• Tuberculosis and Respiratory Diseases
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• 제60권2호
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• pp.228-234
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• 2006

연구배경 : A. baumannii는 중환자실내의 원내감염의 중요 원인균으로 인식되고 있으며, 원내 폐렴, 요로 감염증, 균혈증 등을 일으킨다. 현재 이 균의 다약제 내성이 문제되고 있으며 특히 carbapenem에 내성을 보이고 있는 것이 가장 큰 문제가 되고 있다. 이 연구의 목적은 중환자실 환자의 객담에서 배양된 A. baumannii 중 carbapenem 내성군과 감수성군 두 군으로 나누어 위험인자를 알아보고 임상적 특징을 비교 및 분석하는 것이다. 방 법 : 2003년 1월 1일부터 2003년 12월 31일까지 강원대학교 중환자실에 입원한 성인 환자들 중 객담 배양 검사상 A. baumannii가 한 번이라도 검출된 환자들을 대상으로 챠트 기록을 통한 후향적 분석을 하였다. 위험인자로 연령, 성별, APACHE II score, 동반질환, 사용한 항생제, 재원기간, 중환자실 재원기간, Clinical Pulmonary Infection Score, 인공호흡기 여부를 평가하였다. 결 과 : 총 49명으로 A. baumannii에 대한 carbapenem 감수성군은 23명 내성군은 26명이었다. 단일변량분석에서는 신장 질환, 이전의 aminoglycoside 및 carbapenem 사용력이 통계적인 의미를 보였고 다변량분석에서는 이전의 aminoglycoside 사용력은 carbapenem 내성과 음의 상관관계를(p=0.026; OR, 0.18; CI, 0.04 to 0.82), 이전의 carbapenem 사용력은 carbapenem 내성과 양의 상관관계를(p=0.024; OR, 8.17; CI 1.32 to 50.68) 보여주었다. 사망률에서는 양 군에서 유의한 차이를 보이지 않았다(30 vs 42%, P=0.39). 결 론 : Carbapenem 내성 A. baumannii의 발생의 위험인자로 이전의 aminoglycoside와 carbapenem 사용력이 있으며 carbapenem 사용 시 A. baumannii의 carbapenem 내성정도가 증가함을 볼 수 있다.

• 대한의생명과학회지
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• 제27권2호
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• pp.59-68
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• 2021

Multidrug-resistant strain of Acinetobacter baumannii (MDRAB) is an emerging pathogen in health care facilities, preventing MDRAB is a public health concern. We conducted this experiment on a clinical isolate of A. baumannii with two main goals: the role of the efflux pump system in the stress provision of carbapenem and the response to the transcription level of the efflux pump gene. A total of 34 strains of A. baumannii was isolated from the Yangsan Hospital of Pusan National University. First, when we compared and observed the expression of the efflux pump gene and antibacterial resistance to carbapenem, a strong correlation was observed between carbapenem resistance and overexpression of adeB (P=0.0056). Second, a correlation between the efflux pump and concentration gradient and tolerance to carbapenem stress at the AdeABC efflux pump genes transcription level was confirmed. Our results revealed that the expression of the AdeABC efflux pump is an important resistance determinant in obtaining antibiotic resistance of the carbapenem group in A. baumannii.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1154-1162
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• 2015

The emergence of carbapenem resistance among Pseudomonas aeruginosa is an increasing problem in many parts of the world. In particular, metallo-$\beta$-lactamases (MBLs) and AmpC $\beta$lactamases are responsible for high-level resistance to carbapenem and cephalosporin. We studied the diversity and frequency of $\beta$-lactamases and characterized chromosomal AmpC $\beta$lactamase from carbapenem-resistant P. aeruginosa isolates. Sixty-one carbapenem-resistant P. aeruginosa isolates were collected from patients in a tertiary hospital in Daejeon, Korea, from January 2011 to June 2014. Minimum inhibitory concentrations (MICs) of four antimicrobial agents were determined using the agar-dilution method. Polymerase chain reaction and sequencing were used to identify the various $\beta$-lactamase genes, class 1 integrons, and chromosomally encoded and plasmid-mediated ampC genes. In addition, the epidemiological relationship was investigated by multilocus sequence typing. Among 61 carbapenem-resistant P. aeruginosa isolates, 25 isolates (41.0%) were MBL producers. Additionally, 30 isolates producing PDC (Pseudomonas-derived cephalosporinase)-2 were highly resistant to ceftazidime (MIC₅₀ = $256{\mu}g/ml$) and cefepime (MIC₅₀ = $256{\mu}g/ml$). Of all the PDC variants, 25 isolates harboring MBL genes showed high levels of cephalosporin and carbapenem resistance, whereas 36 isolates that did not harbor MBL genes revealed relatively low-level resistance (ceftazidime, p < 0.001; cefepime, p < 0.001; imipenem, p = 0.003; meropenem, p < 0.001). The coexistence of MBLs and AmpC $\beta$-lactamases suggests that these may be important contributing factors for cephalosporin and carbapenem resistance. Therefore, efficient detection and intervention to control drug resistance are necessary to prevent the emergence of P. aeruginosa possessing this combination of $\beta$-lactamases.

• 대한임상검사과학회지
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• 제50권4호
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• pp.406-413
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• 2018

최근 P. aeruginosa의 carbapenem에 대한 내성은 전 세계적으로 증가하고 있는 실정이다. 특히 $metallo-{\beta}-lactamases$ (MBLs)는 carbapenem의 고도 내성에 관여하고 있는 것으로 보고되고 있다. 한편, Sequence type 235 (ST235)는 다제내성 클론으로써 국제적으로 보고되고 있으며, IMP-6와 VIM-2 유전자의 확산에도 관여하는 것으로 알려져 있다. 본 연구에서는 2008년 3월부터 2014년 6월까지, 대전지역의 3차 병원에서 분리된 carbapenem 내성 P. aeruginosa에서 MBL 유전자를 분석하고 이에 대한 역학관계를 조사하고자 하였다. 항균제 감수성 양상은 디스크 확산법으로 확인하였고, MBL 유전자의 분석을 위해 PCR과 염기서열분석을 수행하였다. 더불어, 역학 관계를 조사하기 위해 multilocus sequence typing (MLST)를 실시하였다. 110 균주의 carbapenem 내성 P. aeruginosa 중, 32균주(29.1%)가 MBL를 생성하였고, IMP-6 (29균주, 90.6%)가 주요하게 확인되었다. VIM-2는 3균주(9.4%)에서 확인되었으며, 모두 ST357로 확인되었다. IMP-6를 생성하는 P. aeruginosa는 모두 다제내성을 보였고, ST235로 확인되었다. ST235 (55균주, 50.0%)는 가장 높은 비율로 확인된 클론이며 7년 동안 지속적으로 확인되었다. 이러한 다제내성 ST235의 확산을 방지하기 위해, carbapenem의 과도한 사용을 제한하고, 지속적으로 모니터링하는 전략이 개발되어야 할 것으로 사료된다.

• 의료관련감염관리
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• 제21권2호
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• pp.50-56
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• 2016

ESBL을 생성하는 균주에 의한 요로 감염에서 카바페넴 계열 이외의 항생제를 사용할 수 있는 지를 후향적으로 평가한 연구이다. 만약 in vitro 결과에서 감수성이 있다면 사용이 가능하다는 결과이나 환자의 중증도가 높다면 실패할 수 있음을 강조하였다. 이번 연구 결과를 바탕으로 전향적 연구를 기대해 본다.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1768-1772
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• 2008

CW-270031 is a novel synthesized carbapenem antibiotic with a broad antimicrobial activity. Carbapenem antibiotics are well known for their nephrotoxicity. In this study, we evaluated the nephrotoxicity potential of this compound in rabbits, which are known for being more sensitive than other animals to renal insult. CW-270031 was administered to NZW male rabbits via an ear vein (200 mg/kg, single injection). Blood samples were collected on 2, 3, and 4 days after treatment. Urea nitrogen and creatinine in plasma were quantified. Four days after the treatment, all animals were autopsied and histopathological examinations were performed on their kidneys, revealing that cephaloridine and imipenem were highly nephrotoxic, and cefazolin had mild renal toxicity, whereas CW-270031 as well as meropenem and tienam had no toxicity to the kidney. The present findings suggest that CW-270031 is a potential carbapenem antibiotic with no nephrotoxicity.

• 약학회지
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• 제39권3호
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• pp.215-222
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• 1995

The in vitro antibacterial activities of new carbapenem. CRB 529, 535, 538, 545 and 550 with meropenem and imipenem were compared. CRB 529. 535, 538, 545 and 550 proved to have a broad an tibacterial spectrum. Its in vitro activity against standard 20 strains was almost the same as that of imipenem and slightly higher than that of meropenem. However. against clinical isolated P. aeruginosa, CRB 529, 535, 538, 545 and 550 showed significantly higher activity than imipenem, and also CRB 529, 535, 538, 545 and 550 showed almost the same activity than imipenem and meropenem against 82 clinical isolated strains including S. aureus (MRSA), S. aureus (MSSA), E. faecalis, E. facium, E. coli, P. aeruginosa, K. pneumonia, P. mirabiris, P. stuartii, M. morganii, C. freundii, E. cloacae, S. marcescens and A. calcoaceticus var. anitratus. The stability of CRB 529, 535, 538, 545 and 550 against porcine renal dehydropeptidase-I(DHP-1) was 10 folds higher than that of imipenem and was 3 folds higher than that of meropenem.

• Pediatric Infection and Vaccine
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• 제18권1호
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• pp.97-102
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• 2011

Acinetobactor baumanii 는 기회 감염균으로 carbapenem의 사용이 증가하면서 MDRAB와 같은 내성균으로 출현하고 있다. 저자들은 경희의료원에서 carbapenem을 투약받지 않았더라도 집중치료실에 장기간 입원하여 기관삽관과 인공호흡기 치료를 받거나 침습적인 수술을 받아 도관을 유지하는 환아에서 MDRAB가 동정되었다는 것을 확인하였다. carbapenem을 사용하지 않았더라도 장기간 집중치료실에 입원할 것으로 예상되는 환자들에게 원내전파를 통한 감염을 최소화하기 위하여 원내감염관리에 최선을 다해야 할 것이기에 이상의 증례를 통하여 보고한다.

• Tuberculosis and Respiratory Diseases
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• 제72권4호
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• pp.360-366
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• 2012

Background: Carbapenem-resistance is rapidly evolving among the pathogenic microbes in intensive care units (ICUs). This study aimed to determine annual trend of carbapenem-resistance in the ICU for 4 years, since the opening of a university-affiliated hospital in South Korea. Methods: From 2005 to 2008, microbial samples from consecutive 6,772 patients were screened in the ICU. Three hundred and ninety-seven patients (5.9%) and their first isolates of carbapenem-resistant pathogens were analyzed. Results: The percentage of patients infected with carbapenem-resistant organisms increased constantly during the initial three years (2.3% in 2005, 6.2% in 2006, 7.8% in 2007), then it declined to 6.5% in 2008. Acute Physiology and Chronic Health Evaluation (APACHE) III score at admission was $58.0{\pm}23.5$, the median length of the ICU stay was 37 days, and the mortality rate was 37.5%. The sampling sites were endotracheal suction (67%), catheterized urine (17%), wound (6%) and others (10%). Bacteria with carbapenem-resistance were Pseudomonas aeruginosa (247 isolates, 62%), Acinetobacter baumannii (117 isolates, 30%), Enterobacteriaceae (12 isolates, 3%), and others (21, 5%). Of note, peak isolation of carbapenem-resistant microorganisms in medical ICU was followed by the same epidemic at surgical ICU. Conclusion: Taken together, carbapenem-resistant pathogens are of growing concern in the ICU.

• 한국미생물·생명공학회지
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• 제50권4호
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• pp.584-591
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• 2022

Identifying carbapenem-resistant Enterobacteriaceae (CRE) is necessary to prevent nosocomial CRE infection outbreaks. Here, a rapid identification method with reduced enrichment time was developed without compromising accuracy. A total of 49 rectal swabs requested for CRE screening at the Department of Diagnostic Medicine at Hospital B in Busan, Korea, were included in this study. Specimens were inoculated on MacConkey and CHROMID Carba media either directly or following enrichment for 3, 6, and 24 h in 100 μl trypticase soy broth containing an ertapenem disk. The enriched cultures were further inoculated on CHROMID Carba or MacConkey media containing an ertapenem disk. In total, 19 CRE and 5 carbapenem-intermediate Enterobacteriaceae isolates were obtained from the 49 swabs. Among the 19 CRE isolates, carbapenemase-producing Enterobacteriaceae constituted 13 strains. Moreover, of the 19 CRE isolates, 16 (81.25%) and 17 (88.24%) were identified from the direct cultures on MacConkey and CHROMID Carba media, respectively. After 3 h of enrichment, the proportions of the CRE identified in the media were: MacConkey medium, 16/19 (81.25%); CHROMID Carba medium, 17/19 (88.24%); and MacConkey medium containing an ertapenem disk, 17/19 (88.24%). The detection rates after 6 h of enrichment were the same for all three media (19/19 strains, 100%), whereas those after 24 h of enrichment were 21, 22, and 24 strains, respectively, but included false positives. These findings suggest that a 6-h enrichment before inoculation on the CHROMID Carba medium is optimal for the rapid and accurate detection of CRE in clinical samples.