoconazole에 대한 MIC는 0.08-5.68㎍/ml, itraconazole에 대한 MIC는 0.06-0.71㎍/ml로 37℃에서의 MIC는 25℃에서의 MIC에 비해 현저히 낮았다. 3. 24-well microplate와 96-well microplate에서 각각 배양시 배양용기의 크기에 따른 판독시기는 96-well microplate액체배지에서는 4-6일로 24-well macroplate액체배지에서의 8-12일에 비해 판독 시기가 빨랐으나, MIC의 차이는 없었다. 4. 액체배지와 고체배지에서 배양시 배지종류에 따른 MIC의 차이는 액체배지를 함유한 24-well macroplate를 이용한 경우 ketoconazole에 대한 MIC는 0.006이하-5.68㎍/ml, itraconazole에 대한 MIC는 0.006이하-5.68㎍/ml로 고체배지에서의 MIC가 다소 높게 측정되었다. 5. 이상의 결과를 종합하여 볼때 96-well microplate를 사용하여, 흡광도 1.0의 균농도로 접종하여, 25℃에서 배양 후 5-6일째 육안으로 판독하는 것이 항진균제 감수성 검사를 빠르고 간편하게 실시 할 수 있는 방법이다. Various susceptibility tests have been used to determine minimal inhibition concentration(MIC) of dermatophytes. They have limitations to apply practically because they need long time to determine MIC. Authors examined MIC of T. rubrum to ketoconazole and itraconazole using 96-well microplate and 24-well macroplate by method of Granade and Artis and tried to check the possiblity of this method on clinical application. Nine strains of T. rubrum from patients with dermatophytosis were used. Evaluations of the factors affecting MIC were also tried. The results were as follows. 1. Effect of inoculation density on determination time and MIC: Determination of MIC were possible in 4th days after inoculation at higher inoculation density (aborbance 2.0, 1.0) compared to 6th days at lower inoculation density (absorbance 0.5, 0.25). 2. Effect of incubation temperature on MIC: When incubating at 37℃, MIC were below 0.006-0.04㎍/ml to ketokckonazole and below 0.006 -0.04㎍/ml to itraconazole while at 25℃ 0.08-5.68㎍/ml to ketoconazole and 0.006-0.71㎍/ml to itraconazole. Significant reduction of MIC was observed at 37℃ compared to 25℃. 3. Effect of container size on determination time and MIC : When incubating in 96-well microplate and 24-well macroplate, determination of MIC was possible in 4th to 6th days after inoculation in broth-containig 96-well microplate compared to 8th to 12th days in broth-containing 24-well macroplate. But no difference in MIC was observed between different container size. 4. Effect of media on MIC : When using broth as media. MIC were below 0.006- 5.68㎍/ml to ketoconazole, below 0.006-0.36㎍/ml to intraconzole in broth-containg 24-well macroplate. When using agar as media, MIC were below 0.006 - 5.68㎍/ml to ketoconzole, below 0.006-5.68㎍/ml to intraconzole in agar-containing 24-well macroplate. There was slight increase of MIC with agar media compared to broth media. 5. These findings confirm that determination of MIC of dermatophtes by method of Granade and Artis is fast and simple technique for antifungal susceptibility test.

다제내성 그람양성균에 대한 Linezolid(Zyvox^(�))의 시험관내 항균력 비교

박대원,정희진,엄중식,황병연,김성범,이재갑,이연주,정혜원,정성주,박재형,이진수,손장욱,김우주,김민자,박승철 대한감염학회 2003 감염과 화학요법 Vol.35 No.5

배경 : MRSA, VRE, VRSA같은 다제 내성 그람 양성균의 등장에 따라 glycopeptide를 대체할 새로운 항생제의 개발이 필요하게 되었고 결과적으로 새로운 항생제인 linezolid라는 항생제가 개발되었다. Linezolid는 이전의 항생제와는 다른 새로운 계열의 oxazolidinone으로 경구 이용률이 우수하다. 원내 및 원외감염의 중요한 원인균이 되고 있는 MRSA, VRE에 대한 적절한 경구용 항균제가 없는 국내에서 폐렴 및 피부 연조직 감염에서 경구용으로 사용해 볼 수 있는 약제이다. 본 연구에서는 고대 구로 병원에서 분리된 MRSA, VRE 등을 대상으로 다른 여러 항균제와 비교한 linezolid의 시험관내 항균력을 조사하고자 하였다. 재료 및 방법 : 연구대상은 1998년 1월부터 2000년 12월까지 본원에서 입원 및 외래를 통하여 피부 연조직 감염증 및 호흡기 감염증, 요로감염증으로 진단된 환자들의 가검물로부터 분리된 MRSA 60균주, VRE 43균주, PRSP 25균주를 액체배지 또는 한천배지 희석법을 통하여 linezolid 및 기타 항균제에 대한 최소발육억제농도를 구하였다. 결과 : 실험에 사용한 S. aureus는 모두 MRSA였고 이들은 linezolid에 대해 MIC_(90) 2㎍/㎖(MIC 범위 1-2㎍/㎖), Enterococcus spp는 모두 VRE로 linezolid의 MIC_(90)은 2㎍/㎖로 MIC 범위는 1-4㎍/㎖였다. 한 개의 균주에서 MIC 4㎍/㎖로 중등도 감수성을 보였으나 MIC breakpoint가 (8㎍/㎖인 내성균주는 없고 모두 감수성을 보였다. S. pneumoniae의 경우 penicillin 내성이었고, linezolid MIC_(90) 1㎍/㎖ (MIC 범위 0.5-1㎍/㎖)로 전부 감수성을 보였다. 결론 : Linezolid는 MRSA를 위시한 VRE, PRSP 등의 다제 내성 그람 양성균에 대하여 우수한 시험관내 항균력을 보임을 알 수 있었다. Background : The emergence of multi-drug resistant Gram-positive cocci, such as MRSA, VRE, and VRSA, necessitated to develop new antibiotics, which could replace the glycopeptide. As a result, a new antibiotics named linezolid was developed. Linezolid is different line of oxazolidinones with a good oral bioavailability, compared to other antibiotics. Since appropriate oral antibiotics are not presently available for MRSA, which is a major cause of nosocomial and community acquired infections, the introduction of linezolid will have favorable effect on treatment of infections such as pneumonia or skin infections. In this study, we investigated the antibiotic effect of linezolid on MRSA and VRE isolated from patients who were treated in Korea University Guro Hospital. Material and Methods : By using broth microdilution and agar dilution method we measured minimum inhibitory concentration (MIC) with sixty S. aureus, forty three Enterococcus spp., and twenty five S. pneumoniae isolates from patients who were diagnosed as skin, soft tissue, respiratory, and urinary infections in Korea University Guro Hospital from January, 1998 to December, 2002. Results : All of S. aureus used in this study were MRSA, and MIG_(90) of linezolid was below 2 ㎍/㎖ (MIC ranged between 1-2 ㎍/㎖). All of Enterococcus spp. were VRE, and had MIG_(90) of 2 ㎍/㎖ (MIC ranged between 1 to 4 ㎍/㎖). One of the VRE showed intermediate susceptibility with MIC of 4 ㎍/㎖. However, none was resistant with MIC breakpoint above 8 ㎍/㎖. All of S. pneumoniae were resistant to penicillin, but they were susceptible to linezolid with MICao of 1 ㎍/㎖(MIC range 0.5-1㎍/㎖). Conclusion : In conclusions, linezolid has an excellent in vitro antibiotic effect on multi-drug resistant Gram-positive cocci, such as MRSA, PRSP, and VRE.

Methicillin 내성 Staphylococcus epidermidis 검출을 위한 항생제감수성검사와 mecA 유전자검사의 비교

박종인,이정녀 대한임상병리학회 1998 대한임상병리학회지 Vol.18 No.3

Evaluation and Optimization of a Serum-based Minimum Inhibitory Concentration Assay to Caspofungin in Candida albicans Clinical Isolates

Young Bin Yoo,Sung-Soon Kim,Young Kwon Kim,Sunghyun Kim 대한의생명과학회 2016 Biomedical Science Letters Vol.22 No.4

In the present study, a serum-based minimum inhibitory concentration (MIC) testing to caspofungin was optimized and evaluated to solve the limitations of the conventional Clinical and Laboratory Standards Institute (CLSI) guideline-based antifungal agent MIC test and the usefulness of this testing for clinical application was determined. A total of 105 Candida albicans clinical isolates were used for measuring MIC to caspofungin. Results showed that growth characteristics were different according to types of serum and the mouse serum was the most suitable for this assay. In order to measure the optimal concentration of mouse serum, 0 to 100% mouse serum were added to the media during fungal culture. The optimal concentration of serum was 50% when consideration of antifungal agent administration and inoculum size, serum components and ease of hyphae separated, and the consideration of the degree of growth. In comparison of the usefulness between the conventional Alamar-modified broth microdilution MIC assay and 50% mouse serum-based MIC testing, the range of MIC80 of the Alamar-modified broth microdilution MIC assay was 0.13~2.0 μg/mL (SD ±0.42 μg/mL) and that of the 50% mouse serum-based MIC assay was 2.0~32.0 μg/mL (SD ±9.01 μg/mL). The range of MIC50 of the Alamar-modified broth microdilution MIC assay was 0.13~2.0 μg/mL (SD ±0.40 μg/mL) and that of the 50% mouse serum-based MIC assay was 1.0~16.0 μg/mL (SD ±2.36 μg/mL). The MICs of 50% mouse serum-based MIC testing was increased by up to 4 to 64 times than Alamar-modified broth microdilution MIC assay. In conclusion, a 50% mouse serum-based MIC assay was more useful for measuring MIC in Candida albicans clinical isolates than conventional colorimetric broth microdilution MIC testing.

Ciprofloxacin의 동물유래 병원세균에 대한 시험관내 항균효과시험

장경수,장치훈,김일택,박승춘,윤효인,전무형 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

In this study the antimicrobial spectrum and sensitivity of ciprofloxacin(CFX) against the major pathogenic bacteria isolated from the diseased poultry, pig, cattle in Korea were evaluated in comparison with morfloxacin(NFX), enrofloxacin(EFX), nalidixic acid(NA), gentamicin(GM), tetracycline(TC), erythromycin(EM), streptomycin(SM) and penicillin(PC). Increasing by paper disk diffusion test for total of 439 isolates from poultry, pig and cattle, CFX showed remarkably higher sensitivity(>83%) as compared with other drugs. When three quinolones such as CFX, NFX and NA were compared for the inhibition activity against 4 major pathogens, CFX induced significantly larger diameter of inhibition zone through all of the tested concentration than NFX and NA. As MICs of all drugs for 11 bacterial species isolated from poultry were measured, the MIC range of CFX was 0.125 - 40 ㎍/㎖ in Gram positives, ≤ 0.005 - 2.5 ㎍/㎖ in Gram negatives and 0.08 - 1.25 ㎍/㎖ with 12 isolates of Mycoplasma. MIC_50 and MIC_90 of CFX in these cases revealed consistently lower as compared with those of NFX, GM and PC. When the MICs of the drugs were tested with 11 bacterial species from the diseased pigs, MIC range of CFX was 0.05 - 3.5 ㎍/㎖ in Gram positives, ≤ 0.005 - 0.8 ㎍/㎖ with Gram negatives and 0.5 - 9.0 ㎍/㎖ with 11 isolates of Mycoplasma. MIC_50 and MIC_90 of CFX and NFX were remarkably lower than those of GM and PC. As MICs of CFX, NFX, GM and PC for 10 bacterial species isolated from cattle were tested, the MIC range of CFX was found 0.01 - 4.0 ㎍/㎖ in Gram positives, and ≤ 0.005 - 0.2 ㎍/㎖ in Gram negative bacteria. The MIC_50 and MIC_90 of CFX in cases of cattle appeared remarkably lower than those of the other drugs. CFX, as compared with the other drugs, showed invariably lower MIC_50 and MIC_90 in both of GRam positives and negatives. As MICs of CFX, NFX and PC for 12 reference bacteria were examined, MIC of CFX was 0.03 - 0.25 ㎍/㎖ that was much lower drug concentration than those of NFX(0.25 - 1.0 ㎍/㎖) and PC(0.5 - 16.0㎍/㎖).

E test를 이용한 그람음성 간균의 항균제 MIC측정

김재룡,김영재 啓明大學校 醫科大學 1997 계명의대학술지 Vol.16 No.2

For the adequate treatment to infectious disease, it is necessary to identify the etiologic organisms and evaluate the susceptibility to antimicrobial agents. As the patterns of resistance to various antimicrobial agents is persistently changing, the significance of the antimicrobial susceptibility test is enhanced more and more. We investigated that the usefulness of the E test(AB Biodisk, Solna, Sweden) for antimicrobial susceptibility test to gram negative bacilli. From December, 1996 to March, 1997,118 strains of gram negative bacilli isolated from Dongsan Medical Center, Keimyung University were investigated. The minimal inhibitory concentration(MIC) was estimated by E test. Antimicrobial agents used in E test were imipenem, ceftazidime, piperacillin/tazobactam, ciprofloxacin, gentamicin, ceftriaxone, amikacin, amoxicillin/clavulanic acid, aztreonam, cefotaxime, cefuroxime, and piperacillin. The criteria for antimicrobial susceptibillity was the guidelines of the National Committee for Clinical Laboratory Standards(1993). Among the 118 strains of gram negative bacilli analyzed by E test, A. baumanii, E. coli, P. aeruginosa and K. pneumoniae were each 20. 19. 26. and 9 strains. In the cases of A. baumanii, all strains were sensitive to imipenem and MIC range was 0.5-2㎍/mL, MIC50 WAS 0.5㎍/mL, and MI90 was 2 ㎍/mL. The half of the strains were sensitive to aztreonam, and the majority were resistant to most antimicrobial agents, except amikacin, aztreonam and imipenem. Among 19 strains of E. coli, all strains were sensitive to imipenem and MIc range was 0.13-2 ㎍/mL, MIC50 was 0.5㎍/mL, and MIC90 was 2 ㎍/mL. The majority were resistant to amoxicillin/clavulanic acid and piperacillin(9 and 12 strains). In the 26 strains of P. aeruginosa, 22 strains were sensitive to imipenem and each 2 strains were imtermediate and resistant to resistant to imipenem. MIC range to imipenem was 0.38-64 ㎍/mL, MIC50 was 2 ㎍/mL, and MIC90 was 8 ㎍/mL. Most of strains were sensitive to ceftazidime, piperacillin/tazobactam, ciprofloxacin, amikacin, aztreonam, and piperacillin, but most of strains were resistant to gentamicin, ceftriaxone, amoxicillin/clavulanic acid, cefotaxime, cefuroxime. The E test had been found to be valuable and to be a rapid, convenient and reliable method for estimating MIC and detecting high-resistance to various antimicrobial agents.

Upregulation and secretion of macrophage inhibitory cytokine-1 (MIC-1) in gastric cancers

Baek, K.E.,Yoon, S.R.,Kim, J.T.,Kim, K.S.,Kang, S.H.,Yang, Y.,Lim, J.S.,Choi, I.,Nam, M.S.,Yoon, M.,Lee, H.G. Elsevier Scientific Pub. Co 2009 Clinica chimica acta Vol.401 No.1

Background: Macrophage inhibitory cytokine-1 (MIC-1), a distant member of the transforming growth factor (TGF)-β superfamily, has been reported to be upregulated and secreted from several cancers. We examined MIC-1 expression and secretion in gastric cancers. Methods: MIC-1 mRNA and protein levels in cancer tissues and cell lines were analyzed by RT-PCR and Western blot. MIC-1 expression in cancer tissues and its secretion in serum were analyzed using immunohistochemistry and ELISA. Results: MIC-1 was significantly upregulated in gastric cancer tissues and cell lines. MIC-1 was secreted from gastric SNU620 cells and its levels in the serum of cancer patients were 10-fold higher than those of healthy controls. In addition, the staining of MIC-1 expression was strongly increased in metastatic gastric cancers. Conclusions: MIC-1 was obviously overexpressed in gastric cancers and MIC-1 secretion into blood may be useful for the prediction of gastric cancer progression.

In silico docking of methyl isocyanate (MIC) and its hydrolytic product (1, 3-dimethylurea) shows significant interaction with DNA Methyltransferase 1 suggests cancer risk in Bhopal-Gas-Tragedy survivors

Khan, Inbesat,Senthilkumar, Chinnu Sugavanam,Upadhyay, Nisha,Singh, Hemant,Sachdeva, Meenu,Jatawa, Suresh Kumar,Tiwari, Archana Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

DNA methyltransferase 1 (DNMT1) is a relatively large protein family responsible for maintenance of normal methylation, cell growth and survival in mammals. Toxic industrial chemical exposure associated methylation misregulation has been shown to have epigenetic influence. Such misregulation could effectively contribute to cancer development and progression. Methyl isocyanate (MIC) is a noxious industrial chemical used extensively in the production of carbamate pesticides. We here applied an in silico molecular docking approach to study the interaction of MIC with diverse domains of DNMT1, to predict cancer risk in the Bhopal population exposed to MIC during 1984. For the first time, we investigated the interaction of MIC and its hydrolytic product (1,3-dimethylurea) with DNMT1 interacting (such as DMAP1, RFTS, and CXXC) and catalytic (SAM, SAH, and Sinefungin) domains using computer simulations. The results of the present study showed a potential interaction of MIC and 1,3-dimethylurea with these domains. Obviously, strong binding of MIC with DNMT1 interrupting normal methylation will lead to epigenetic alterations in the exposed humans. We suggest therefore that the MIC-exposed individuals surviving after 1984 disaster have excess risk of cancer, which can be attributed to alterations in their epigenome. Our findings will help in better understanding the underlying epigenetic mechanisms in humans exposed to MIC.

A Family of Single-Stage Single-Switch PV MICs with Steep Conversion Gain

Ching-Ming Lai,Yi-Hung Liao 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

In this paper, a family of single-stage single-switch photovoltaic (PV) module integrated converters (MICs) with steep voltage conversion gain capability and galvanic isolation is presented. As an illustration, the new MIC topology based on the isolated-type single-ended primary-inductor converter (Sepic) with coupled inductor is analyzed and developed. Moreover, a fast maximum power point tracking (MPPT) strategy with linear current control is adapted in the proposed SEPIC-type PV MIC. Finally, a speciation of single-phase 150W prototype is constructed, and experimental results indeed verify the effectiveness of the proposed converter.

Fluoroquinolone계 항균제의 penicillin 내성 폐렴구균(Streptococcus pneumoniae)에 대한 항균력 비교

이광준,배송미,황규잠,이영희,김기상 대한화학요법학회 2002 대한화학요법학회지 Vol.20 No.3

목적 : 최근들어 penicillin 내성 폐렴구균의 급속한 증가와 전세계로의 확산은 심각한 문제를 야기하고 있다. 1990년대 들어 그람음성 세균뿐 아니라 그람 양성 세균에 대한 항균력이 향상된 많은 fluoroquinolones계 항균제의 개발에 힘입어 폐렴구균성 감염질환 치료시 사용이 증대되고 있으며 한편, 이와 더불어 이미 fluoroquinolone계 항균제에 대한 내성을 보이는 폐렴구균에 대한 보고가 증가하고 있는 실정이다. 이에 본 실험에서는 국내 임상 분리 폐렴구균 중 penicillin에 고도내성을 보이는 균주를 대상으로 하여 fluoroquinolones계 항균제에 대한 감수성 여부를 확인하고자 하였다. 방법 : 항균제 감수성 검사는 3% 말혈액이 첨가된 Mueller-Hinton broth를 사용한 액체배지 미량희석법을 이용하여 NCCLS에서 제시한 방법에 준하여 실시하였다. 결과 : MIC_90를 기준으로 하였을 때 본 실험에서 사용한 5가지의 fluoroquinolones계 한균제 중 gatifloxacin과 moxifloxacin(MIC_90, 0.5㎍/㎖)이 ciprofloxacin (MIC_90, 4㎍/㎖), levofloxacin (mic_90, 2㎍/㎖) sparfloxacin (MIC_90, 1㎍/㎖)에 비해 penicillin 내성 폐렴구균에 대한 항균력이 높게 나타났다. 결론 : 5가지의 fluoroquinolones계 항생제 중 최근들어 새로이 개발된 항생제인 moxifloxacin과 gatifloxacin이 ciprofloxacin, levofloxacin, sparfloxacin보다 폐렴구균에 대한 더 우수한 항균력을 가지고 있음을 확인하였다. 한편, 국내 페니실링 고도 내성 폐렴구균에서 fluoroquinolones에 대한 고도 내성을 보이는 균주의 출현은 fluoroquinolones 내성 균주의 급속한 증가와 확산에 대한 지속적인 감시와 대책 마련이 요구된다. Background : Recently the rapid increase and global spread of penicillin-resistant S. pneumoniae has become a serious problem. In the 1990s, a varisty of novel fluoroquinolones with enhanced activity against gram-positive bacteria have been developed and used for the treatment of pneumococcal infections. In such situations, the fluoroquinolone-resistance in S. pneumonaie has been reported from many countries. In this study, we compared the activity of ciprofloxacin, levofloxacin, sparfloxacin, gatifloxacin and moxifloxacin against 93 isolates of S. pneumoniae which were highly- resistant to penicillin (MIC 2~8㎍/㎖). methods : Antimicrobial susceptibilities were determined by the broth microdilution method in cation-adjusted Muller-Hinton broth supplemented with 3% lysed horse blood according to the guidelines of the National Committee for Laboratory Standards (NCCLS). Results : Based on MIC_90s, sparfloxacin and moxifloxacin were the most potent fluoroquinolone tested against penicillin-resistant S. pneumoniae and retained excellent activity comparable with ciprofloxacin and levofloxacin. The rank order of bactericidal activity was ciprofloxacin (least active)《 levofloxacin 〈 sparfloxacin 〈 gatifloxacin and moxifloxacin (most active). Conclusion : In this study, the newer fluoroquinolones (moxifloxacin, sparfloxacin)showed improved activity over that observed with ciprofloxacin, levofloxacin, and sparfloxacin. The emergence of highly resistance to fluoroquinolones among penicillin-resistant pneumococci in Korea call for continuous attention and strategies to prevent rapid increase and spread of these strains.