In vitro Evaluation of Antibiotic Lock Technique for the Treatment of Candida albicans, C. glabrata, and C. tropicalis Biofilms

고관수,이지영,송재훈,백경란 대한의학회 2010 Journal of Korean medical science Vol.25 No.12

Candidaemia associated with intravascular catheter-associated infections is of great concern due to the resulting high morbidity and mortality. The antibiotic lock technique (ALT) was previously introduced to treat catheter-associated bacterial infections without removal of catheter. So far, the efficacy of ALT against Candida infections has not been rigorously evaluated. We investigated in vitro activity of ALT against Candida biofilms formed by C. albicans, C. glabrata, and C. tropicalis using five antifungal agents (caspofungin, amphotericin B, itraconazole, fluconazole, and voriconazole). The effectiveness of antifungal treatment was assayed by monitoring viable cell counts after exposure to 1 mg/mL solutions of each antibiotic. Fluconazole, itraconazole, and voriconazole eliminated detectable viability in the biofilms of all Candida species within 7,10, and 14 days, respectively, while caspofungin and amphotericin B did not completely kill fungi in C. albicans and C. glabrata biofilms within 14 days. For C. tropicalis biofilm,caspofungin lock achieved eradication more rapidly than amphotericin B and three azoles. Our study suggests that azoles may be useful ALT agents in the treatment of catheterrelated candidemia.

Comparative Analysis of Growth-Phase-Dependent Gene Ex-pression in Virulent and Avirulent Streptococcus pneumoniae Using a High-Density DNA Microarray

고관수,Sulhee Park,오원섭,Ji-Yoeun Suh,TaeJeong Oh,Sungwhan Ahn,천종식,송재훈 한국분자세포생물학회 2006 Molecules and cells Vol.21 No.1

A report of 34 unrecorded bacterial species in Korea, belonging to the Actinobacteria

고관수,차창준,임완택,김승범,성치남,배진우,장광엽,조장천,조기성,이순동 국립생물자원관 2017 Journal of species research Vol.6 No.1

As a subset study to discover indigenous prokaryotic species in Korea in 2014, a total of 34 bacterial strains assigned to the phylum Actinobacteria were isolated from various environmental samples collected from activate sludge, biotite, freshwater, gut of marine organisms, mud flat, sediment, soil, spent mushroom compost and sea water. On the basis of high 16S rRNA gene sequence similarity and a tight phylogenetic association with the closest species, it was revealed that each strain was assigned to independent and previously described bacterial species, with the exception of one isolate. There is no official report that these 34 species included in the phylum Actinobacteria have been described in Korea: 6 species of 5 genera in the order Corynebacteriales, 1 species of 1 genus in the order Frankiales, 2 species of 2 genera in the Micromonosporales, 14 species of 10 genera in Micrococcales, 2 species of 2 genera in the Propionibacteriales, 1 species of 1 genus in the Pseudonocardiales, 4 species of 2 genera in the Streptomycetales, 2 species of 2 genera in the Streptosporangiales and 1 species of 1 genus in the Solirubrobacterales. Gram reaction, cell and colony morphology, pigmentation, physiological characteristics, isolation sources and strain IDs are described in the section of species description.

개별화 학습에 의한 중학생의 과학에 관한 태도 변화

고관수,강동식,박규은 濟州大學校 師範大學 科學敎育硏究所 1997 科學敎育 Vol.14 No.-

To see the possibility of Individualized Study, after analyzing the Unit, 'Force and Movement' I chose appropriate sub-subjects and made the plans of education directions and the materials of individualized study according to the respective sub-subjects. And then, I directed the first grade middle students naming the title 'The Attitude Change of the Middle Students by Individualized Study.' And using the individualized teaching method, teachers are required to prepare the materials which is considered about the level of the students. And it is needed for them to develop various materials themselves and direct their students to use their time efficiently and study science with interest according to their abilities.

氣溫變化가 쌀보리와 麥酒보리의 初期生育 및 葉特性에 미치는 影響

高官秀,吳現道,姜榮吉 濟州大學校 亞熱帶農業硏究所 1995 亞熱帶農業硏究 Vol.12 No.-

氣溫變化와 쌀보리와 麥酒보리의 初期生育 및 葉特性에 미치는 영향을 구명하기 위하여 쌀보리 3품종 (늘쌀보리, 새쌀보리, 향천과 1호)과 麥酒보리 3품종 (두산 8호, 사천 6호, 진광보리)을 공시하여 4, 8, 12, 16, 20, 24, 28℃의 생장상에서 4엽기까지 재배하여 분얼수, 건물중, 엽신장, 엽신폭, 엽록소를 조사한 결과를 요약하면 다음과 같다. 1. 늘쌀보리와 향천과 1호는 각각 16℃와 12℃에서 分蘖數가 個體當 3.1개로 가장 많았고 새쌀보리와 맥주보리 3품종은 모두 8℃에서 개체당 4.5개 내외로 가장 많았다. 2. 쌀보리 3품종의 개체당 乾物重은 16∼24℃에서 가장 무거웠으며 늘쌀보리는 1.5g 내외였고 새쌀보리와 향천과 1호는 2.0g 내외였다. 맥주보리 3품종은 16℃와 20℃에서 건물중이 가장 무거웠으며 사천 6호가 1.6g, 두산 8호와 진광보리가 모두 1.9g이었다. 3. 葉伸長은 모든 엽위에서 공시품종 모두 16∼24℃에서 가장 넓었고 새쌀보리, 향천과 1호, 맥주보리 3품종, 늘쌀보리 순으로 적었다. 4. 葉身幅은 모든 엽위에서 공시품종 모두 16∼24℃에서 가장 넓었고 새쌀보리, 향천과 1호, 맥주보리 3품종, 늘쌀보리 순으로 적었다. 5. 葉綠素 SPAD값은 8, 12℃에서 가장 컸던 늘쌀보리와 향천과 1호의 엽을 제외하고는 모든 엽위에서 4℃에서 가장 컸었다. Three naked (Nulssalbori, Saessalbori, Hyangcheongwa 1) and three malting barley cultivars (Doosan 8, Sacheon 6, Jinkwangbori) were grown at constant temperatures of 4, 8, 12, 16, 20, 24, and 28℃ through the fourth-leaf stage in growth chambers to determice the effects of air temperature on growth and leaf characteristics of naked and malting barley seedlings. The results obtained are summarized as follows: 1. The greatest number of tiller per plant at fourth-leaf stage was 3.1 at from 16 to 20℃ for Nussalbori and Hyangcheongwa 1 and about 4.5 at 8℃ for Saessalbori and three malting barley cultivars. 2. The above-ground dry weight per plant at fourth-leaf stage was heaviest (about 1.5g for Nulssalbori and about 2.0g for Saessalbori and Hyangcheongwa 1) at from 16 to 24℃ for three naked barley cultivars and was heaviest (abort 1. g for Sacheon 6 and 1.9g for Doosan 8 and Jinkwangbori) at 16 and 20℃ for three malting barley cultivars. 3. Blade length of the first four leaves was longest at about 24℃ regardless of cultivars and was smaller for Saessalbori, Hyangcheongwa 1, three malting barley cultivars, and Nulssalbori in order. 5. Chlorophyll SPAD values of the first four leaves were greatest at 4℃ except of the first leaf on Nulssalbori and Hyangcheongwa 1 which showed the highest values at 8 and 12℃.

Antimicrobial Resistance and Clones of Acinetobacter Species and Pseudomonas aeruginosa

이지영,고관수 대한미생물학회 2012 Journal of Bacteriology and Virology Vol.42 No.1

Antimicrobial resistance in bacteria is problematic in clinical settings and is a growing threat to public health. Multidrug-resistant and pandrug-resistant non-fermenters such as Acinetobacter spp. and Pseudomonas aeruginosa have recently emerged as a great concern worldwide. Particularly, the prevalence of carbapenem resistance in Acinetobacter spp. and P. aeruginosa is problematic, and emergence of polymyxin resistance is ominous. In this review, we discuss carbapenem and polymyxin resistance in Acinetobacter spp. and P. aeruginosa isolates and their major clones.

The First Case of Catheter-related Bloodstream Infection Caused by Nocardia farcinica

허상택,고관수,권기태,류성열,배인규,오원섭,송재훈,백경란 대한의학회 2010 Journal of Korean medical science Vol.25 No.11

Nocardia farcinica is an emerging pathogen in immunocompromised hosts. Even though several species of Nocardia have been reported as causative pathogens of catheter-related blood stream infections (CRBSI), CRBSI caused by N. farcinica has not been reported. A 70-yr-old man with a tunneled central venous catheter (CVC) for home parenteral nutrition was admitted with fever for two days. Norcardia species was isolated from the blood through CVC and peripheral bloods and identified to N. farcinica by 16S rRNA and rpoB gene sequence analyses. This report emphasizes the rapid and correct identification of causative agents in infectious diseases in the selection of antimicrobial agents and the consideration of catheter removal.

Effect of carbonyl cyanide 3-chlorophenylhydrazone (CCCP) on killing Acinetobacter baumannii by colistin

박영경,고관수 한국미생물학회 2015 The journal of microbiology Vol.53 No.1

We investigated the effect of cyanide 3-chlorophenylhydrazone(CCCP) and other efflux pump inhibitors (EPIs) on thecolistin susceptibility in Acinetobacter baumannii. While minimuminhibitory concentrations (MICs) of colistin in allcolistin-resistant strains decreased significantly with 25 μMof CCCP and 2,4-dinitrophenol (DNP), phenyl-arginine-β-naphthylamide (PAβN), and reserpine did not decrease thecolistin MICs. However, CCCP and DNP as well as PAβNand reserpine did not have a significant effect on the MICs ofthe other agents. Efflux pump gene expressions in colistinresistantstrains were not increased compared with those incolistin-susceptible strains. When only 5X MIC of colistin (5mg/L) was provided to a colistin-susceptible A. baumanniistrain, the bacterial cell number was reduced by 9 h after exposureto colistin, but regrowth was observed. When CCCPwas added to colistin, bacterial cells were completely killedafter 24 to 48 h of incubation, which was not due to the toxicityof CCCP itself. Colistin resistance in A. baumannii maynot be due to efflux pumps. Our present study suggests thatbacterial cells with reduced metabolic activity by CCCP aremore susceptible to colistin in A. baumannii. It may showthe possibility that combined therapy with colistin and otherantimicrobial agents could effective against A. baumanniiinfections.

Catheter-related Candidemia Caused by Candida haemulonii in a Patient in Long-term Hospital Care

김선용,고관수,문수연,이미숙,이미영,손준성 대한의학회 2011 Journal of Korean medical science Vol.26 No.2

Candida haemulonii, one of the non-albicans Candida species, is an emerging yeast pathogen that is known to be resistant to amphotericin B and other antifungal agents such as azoles. These anti-fungal agents have often been associated with clinical treatment failure, so no treatment regimen has been clearly established for invasive C. haemulonii infections. We investigated a catheter-related infection of C. haemulonii candidemia in an adult patient in long-term hospital care. In the early stages, the candidemia remained persistent despite treatment with fluconazole. However, after changing the antifungal agent to caspofungin, the candidemia was resolved. Fluconazole and amphotericin B are not reliable empirical antifungal agents for invasive C. haemulonii infections, as shown in previous case reports. An echinocandin such as caspofungin may be an appropriate empirical choice of antifungal agent for an invasive C. haemulonii infection.

아시아 지역 폐렴 구균의 항균제 내성 현황 및 변화 양상

정숙인,고관수,김연숙,오원섭,백경란,이남용,송재훈,김나영,손준성,기현균,서지연,장현하 대한감염학회 2004 Infection and Chemotherapy Vol.36 No.1

Background:Emergence of pneumococcal resistance became a global issue since 1990s. According to the ANSORP studies with clinical isolates and carriage isolates between 1996 and 1999, some Asian countries showed alarmingly high prevalence of resistance to penicillin and other antimicrobial agents. To investigate the changing trends of pneumococcal resistance, ANSORP study group has performed a multinational surveillance study with invasive pneumococcal isolates from Asian countries. Methods:All isolates from various invasive pneumococcal diseases were prospectively collected from 14 centers in 12 countries between November 1999 to August 2001. Broth microdilution tests with 16 antimicrobial agents were performed according to the NCCLS procedures. Serotyping was performed by means of Quelling reaction with use of group-specific antisera. Results:A total of 685 isolates were collected. Overall, 52.4% of invasive isolates from Asian countries were not susceptible to penicillin (intermediate (I), 22.9%; Resistant (R), 29.5%). Vietnam showed the highest prevalence of penicillin non-susceptibility (I 20.6%, R 71.4%) followed by Sri Lanka (I 71.4%, R 14.3%), Hong Kong (I 24.1%, R 76%) and Korea (I 9.7%, R 54.8%). China (I 19.8%, R 23.4%) and Malaysia (I 9.1%, R 29.5%) also showed remarkable increase in penicillin resistance compared with previous ANSORP data, which were less than 10%. Vietnam (92.1%), Taiwan (87.7%), Korea (80.6%), and Hong Kong (76.8%) showed high prevalence of erythromycin resistance. MIC90s for ciprofloxacin were 4 µg/mL (Hong Kong) and 2 µg/mL (11 Asian countries except Hong Kong), respectively. Conclusion:Compared with previous data from ANSORP studies, antimicrobial resistance among invasive pneumococcal isolates has markedly increased in Vietnam, Sri Lanka, Taiwan, China, and Malaysia. Continuous surveillance of pneumococcal resistance in Asia is strongly warranted. 목 적 : 1980 년대부터 페니실린을 비롯한 β-lactam 계열과 비 β-lactam 계열 항균제에 대한 폐렴구균의 항생제 내성이 급격하게 증가하여 국내 뿐 아니라 세계적인 문제로 대두되고 있다. ANSORP 에서는 아시아 지역에서 폐렴구균의 항균제 내성과 그 변화 추이, 내성의 기전 및 위험인자를 분석하고자 본 국제 공동 연구를 시행하였다.재료 및 방법 : 1999년 11월부터 2001년 8월까지 아시아 지역 12개국의 14개 기관에서 폐렴구균 감염증 환자의 임상 검체로 분리된 침습성 폐렴구균을 대상으로 액체배지 미량희석법을 이용하여 16개 항생제의 MIC를 구하였다. 위험인자의 분석을 위하여 폐렴구균 감염증 환자를 대상으로 의무기록지를 조사하였다. Quellung 반응을 통해 혈청형을 결정하였다. 결 과 : 총 685균주 중 52.4%가 페니실린에 대하여 비감수성(중등도 내성 22.9%, 내성 29.5%)을 보였고, 그 빈도는 베트남(92.1%), 스리랑카(85.7%), 홍콩(67.9%), 한국(64.5%)의 순이었다. Erythromycin에 대한 비감수성 비율은 베트남(92.1%), 대만(87.7%), 한국(80.6%), 홍콩(76.8%) 등에서 높게 나타났고, 베트남, 대만, 한국, 홍콩 등의 erythromycin의 MIC90이 32 g/mL를 넘는 고도내성을 보였다. 홍콩, 싱가포르, 대만, 인도에서는 fluoroquinolone에 대한 내성 균주가 출현하였다. 전체 균주 중 다제내성 균주의 비율은 47.7%였다. 혈청형은 19형과 23형이 가장 많았고, 그 외 6형, 14형 등이 있었다. 페니실린 비감수성 감염증의 위험인자로는 5세 미만 (OR=1.7; 95% CI, 1.2-2.4; P=0.002), 기관지폐질환 (OR=2.0; 95% CI, 1.3-3.1; P=0.003), 악성종양(OR= 2.3; 95% CI, 1.2-4.6; P=0.015), 스테로이드의 사용 (OR=2.8; 95% CI, 1.1-7.4; P=0.032)이 확인되었다.