Original article Young-Suk Sohn1, Jung-Hyun Byun2, Young Ah Kim3, Dong-Chun Shin4, Kyungwon Lee1 1Department of Laboratory Medicine, Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, 2Department of Laboratory Medicine, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, 3Department of Laboratory Medicine, National Health Insurance Service Ilsan Hospital, Goyang, 4Department of Environmental Health Graduate School of Public Health, Yonsei University, Seoul, Korea Corresponding to Young Ah Kim, E-mail: yakim@nhimc.or.kr Ann Clin Microbiol 2020;23(1):33-43. https://doi.org/10.5145/ACM.2020.23.1.33Received on 8 July 2019, Revised on 23 August 2019, Accepted on 23 August 2019, Published on 20 March 2019.Copyright © Korean Society of Clinical Microbiology. Abstract Background: The weather has well-documented effects on infectious disease and reports suggest that summer peaks in the incidences of gram-negative bacterial infections among hospitalized patients. We evaluated how season and temperature changes affect bloodstream infection (BSI) incidences of major pathogens to understand BSI trends with

Case report PDF Jeong Won Shin, M.D., Kyoung Ho Roh., M.D., Kyungwon Lee, M.D. and Yunsop Chong, Ph.D. Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea Corresponding to Kyungwon Lee Ann Clin Microbiol 1999;2(2):220-224.Copyright © Korean Society of Clinical Microbiology. Abstract Group B Streptococcus (GBS, S. agalactiae) is known to be the leading cause of neonatal sepsis and meningitis and the infection has been increasingly noted in adults, particularly in those with underlying diseases. Penicillin G is the drug of choice for GBS infection. However, the MIC of penicillin for GBS is greater than that for S. pyogenes. Therefore some GBS infections may be difficult to be treated. However, in Korea, our knowledge on GBS infection is limited. We observed 7 cases of GBS bacteremia during 1993-1996 in a hospital. Of the 7 patients, 3 were less than one month of age with no known

Original article PDF Jae Lim Chung, M.D., Young Ah Kim, M.D., Hee Bong Shin, M.D., Jeong Won Shin, M.D., Kyungwon Lee, M.D., Yunsop Chong, Ph.D., Jang Hyeon Park, Ph.D.* and Won Bae Kim, Ph.D.* Department of Clinical Pathology and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Research Laboratories, Dong-A Pharm. Co., Ltd., Yongin, Kyunggi-do, Korea* Corresponding to Kyungwon Lee Ann Clin Microbiol 1999;2(2):182-193.Copyright © Korean Society of Clinical Microbiology. Abstract Background: β-lactam antibiotics are one of the most frequently used antimicrobial agents. However, with the increase of β-lactamase-producing bacteria, penicillins and 1st generation cephalosporins have become less useful. Cefatrizine and clavulanic acid combination (CTCA) was developed to restore the activity. The aim of this study was to determine the activities of CTCA against major recent clinical isolates. Methods: Aerobic and anaerobic bacteria tested were isolated from clinical specimens in Severance Hospital during 1996 to 1999. Antimicrobial

Original article PDF Hyukmin Lee, M.D., Young Ah Kim, M.D., Kwang Il Park, M.D., Kyungwon Lee, M.D. and Yunsop Chong, Ph.D. Department of Clinical Pathology and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea Corresponding to Kyungwon Lee Ann Clin Microbiol 1999;2(1):77-81.Copyright © Korean Society of Clinical Microbiology. Abstract Background：Clostridium difficile causes antibiotic-associated diarrhea or pseudomembranous colitis by producing of toxins in patients treated with antimicrobial agents. Stool cultures for C. difficile and tests for the presence of its toxin are the most widely used methods for the diagnosis of infection. The aim of this study was to determine the usefulness of polymerase chain reaction for the detection of toxin B gene from C. difficile isolates. Methods：In this study, 85 strains of C. difficile were used, which were isolated from stool specimens of patients with suspected antibiotic-associated diarrhea or pseudomembranous colitis from 1987 to 1994 using cefoxitin-cycloserine-fructose agar. DNA of the C. difficile isolates was

Original article PDF Byung Lip Kim*, M.D., Seok Hoon Jeong, M.D., Ja Young Koo*, M.D., Kyungwon Lee**, M.D., Yunsop Chong**, Ph.D., Tae Jeon Jeong, M.T., Hyun Yong Hwang, M.D. and Mi Hyang Kim, M.D. Department of Internal Medicine* and Clinical Pathology, College of Medicine Kosin University, Pusan, and Department of Clinical Pathology, College of Medicine Yonsei University, Seoul, Korea** Corresponding to Seok Hoon Jeong Ann Clin Microbiol 1999;2(1):28-39.Copyright © Korean Society of Clinical Microbiology. Abstract Background ： Increased isolation of extended-spectrum β-lactamase ( ESBL)-producing Enterobacteriaceae resistant to third generation cephalosporins and aztreonam has been noted recently. This study was to determine the prevalence of resistance to these drugs and ESBL in Enterobacteriaceae and to evaluate the methods for detection. Methods：During the period of October, 1997 and March, 1998, a total of 731 clinical isolates of Enterobacteriaceae were collected from patients of the Kosin Medical Center, Pusan, Korea. Antimicrobial susceptibility test by disk diffusion method and double disk synergy

Review article PDF Kyungwon Lee, M.D. and Yunsop Chong, Ph.D. Department of Clinical Pathology and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea Corresponding to Kyungwon Lee Ann Clin Microbiol 2000;3(2):83-88.Copyright © Korean Society of Clinical Microbiology. Abstract 감염 질환을 흔히 일으키는 세균 중에 항균제 내성의 혼합을 이미 많이 알려져 있다. 특히 트랜스포존이 세 널리 사용되는 항균제에 대한 다제 내성 세균이 대단히 흔해졌다. Pseudomonas 감염 치료를 위해서는 유효한 항균제 선택에 어려움을 겪는 경우가 흔하다(1). 그람음성 간균 내성 유전자는 plasmid, 염색체 혹은 transposon에 들어있는 것이 발견되어, 이들 중에는 여러 가지 내성 유전자를 가지고 있어 다제 내성을 나타낸다. 내성 유전자가 integron이라고 하는 구조 중에 들어 있는 경우가 있다. 즉, 세균의 염색체나 plasmid 혹은 transposon이 있고, plasmid나 transposon 구조 중에는 integron이 있고, integron 중에는 cassette가 있으며, cassette 중에는 내성 유전자가 들어있는 경우가 있다(2). Integron은 현재 4 종류가 알려져 있으며, 그 중 class 1, 2 및 3 integron은 항균제 내성

Case report PDF Hyukmin Lee, M.D., Kyungja Woo, M.T., Kyungwon Lee, M.D., Yunsop Chong, Ph.D., and Joo Hang Kim, M.D.* Departments of Clinical Pathology and Internal Medicine*, Yonsei University College of Medicine, Seoul, Korea Corresponding to Kyungwon Lee Ann Clin Microbiol 2000;3(2):137-141.Copyright © Korean Society of Clinical Microbiology. Abstract Plesiomonas shigelloides was isolated from blood culture of a 53-year-old man with fever, who had treatment history of gastrointestinal malignancy. The patient showed neither clinical features nor hematological finding which suggest bacteremia. Identification of the isolate was delayed because of its similar characteristics with Aeromonas spp. and other gram-negative bacilli. The isolate was misinterpreted as susceptible to ampicillin by the first disk diffusion test. It may not always easy to identify P. shigelloides by conventional tests and to determine its antimicrobial susceptibility accurately, as laboratorians rarely have experience with the organism and as the organism may show unusual inhibition pattern when tested by disk diffusion method

Original article PDF Hee Bong Shin*, Seok Hoon Jeong**, Myeungsuk Kim***, Won Ho Kim****, Kyungwon Lee*, and Yunsop Chong* Departments of Clinical Pathology* and Internal Medicine****, Yonsei University College of Medicine, Seoul, Korea Departments of Clinical Pathology***, Severnce Hospital, Seoul, Korea Departments of Clinical Pathology, College of Medicine, Kosin University**, Busan, Korea Corresponding to Kyungwon Lee, E-mail: leekcp@yumc.yonsei.ac.kr Ann Clin Microbiol 2001;4(2):87-95.Copyright © Korean Society of Clinical Microbiology. Abstract Background: Diarrheal disease has been one of the most common health problem in Korea with Salmonella and Shigella being the major bacterial pathogens. Prevalence of enteric bacterial pathogens may differ significantly depending on the socioeconomic status of a country. Therefore, rapid improvement of living conditions in Korea should have profound effect on the incidence of enteric infection. In some Salmonella infections, proper antimicrobial treatment is important to reduce morbidity and mortality, but rapid change of the susceptibility makes the susceptibility unpredictable. So, there is a need to

Original article PDF Myungsook Kim*,** Sunhee Kim* Giyeon Kang,* Dongeun Yong*,**, Kyungwon Lee*,**, Yunsop Chong,*,** and Shin Moo Kim*** Department of Laboratory Medicine,* Research Institute of Bacterial Resistance,** Yonsei University College of Medicine, Seoul; Department of Clinical Pathology, Wonkwang Health Science College, Iksan, Chonbuk, Korea Corresponding to Kyungwon Lee, E-mail: leekcp@yumc.yonsei.ac.kr Ann Clin Microbiol 2002;5(2):129-136.Copyright © Korean Society of Clinical Microbiology. Abstract Background: Rapid species identification of enterococci is necessary for optimal treatment of infected patients as they are frequently resistant to various antimicrobial agents. Minimal identification scheme is necessary to cut the laboratory cost. In this study, a minimal identification system was modified to expand the identifiable species. Methods:Performance of MGP test was compared to that of MIO motility test. Colonies on blood agar were used to inoculate primary identification media: SFA, BEAA, mannitol agar, tellurite agar, sorbose agar and MGP agar, which were prepared in biplates. Pigment production

Original article PDF Dongeun Yong, M.D.,* Hyuk Min Lee, M.D.,* Jong Ha Ryu, M.D.,* Kyung Ho Roh, M.D.,* Won Ho Kim, M.D.,**,*** Kyungwon Lee, M.D.,*,*** and Yunsop Chong, M.D. Department of Laboratory Medicine, Research Institute of Bacterial Resistance,* Department of Internal Medicine,** and Brain Korea 21 Project for Medical Sciences,*** Yonsei University College of Medicine, Seoul, Korea Corresponding to Kyungwon Lee, E-mail: leekcp@yumc.yonsei.ac.kr Ann Clin Microbiol 2002;5(2):124-128.Copyright © Korean Society of Clinical Microbiology. Abstract Background: C. difficile-associated diarrhea (CDAD), the most frequently identified cause of nosocomial diarrhea, results from the overgrowth of cytotoxin (toxin B)-producing strains. The aim of this study was to evaluate the quantitative culture of Clostridium difficile to improve the laboratory diagnosis of CDAD. Methods: The quantitative culture and cytotoxin gene results were evaluated based on the findings of colonoscopy and/or histology of the biopsy specimens. Results: Among the 402 specimens with cytotoxin-positive isolates, 301 (74.9%) contained ≥106 CFU/mL of C. difficile.