영남 지역에서 분리된 폐렴구균의 항균제 감수성

정윤성,신정환,장철훈,손한철,정석훈,이용성,김병국,이채훈,김성률 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

배경 : Penicillin 내성 폐렴구균의 분리율이 증가하고 있으며 내성균에 의한 중증 감염은 치료에 대한 반응이 나쁘다. 이에 본 연구에서는 영남지역에 있는 병원들의 임상 검체에서 분리된 폐렴구균들 대상으로 항균제 감수성 검사를 실시하여 폐렴구균에 의한 감염증의 적절한 치료에 도움을 주고자 하였다. 방법 : 영남지역의 5개 병원에서 분리된 폐렴구균 61균주를 대상으로 디스크 확산법 또는 한천희석법으로 감수성 검사를 실시하였다. 결과 : Oxacillin 디스크를 이용한 penicillin 감수성 검사에서는 내성율이 91.2%였고 한천희석법에서는 감수성 9.8%, 중등도 및 고도 내성 각각 37.7%, 52.5%였다. 디스크 확산법에서 6개의 감수성 균주 중 한 개를 찾아내는데 실패하여 16.7%의 major error를 나타내었다. Ceftriaxone은 감수성 45.9%, 중등도 및 고도 내성 각각 42.6%, 11.5%였다. Penicillin과 ceftriaxone에 모두 내성인 경우는 전체의 54.1%, penicillin 내성 균주의 60.0%였다. 디스크 확산법에 의한 감수성 검사에서 vancomycin은 모두 감수성이었고, chloramphenicol 21%, erythromycin 82%, trimethoprim/sulfamethoxazole 79%, tetracycline 84%의 내성을 보였고 다약제 내성율은 59%였다. 결론 : 영남 지역 임상 검체에서 분리된 폐렴구균의 항균제 내성 비율이 매우 높아서 폐렴구균에 의한 중증 감염증의 적절한 치료를 위해서는 penicillin 이외의 여러 항균제에 대한 감수성 검사가 반드시 필요하다고 생각한다. Background : The resistance rate of Streptococcus pneumoniae to penicillin has been rapidly increasing worldwide, and treatment failures coupled with severe infections due to penicillin-resistant S. pnemoniae have been reported. In this study, we evaluated antimicrobial susceptibilities of S. pnemoniae isolated from clinical specimens in the Southeastern area of Korea. Methods: A total of 61 pneumococcal isolates obtained from patients who visited or were admitted to 5 hospitals in the Southeastern area of Korea during the period 1997 to 1998. Antimicrobial susceptibility tests for 61 isolates were performed using disk diffusion or agar dilution methods. Results : Penicillin susceptibility tests showed that 91.8% and 90.2% of isolates were not susceptible to penicillin by oxacillin disk diffusion and dilution methods, respectively. Moderate and high level resistance rate to penicillin were 37.7% and 52.5%, respectively. Using the oxacillin disk diffusion method, we failed to find one among 6 penicillin-susceptible isolates, with 16.7% major error. Moderate and high level resistance rate to ceftriaxone were 42.6% and 11.5%, respectively. The concomitant resistance rate to penicillin and ceftriaxone was 54.1% of the total and 60.0% of penicillm-resislant isolates. Resistance rates of the isolates to vancomycin, chloramphenicol, erythromycin, trimethoprim/sulfamethoxazole, and tetracycline were 0%, 21%,82%, 79%, and 84%, respectively. Multidrug-resistance to three or more classes of antimicrobials was 59.0%. Conclusion: In this study, we revealed that extremely high resistance rate of 5. pneumoniae to many antimicrobial agents in Southeastern area of Korea. Therefore, accurate susceptibility tests to penicillin, 3rd generation cephalosporin and other antimicrobial agents are highly recommended for adequate treatment of severe pneumococcal infections.

An Electrochemical Enzyme Immunochip Based on Capacitance Measurement for the Detection of IgG

Yi, Seung-Jae,Choi, Ji-Hye,Kim, Hwa-Jung,Chang, Seung-Cheol,Park, Deog-Su,Kim, Kyung-Chun,Chang, Chulhun L. Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.4

This study describes the development of an electrochemical array immunochip for the detection of IgG. Interdigitated immunochip platforms were fabricated by sputtering gold on a glass wafer by using MEMS process and then were coated with Eudragit S100, an enteric polymer, forming an insulating layer over the working area of immunochips. The breakdown of the polymer layer was exemplified by the catalytic action of urease which, in the presence of urea, caused an alkaline pH change. This subsequently caused an increase of the double layer capacitance of the underlying electrode. Used in conjunction with a competitive immunoassay format, this allowed the ratio of initial to final electrode capacitance to be directly linked with the concentration of analyte, i.e. IgG. Responses to IgG could be detected at IgG concentration as low as $250\;ngmL^{-1}$ and showed good linearity up to IgG concentration as high as $20\;{\mu}gmL^{-1}$.

통증사진에 대한 반복적 통증평가가 의대생의 인지적 공감과 정서적 공감에 미치는 영향

이상권(Sang-Kwon Lee),천경주(Kyung-Ju chun),장철훈(Chulhun L. Chang),김성수(Sung-Soo Kim) 한국콘텐츠학회 2017 한국콘텐츠학회논문지 Vol.17 No.1

본 연구의 목적은 의대생들의 공감능력 수준에 따른 타인의 통증인지 수준 평가와 공감능력의 변화를 파악하여 짧은 시간 내에 공감능력이 낮은 의대생들의 공감능력을 높일 수 있도록 하는 공감교육 컴퓨터 프로그램 개발에 있다. 총 145명 대상자들의 공감능력을 고집단과 저집단으로 나누었다. 또한, 타인의 통증인지 수준 평가를 측정하기 위해 개발한 컴퓨터 프로그램인 ‘Pain Assessment Computer Program(PACP)’을 사용하였다. PACP 수행 후 공감 고집단은 인지적 공감능력만 유의미하게 증가한 반면, 공감 저집단은 인지적 공감능력과 정서적 공감능력 모두 증가하였다. PACP 수행과정에서 두 집단 모두 인지적 공감능력이 공통적으로 증가하였는데 이는 대상자들이 인지적 요소를 우선적으로 사용함으로써 인지적 공감이 상승된 것으로 보이며, ‘인지적 노력’에 따른 인지적 공감능력의 향상에 긍정적인 영향을 준 것으로 판단된다. 이처럼 PACP는 짧은 시간 내에 공감능력이 낮은 의대생들의 공감능력을 향상시키는 보조 수단으로서 활용할 수 있을 것이다. To develop a more efficient computer-based empathy program that enables medical students to increase their empathy ;evels, and to test its applicability to medical students. We developed PACP (the Pain Assessment Computer Program) for measurement of medical students’ levels of recognition of another’s pain. An empathy questionnaire was administered to 145 medical students before and after the PACP. In the high empathy group, the scores for cognitive empathy increased significantly after completion of the PACP, while affective empathy scores showed no significant change. In contrast, in the low empathy group, both cognitive and affective empathy scores increased significantly after the PACP. The PACP effectively increased cognitive empathy for the high empathy group, and increased both cognitive and affective empathy, particularly for the low empathy group. Given the fact that existing empathy education programs are time-consuming and costly, and the demand for more efficient empathy education is high, the PACP as a useful tool can be applicable to medical students, particularly those with low empathy in order to enhance their empathic abilities within a short period of time.

결핵균 약제감수성 검사의 비용효율성에 관한 다기관 연구

정석훈,이대동,최재철,김선주,신정환,정윤성,이은엽,오승환,배길한,장철훈 대한감염학회 2005 감염과 화학요법 Vol.37 No.1

목적 : 우리나라에서의 결핵균 감수성 검사는 검출 균주의 일부에서만 시행되고 있다. 본 연구에서는 모든 검출 균주들에 대해서 감수성검사를 실시하면서, 진료에 필요한 결과를 충분히 제공하고 경제적이면서 현실적인 감수성검사 방안을 제시하고자 한다. 재료 및 방법 : 5개 대학병원에서 일정기간 연속적으로 의뢰된 502균주의 감수성 결과를 분석하였다. 검사결과의 해석 및 2차 약제 감수성검사의 필요성은 NCCLS approved standard M24-A의 권고 기준에 따라 판단하였다. 결과 : 최소한 1가지 이상의 약제에 내성을 보인 경우는 초치료 환자의 10% (38/363), 재치료 환자의 61%(85/139)였으며, 다약제 내성을 보인 경우는 초치료 환자의 3% (11/363), 재치료 환자의 44% (61/139)였다. NCCLS 권고에 따라 2차 약제에 대한 감수성 검사를 시행하지 않아도 되는 경우는 초치료 환자의 96%, 재치료환자의 47%였다. 결론 : 초치료 환자는 95%에서 1차 약제에 대한 검사만으로 충분하므로 필요한 경우에만 2차 약제를 추가로 검사하고 재치료 환자에서는 1, 2차 약제를 동시에 검사할 필요가 있을 것으로 생각한다. Background : The anti-mycobacterial susceptibility test is performed on only a small percentage of clinical isolates in Korea. The aim of this study is to propose an anti-mycobacterial susceptibility testing scheme, which is not only economic and practical but also fully informative to physicians. Materials and Methods : The anti-mycobacterial susceptibility test results of 502 strains, isolated from five university-affiliated hospitals, were analysed. The interpretation of the results and the need for second-line drug susceptibility test were judged according to the recommendation of NCCLS M24-A guidelines. Results : The isolates from 10% (38/363) of treatment-navie patients and 61% (85/139) of retreatment patients showed resistance to at least one of the anti-mycobactial agents; 3% (11/363) and 44% (61/139) of isolates from each group were multi-drug resistant. According to the recommendation by NCCLS, the percentage of patients not needing the susceptibility test results for second-line drugs were 96% for treatment-naive and 47% for re-treatment patients. Conclusion : Since the susceptibility test against first-line drug is sufficient for 95% of treatment-navie patients with tuberculosis patients, susceptibility test against second-line drugs may be performed only when it is necessary. As for the re-treatment patients with tuberculosis, susceptibility test for both first-line and second-line drugs should be performed simultaneously.

Isolation and Antimicrobial Susceptibility of Nontuberculous Mycobacteria in a Tertiary Hospital in Korea, 2016 to 2020

Chang Chulhun L.,Oh Seung-Hwan,Jeon Doosoo,Keun Ju Kim 대한결핵및호흡기학회 2023 Tuberculosis and Respiratory Diseases Vol.86 No.1

Background: There is a global increase in isolation of nontuberculous mycobacteria (NTM). The aim of the study was to analyze longitudinal trends of NTM identification and pattern of antimicrobial susceptibility testing.Methods: NTM recovery rates, distribution of NTM species identification, and antimicrobial susceptibility pattern of NTM at Pusan National University Yangsan Hospital between January 2016 and December 2020 were retrospectively analyzed.Results: A total of 52,456 specimens from 21,264 patients were submitted for mycobacterial culture, of which 2,521 from 1,410 patients were NTM positive over five years (January 2016 to December 2020). NTM isolation showed an increasing trend from 2016 to 2020 (p<0.001, test for trend) mainly caused by <i>Mycobacterium avium</i> complex. The vast majority of <i>M. avium</i> complex were susceptible to key agents clarithromycin and amikacin. For <i>Mycobacterium kansasii</i>, resistance to rifampin and clarithromycin is rare. Amikacin was the most effective drug against <i>Mycobacterium abscessus</i> subspecies <i>abscessus</i> and <i>Mycobacterium</i> subspecies <i>massiliense</i>. Most of <i>M.</i> subspecies <i>massiliense</i> were susceptible to clarithromycin, while the majority of <i>M. abscessus</i> subspecies abscessus were resistant to clarithromycin (p<0.001).Conclusion: There was an increasing trend of NTM isolation in our hospital. Resistance to key drugs was uncommon for most NTM species except for <i>M. abscessus</i> subspecies <i>abscessus</i> against clarithromycin.

Relationship between AdeABC Efflux Pump Genes and Carbapenem in Multidrug-resistant Acinetobacter baumannii

Yeongdon Ju,Yoo-Jeong Kim,Chulhun L. Chang,Go-Eun Choi,Kyung-Yae Hyun 대한의생명과학회 2021 Biomedical Science Letters Vol.27 No.2

Fluorogenic reaction-based prodrug conjugates as targeted cancer theranostics

Lee, Min Hee,Sharma, Amit,Chang, Min Jung,Lee, Jinju,Son, Subin,Sessler, Jonathan L.,Kang, Chulhun,Kim, Jong Seung The Royal Society of Chemistry 2018 Chemical Society reviews Vol.47 No.1

<P>Theranostic systems are receiving ever-increasing attention due to their potential therapeutic utility, imaging enhancement capability, and promise for advancing the field of personalized medicine, particularly as it relates to the diagnosis, staging, and treatment of cancer. In this Tutorial Review, we provide an introduction to the concepts of theranostic drug delivery effected <I>via</I> use of conjugates that are able to target cancer cells selectively, provide cytotoxic chemotherapeutics, and produce readily monitored imaging signals <I>in vitro</I> and <I>in vivo</I>. The underlying design concepts, requiring the synthesis of conjugates composed of imaging reporters, masked chemotherapeutic drugs, cleavable linkers, and cancer targeting ligands, are discussed. Particular emphasis is placed on highlighting the potential benefits of fluorogenic reaction-based targeted systems that are activated for both imaging and therapy by cellular entities, <I>e.g.</I>, thiols, reactive oxygen species and enzymes, which are present at relatively elevated levels in tumour environments, physiological characteristics of cancer, <I>e.g.</I>, hypoxia and acidic pH. Also discussed are systems activated by an external stimulus, such as light. The work summarized in this Tutorial Review will help define the role fluorogenic reaction-based, cancer-targeting theranostics may have in advancing drug discovery efforts, as well as improving our understanding of cellular uptake and drug release mechanisms.</P>

복부 연조직 농양 환자에서 농양 배양을 혈액배양병으로 했을 때의 성과 1예

조교진 ( Kyo Jin Jo ),장철훈 ( Chulhun L. Chang ),황재연 ( Jae-yeon Hwang ),박수은 ( Su Eun Park ) 대한소아감염학회 2021 Pediatric Infection and Vaccine Vol.28 No.2

세균 감염에서 적절한 항생제를 선택하려면 배양검사가 매우 중요하다. 저자들은 복부 연조직 감염의 농양을 혈액배양병을 사용하여 시행한 배양검사에서 Actinomyces radingae와 Clostridium ramosum이 배양된 증례를 경험하여 보고하고자 한다. 이전에 건강하였던 13세 남자 환자가 배꼽주변에 발생한 통증, 발적 및 발열을 주소로 응급실에 내원하였다. 환아는 복부 수술 및 외상의 병력은 없었다. 컴퓨터 단층 촬영에서 배꼽주위에 농양을 동반한 피부 연조직염이 확인되었고 선천성 기형은 없었다. 초음파 유도 흡인을 하여 8.5 mL의 화농성 농양이 흡인되었고, 농양은 혈액배양병을 이용하여 배양하였다. 농양 배양검사에서 A. radingae와 C. ramosum이 확인되었다. 감염증의 원인이 드문 세균일 가능성이 있는 경우 농양 배양을 할 때 일반적인 농양배양의 방법 보다는 혈액배양병을 사용하는 것이 원인균이 분리될 가능성을 높이고 더 빨리 확인할 수 있을 것으로 사료된다. Culture tests are very important in choosing the appropriate antibiotics for bacterial infections. In some cases, bacteria that could not be identified in standard culture bottles could be detected using blood culture bottles. A previously healthy 13-year-old boy visited our emergency room. He experienced pain, redness, and hardness of periumbilical skin and a fever for five days. There was no history of abdominal surgery and penetrating trauma. Computed tomography showed abscess with cellulitis at the periumbilical soft tissue with no congenital anomaly. Ultrasonography-guided aspiration was performed, and about 8.5 mL of the purulent abscess was aspirated. The abscess was cultured using blood culture bottle. The pus grew Actinomyces radingae and Clostridium ramosum. When performing the pus culture, using blood culture bottles can be more effective and rapid than the standard culture method for the detection of bacterial pathogens.

Evaluation of Dual-Color Fluorescence <i>In Situ</i> Hybridization With Peptide Nucleic Acid Probes for the Detection of <i>Mycobacterium tuberculosis</i> and Non-Tuberculous Mycobacteria in Clinical Specimens

Kim, Namhee,Lee, Seung Hee,Yi, Jongyoun,Chang, Chulhun L. The Korean Society for Laboratory Medicine 2015 Annals of Laboratory Medicine Vol.35 No.5

<P><B>Background</B></P><P>Peptide nucleic acid (PNA) probes are artificial DNA analogues with a hydrophobic nature that can penetrate the mycobacterial cell wall. We evaluated a FISH method for simultaneous detection and identification of <I>Mycobacterium tuberculosis</I> (MTB) and non-tuberculous mycobacteria (NTM) in clinical respiratory specimens using differentially labeled PNA probes.</P><P><B>Methods</B></P><P>PNA probes targeting the mycobacterial 16S ribosomal RNA were synthesized. The cross-reactivity of MTB- and NTM-specific probes was examined with reference strains and 10 other frequently isolated bacterial species. A total of 140 sputum specimens were analyzed, comprising 100 MTB-positive specimens, 21 NTM-positive specimens, and 19 MTB/NTM-negative specimens; all of them were previously confirmed by PCR and culture. The PNA FISH test results were graded by using the United States Centers for Disease Control and Prevention-recommended scale and compared with the results from the fluorochrome acid-fast bacterial stain.</P><P><B>Results</B></P><P>The MTB- and NTM-specific PNA probes showed no cross-reactivity with other tested bacterial species. The test results demonstrated 82.9% agreement with the culture results with diagnostic sensitivity of 80.2% and diagnostic specificity of 100.0% (kappa=0.52, 95% confidence interval: 0.370-0.676).</P><P><B>Conclusions</B></P><P>Dual-color PNA FISH showed high specificity for detecting and identifying mycobacteria in clinical specimens. However, because of its relatively low sensitivity, this method could be more applicable to culture confirmation. In application to direct specimens, the possibility of false-negative results needs to be considered.</P>

Prevalence of Plasmid-Mediated Quinolone Resistance and Mutations in the Gyrase and Topoisomerase IV Genes in <i>Salmonella</i> Isolated from 12 Tertiary-Care Hospitals in Korea

Jeong, Haeng Soon,Kim, Jeong A.,Shin, Jeong Hwan,Chang, Chulhun L.,Jeong, Joseph,Cho, Ji-Hyun,Kim, Mi-Na,Kim, Sunjoo,Kim, Young Ree,Lee, Chae Hoon,Lee, Kyungwon,Lee, Mi Ae,Lee, Wee Gyo,Shin, Jong Hee Mary Ann Liebert 2011 Microbial drug resistance Vol.17 No.4