항균제와 세균의 내성

용동은 생화학분자생물학회(구 한국생화학분자생물학회) 2013 생화학분자생물학회 소식 Vol.33 No.2

국내 5개 종합병원에서 분리된 주요 원내감염 세균에 대한 Cefepime의 시험관내 항균력

용동은,김현숙,박연준,홍석일,구선회,이경원,정윤섭 대한화학요법학회 2001 대한화학요법학회지 Vol.19 No.3

목적 : Enterobacter, Citrobacter, Serratia, A. baumannii 및 P. aeruginosa 등의 원내 감염균은 AmpC β-lactamase 과량 생산으로 인하여 여러 가지 β-lactamase 항균제에 내성인 균주가 많다. Cefepime은 제 4세대 cephalosporin으로 AmpC β-lactamase 과량 생산균에 대한 항균력이 우수하고, oxacillin 감수성 포도구균과 penicillin 내성 S. pneumoniae에도 항균력 있는 것으로 알려져 있다. 그러나 국내분리균주에서 cefepime의 항균력은 시험된 바 적다. 본 연구에서는 우리나라 병원에서 분리되는 원내감염 세균에 대한 cefepime의 항균력을 다른 광범위 β-lactamase 항균제의 항균력과 비교하고자 하였다. 방법 : 1999년 전국 5개 병원에서 분리한 원내 감염세균에 대한 항균제 감수성을 각각의 병원에서 Etest strip (AB Biodisk, Solna, Sweden)으로 시험하였다. 시험 균주는 균종별로 약 10주씩이었고, 대상균종은 E. coli, Klebsiella spp., C. freundii, Enterobacter spp., Serratia spp., Indole-positive Proteeae, Acinetobacter spp., P. aeruginosa, oxacillin-suspectible S. aureus, and oxacillin-suspectible coagulase-negative Staphylococcus이었다. 시험 항균제는 cefepime, cefpirome, ceftazidime, ceftriaxone, imipenem, oxacillin 그리고 piperacillin-tazobactam이었다. 결과 : 총 407주 그람음성 간균에서 cefepime의 MIC_(90)는 E. coli에 대하여 0.75㎍/mL, Klebsiella spp. 12㎍/mL, C. freundii 2㎍/mL 및 E. cloacae 48㎍/mL로서 imipenem을 제외한 다른 시험항균제의 MIC_(90)보다 낮았다. 전체 균종의 감수성율은 imipenem 89%, cefepime 78%, cefpirome 74%, ceftazidime 66%, piperacillin-tazobactam 65% 및 ceftriaxone 51%이었다. Oxacilin 감수성 포도구균의 감수성율은 cefepime, cefpirome 및 imipenem에 대해 100%이었다. 결론 : Cefepime의 원내감염 세균에 대한 시험관내 항균력은 imipenem을 제외한 다른 광범위 항균제보다 우수하여, 이 항균제는 원내감염증 환자의 치료에 유용할 것으로 판단되었다. Background : Common nosocomial pathogens such as Pseudomonas aeruginosa, Acinetobacter baumannii, and species of Enterobacter, Citrobacter, and Serratia, are often resistant to various β-lactam antibiotics by Amp C β-lactamase hyperproduction. Cefepime, a fourth generation cephalosporin, has been reported to have higher activity against AmpC β-lactamase-producing strains. It is also reported to be active against oxacillin-susceptible S. aureus, and penicillin-resistant S. pneumoniae. However, few studies were reported with Korean isolates. The purpose of this study was to compare the in vitro activities of cefepime and other broad-spectrum β-lactam antibiotics against nosocomial pathogens isolated in Korean Hospitals. Methods: In 1999, each of five participating hospitals in Korea tested the antimicrobial susceptibility for nosocomial pathogens using Etest strip. The number of isolates tested were about ten per species, which were E. coli, Klebsiella spp., C. freundii, Enterobacter spp., Serratia spp., Indole-positive Proteeae, Acinetobacter spp., P. aeruginosa, oxacillin-susceptible S. aureus, and oxacillin-susceptible coagulase-negative Staphylococcus. Antimicrobials used were cefepime, cefpirome, ceftazidime, ceftriaxone, imipenem, oxacillin and piperacillin-tazobactam. Results: A total of 407 isolates were tested. The MIC_(90s) of cefepime were 0.75 ㎍/mL for E. coli, 12 ㎍/mL for Klebsiella spp., 2 ㎍/mL for C. freundii, and 48 ㎍/mL for Enterobacter spp., which were generally lower than those of other antibiotics except imipenem. The following were the susceptibility rates of gram-negative bacilli to various antimicrobials, respectively: imipenem, 89%; cefepime, 78%; cefpirome, 74%; ceftazidime, 66%; piperacillin-tazobactam, 65% and ceftriaxone, 51%. To cefepime, cefpirome and imipenem, 100% of oxacillin-susceptible S. aureus were susceptible. Conclusion: The higher in vitro activities of cefepime than other broad-spectrum β-lactam antibiotics except imipenem suggests cefepime is useful for the treatment of patients with nosocomial infections.

국내 대학병원 환자의 호흡기 검체에서 분리된 세균에 대한 Gatifloxacin의 시험관내 항균력

용동은,김명숙,김신영,이경원,김성규,정윤섭,이일섭 대한감염학회 2004 감염과 화학요법 Vol.36 No.2

목적 : 새로 개발된 8-methoxyquinolone인 gatifloxacin은 호흡기 감염균을 포함한 광범위 세균에 항균력을 보인다. 본 연구에서 저자들은 gatifloxacin과 비교약제의 시험관내 항균력을 최근 우리나라 환자의 호흡기에서 분리된 세균에 대하여 시험하였다. 방법 : 본 저자들은 2000-2001년에 국내 8개 대학병원에서 만성 하부기도 감염증이 급성 악화된 환자의 호흡기 검체에서 분리된 세균 49주와 연세의대 병원 환자의 호흡기 검체에서 분리된 병원균 108균주를 대상으로 하였다. 항균제 최소억제 농도는 NCCLS 한천희석법으로 시험하였다. 결과 : Streptococcus pneumoniae에 대한 gatifloxacin의 MIC_(90)는 1㎍/mL로서 ciprofloxacin과 levofloxacin의 MIC_(90)보다 각각 8배와 2배 낮았다. Haemophilus influenzae와 Moraxella (Branhamella) catarrhalis는 각각 gatifloxacin ≤0.06㎍/mL와 ≤0.25㎍/mL에서 억제되었고 시험한 fluoroquinolones제에 모두 감수성이었다. Klebsiella pneumoniae에 대한 gatifloxacin의 MIC_(90)는 0.06㎍/mL으로 levofloxacin과 moxifloxacin의 MIC_(90)보다 2배 낮았다. 결론 : Gatifloxacin은 국내 환자의 호흡기병원에서 분리된 세균인 S. pneumoniae, H. influenzae 및 M. (B.) catarhalis에 대한 시험관내 항균력이 우수하였다. Background : Gatifloxacin, a new 8-methoxyquinolone, has a broad-spectrum activity with expanded potency against respiratory pathogens. In this study, we examined the in vitro activity of gatifloxacin and comparators against recently isolated bacteria from respiratory specimens of patients in Korean hospitals. Methods : Forty-nine isolates were from respiratory specimens of patients with acute exacerbations of chronic lower respiratory infections in eight university hospitals and 108 isolates were from respiratory specimens from patients of Yonsei University Hospital. Minimum inhibitory concentrations (MICs) were determined by NCCLS agar dilution method. Results : MIC_(90) of gatifloxacin for Streptococcus pneumoniae was 1 ㎍/mL, which was 8-fold and 2-fold lower than those of ciprofloxacin and levofloxacin, respectively. All strains of Haemophilus influenzae and Moraxella (Branhamella) catarrhalis were inhibited by ≤0.06 ㎍/mL and ≤0.25 ㎍/mL of gatifloxacin, respectively, and were susceptible to all fluoroquinolones tested. MIC_(90) of gatifloxacin for Klebsiella pneumoniae was 0.06 ㎍/mL, which was 2-fold lower than those of levofloxacin and moxifloxacin. Conclusion : Gatifloxacin is highly active against S. pneumoniae, H. influenzae and M. (B.) catarrhalis isolated from respiratory specimens of patients of university hospitals in Korea.

향균제가 없는 환경에서 항균제 감수성 그람음성 간균 공존의 내성 그람음성 간균에 대한 영향

용동은,최응칠,이경원,염종화,정윤섭 대한감염학회 2002 Infection and Chemotherapy Vol.34 No.1

국내 대학병원 환자의 호흡기 검체에서 분리된 세균에 대한 Gatifloxacin의 시험관내 항균력

용동은,이경원,김성규,정윤섭,이일섭,김명숙,김신영 대한감염학회 2004 Infection and Chemotherapy Vol.36 No.2

Background:Gatifloxacin, a new 8-methoxyquinolone, has a broad-spectrum activity with expanded potency against respiratory pathogens. In this study, we examined the in vitro activity of gatifloxacin and comparators against recently isolated bacteria from respiratory specimens of patients in Korean hospitals. Methods:Forty-nine isolates were from respiratory specimens of patients with acute exacerbations of chronic lower respiratory infections in eight university hospitals and 108 isolates were from respiratory specimens from patients of Yonsei University Hospital. Minimum inhibitory concentrations (MICs) were determined by NCCLS agar dilution method. Results:MIC90 of gatifloxacin for Streptococcus pneumoniae was 1 µg/mL, which was 8-fold and 2-fold lower than those of ciprofloxacin and levofloxacin, respectively. All strains of Haemophilus influenzae and Moraxella (Branhamella) catarrhalis were inhibited by ≤0.06 µg/mL and ≤0.25 µg/mL of gatifloxacin, respectively, and were susceptible to all fluoroquinolones tested. MIC90 of gatifloxacin for Klebsiella pneumoniae was 0.06 µg/mL, which was 2-fold lower than those of levofloxacin and moxifloxacin. Conclusion:Gatifloxacin is highly active against S. pneumoniae, H. influenzae and M. (B.) catarrhalis isolated from respiratory specimens of patients of university hospitals in Korea. 목 적 : 새로 개발된 8-methoxyquinolone인 gatifloxacin은 호흡기 감염균을 포함한 광범위 세균에 항균력을 보인다. 본 연구에서 저자들은 gatifloxacin과 비교약제의 시험관내 항균력을 최근 우리나라 환자의 호흡기에서 분리된 세균에 대하여 시험하였다. 방 법 : 본 저자들은 2000-2001년에 국내 8개 대학병원에서 만성 하부기도 감염증이 급성 악화된 환자의 호흡기 검체에서 분리된 세균 49주와 연세의대 병원 환자의 호흡기 검체에서 분리된 병원균 108균주를 대상으로 하였다. 항균제 최소억제 농도는 NCCLS 한천희석법으로 시험하였다. 결 과 : Streptococcus pneumoniae에 대한 gatifloxacin의 MIC90는 1 g/mL로서 ciprofloxacin과 levofloxacin의 MIC90보다 각각 8배와 2배 낮았다. Haemophilus influenzae와 Moraxella (Branhamella) catarrhalis는 각각 gatifloxacin ≤0.06 g/mL와 ≤0.25 g/mL에서 억제되었고 시험한 fluoroquinolones제에 모두 감수성이었다. Klebsiella pneumoniae에 대한 gatifloxacin의 MIC90는 0.06 g/mL으로 levofloxacin과 moxifloxacin의 MIC90보다 2배 낮았다. 결 론:Gatifloxacin은 국내 환자의 호흡기병원에서 분리된 세균인 S. pneumoniae, H. influenzae 및 M. (B.) catarrhalis에 대한 시험관내 항균력이 우수하였다.

2019 신종 코로나바이러스 검사 진단

용동은 대한의료관련감염관리학회 2020 의료관련감염관리 Vol.25 No.1

Metallo-β-lactamase 생성 그람음성 간균

용동은 대한임상미생물학회 2009 Annals of clinical microbiology Vol.12 No.3

Among gram-negative bacteria, rate of antibiotic resistance has been increasing. As a result, carbapenem is now considered as a last resort of therapeutic regimens for gram-negative bacterial infections. The choice of antibiotics has been impeded by the spread of organisms producing metallo-β-lactamases (MBL), which can confer resistance to nearly all β-lactams. MBLs have extremely diverse structures and are carried by various organisms including human pathogens. This review will focus on the classification and current status of MBL reported in Korea.

지속적 배양결과 감시를 통한 Cladosporium Species 가유행 검출

용동은,유수헌,김명숙,정혜선,이양순,정석훈,이경원,정윤섭 대한의료관련감염관리학회 2010 의료관련감염관리 Vol.15 No.1

Background: Cladosporium spp. are dematiaceous fungi that are commonly isolated from indoor and outdoor environments, including hospital air. This fungus is rarely pathogenic to humans, but has been reported to cause infections of the skin and toenails, as well as sinusitis and pulmonary infections. The monitoring of culture results was conducted to identify the outbreak of an unknown black fungal infection between January and March 2006 in a University hospital, and infection control activity was performed to identify the cause of the outbreak. Methods: An epidemiological investigation of 22 patients with infections caused by an unknown black fungus was conducted. Microscopic examination and molecular analysis on the internal transcript spacer (ITS) region was performed to identify the black fungus. To detect the source of contamination, a culture of environmental specimens was performed, and then, disinfection of the laboratory was implemented. Results: The patients with black fungi belonged to various departments and wards. No symptoms of fungal infection were recognized on the basis of the survey. The black fungus was identified as Cladosporium spp. on the basis of morphological features and ITS region sequencing. Culturing of environmental specimens was performed in the laboratory. Black fungi were isolated from a specimen from a rack and had the same morphological features with Cladosporium spp. from clinical specimens. After the rack was autoclaved, Cladosporium spp. from clinical specimens was no longer isolated. Conclusion: Epidemiological investigation, microscopic examination, and molecular analysis revealed that the sudden increase in the isolation rate of Cladosporium spp. from clinical specimens was the result of a pseudo-outbreak caused by the contamination of a rack. To our knowledge, this is the first report of a pseudo-outbreak of Cladosporium spp. Continuous monitoring of culture results is important to avoid unnecessary labor for nosocomial infection control.

16S rRNA 및 Internal Transcribed Spacer 염기서열 분석법을 이용한 세균 및 진균 동정

용동은,정석훈,이경원,박윤희,신희봉,김창기,노경호,염종화 대한임상미생물학회 2010 Annals of clinical microbiology Vol.13 No.1

Background: Accurate and rapid identification of pathogens is one of the most important tasks of the clinical microbiology laboratory, and, in cases of rare pathogens, the identification is difficult and time-consuming upon the use of conventional methods alone. Herein, we will report our molecular work involving the identification of bacteria and fungi. Methods: Sixty bacterial isolates had been collected from November 2004 to May 2007, and 15 fungal isolates had been collected from September 2005 to May 2007. Species identifications were performed using sequence analyses of the 16S rRNA region of bacteria and the internal transcribed spacer (ITS) region of fungi. The data were compared with those of GenBank (http://www.ncbi.nlm.nih.gov/) or EMBL (http://www.ebi.ac.uk/embl/). Results: Sixty bacterial isolates included: 23 isolates with genus information (group 1), 17 isolates (group 2) that were too fastidious for genus or species identification,16 isolates (group 3) with results from identification kits having low confidence, and 4 isolates (group 4) with odd antibiograms according to the species. In 58 of 60 isolates, identification of the genus or species could be obtained using molecular genetic methods. Thirty-eight isolates (63%) and 20(33%) of 58 isolates could be identified at the species and genus levels, repectively. Among the total of 15 fungal isolates, 11 (73%) and 4 (27%) isolates were identified at the species and genus levels,respectively. Conclusion: 16S rRNA and ITS sequencing analyses are very useful for identifying the species or genus of a pathogenic microorganism in the clinical microbiology laboratory. (Korean J Clin Microbiol 2010;13:34-39)

화학발광자동면역분석기 Vitros ECi®를 이용한 TSH, Free Triiodothyronine, Free Thyroxine 및 Estradiol 검사 평가

용동은,선영규,이건수,김정호,권오헌 대한임상병리학회 2002 대한임상병리학회지 Vol.22 No.2

배경: 임상 검사실에서는 자동화 및 간편성의 요구가 커지는 한편 정확도, 민감도 및 직선성이 우수한 검사 방법이 요구된다. 저자들은 방사선면 역측정법(방사면역검사법)을 대체할 만한 화학발광 면역검사법을 적용한 Vitros ECi®Immunodiagnostic System에 의한 TSH, FT4, FT3 및 estradiol 검사를 평가하였다.<br>방법: TSH, free triiodothyronine (FT3), free thyroxine (FT4) 및 estradiol (E2)을 평가 대상으로 하였다. NCCLS기준에 의한 정밀도를 측정하였고, Elecsys 2010 및 방사면역검사법을 기준으로 분석하였다. TSH와 E2 에 대하여는 기능적 민감도와 직선성을 측정하였다. FT4 및 FT3에 대해서는 배수 희석법에 의한 유리 호르몬 검정을 실시하였다.<br> 결과: 정밀도는 네 종목 모두 우수하였고, TSH 및 E2의 기능적 민감도는 각각 0.007㎖μ/ℓ 및 87 p㏖/ℓ이었다.TSH는 최소 78 ㎖μ/㎖까지, E2는 최소 7,700 p㏖/ℓ까지 직선성이 유지되었다. 유리 호르몬 검정에서도 FT4와 FT3 각각 > 8.5p㏖/ℓ > 4 p㏖/ℓ로 감소되지 않았다. 참고방법과 상관성비교에서 TSH, FT4 및 FT3는 기울기 0.83-1.41의 비례오차를 보였고, E2의 경우 기울기 1.48-1.79의 비례오차가 있었다.<br> 결론: Vitros ECi®에 의한 TSH, FT3, FT4 및 E2 검사는 우수한 성능을 보여서, 기존의 방사면역검사법의 단점을 극복할수 있는 방법으로 평가되었다. Background: The analytical performance of the Vitros ECi® Immunodiagnostic System on the thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and estradiol (E2) assays, which are based on electrochemical luminescence to replace the radioimmunoassay was evaluated.<br> Methods: The precision as measured by the NCCLS protocol and a comparison of the method were done for each TSH, FT3, FT4, and E2 assay. The functional sensitivity and linearity tests were performed for both TSH and E2. The free hormone validity test was performed for both the FT3 and FT4.<br> Results: All four analytes showed an acceptable precision. The functional sensitivities of TSH and E2 were 0.007 ㎖μ/ℓ, and 87 p㏖/ℓ, respectively. TSH and E2 showed excellent linearity up to 78 ㎖μ/㎖, and up to 7,700 p㏖/ℓ, respectively. The free hormone validity test showed acceptable results demonstrating accurate free hormone determination. The E2 showed a significant proportional bias requiring an adjustment of the reference range, However, the other analytes showed good agreement with a slight proportional bias.<br> Conclusions: The TSH, FT3, FT4, and E2 assay by Vitros ECi® exhibited excellent performance overcoming the drawbacks of a conventional radioimmunoassay.