Original article Kang Ju Son1,2, Young Ah Kim3, Yoon Soo Park4 1Department of Research and Analysis, National Health Insurance Service Ilsan Hospital, Goyang, 2Department of Biostatistics and Computing, Yonsei University Graduate School, Seoul, 3Department of Laboratory Medicine, National Health Insurance Service Ilsan Hospital, Goyang, 4Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea Corresponding to Young Ah Kim, E-mail: yakim@nhimc.or.kr Ann Clin Microbiol 2020;23(4):181-189. https://doi.org/10.5145/ACM.2020.23.4.3Received on 9 April 2020, Revised on 23 June 2020, Accepted on 23 June 2020, Published on 20 December 2020.Copyright © Korean Society of Clinical Microbiology. Abstract Background: Clostridioides (Clostridium) difficile is an important pathogen that causes diarrhea in people who take antibiotics. The recent status of C. difficile infection is not well-known in Korea. Methods: The long-term trend of C. difficile infection in Korean hospitals was analyzed using a nationwide sample cohort. The data also included sociodemographic characteristics, disease severity, and healthcare facilities.

Original article PDF Gyu Yel Hwang, Young Uh, Hyun-Joo Kim, In Ho Jang, and Kap Jun Yoon Department of Clinical Pathology, Yonsei University Wonju College of Medicine, Wonju, Korea Corresponding to Young Uh Ann Clin Microbiol 2001;4(1):62-66.Copyright © Korean Society of Clinical Microbiology. Abstract Background : Accurate detection of extended spectrum β-lactamase (ESBL) is important because ESBLs producing organisms may appear susceptible to oxyimino-β-lactams in standard susceptibility tests, but are considered to be clinically resistant to these drugs. Conventional antimicrobial susceptibility test methods do not reliably detect ESBL production. Molecular techniques and NCCLS broth dilution method, which detect ESBL production, may be time consuming, expensive and technically difficult to perform. The purpose of this study is to evaluate the clinical usefulness of NCCLS ESBL phenotypic confirmatory test by disk diffusion method. Methods : For 96 Escherichia coli and 49 Klebsiella pneumoniae isolates collected between December 2000 to February 2001, double disk synergy test, NCCLS

Original article PDF Young Uh, M.D., In Ho Jang, M.S., Kap Jun Yoon, M.D., Hyun Soo Kim*, M.D., and Hyo Youl Kim*, M.D. Departments of Clinical Pathology and Internal Medicine*, Yonsei University Wonju College of Medicine, Wonju, Korea Corresponding to Young Uh Ann Clin Microbiol 2001;4(1):28-32.Copyright © Korean Society of Clinical Microbiology. Abstract Background : Vibrio species may be classified as halophilic or nonhalophilic on the basis of their requirement of NaCl for optimal growth. Recently, attention has been focused on the halophilic vibrios and Vibrio cholerae non-O1/O139 causing extraintestinal infections such as septicemia. The aim of this study is to elucidate the isolation rate and clinical manifestations of Vibrio species isolated from clinical specimens between 1996 and 2000 at Wonju Christian Hospital. Methods : Stool specimens were inoculated onto the thiosulfate-citrate-bile salt-sucrose media, blood cultures were performed by automated blood culture systems with commercial bottles, and the others were cultured according to the routine procedures. Results :

Original article PDF Hei Kyung Jin1, Jae Yun Jang1, Young Uh1, Ohgun Kwon1, Kap Jun Yoon1, Hyo Youl Kim2, Young Keun Kim2 Departments of 1Laboratory Medicine and 2Infectious Diseases, Yonsei University Wonju College of Medicine, Wonju, Korea Corresponding to Young Uh, E-mail: u931018@yonsei.ac.kr Ann Clin Microbiol 2011;14(1):7-12. https://doi.org/10.5145/KJCM.2011.14.1.7Copyright © Korean Society of Clinical Microbiology. Abstract Background: Bacteremia is a life-threatening infection, and prognosis is highly dependent on early recognition and treatment with appropriate antimicrobial agents. We investigated the diagnostic performance of serum procalcitonin (PCT) for differentiation between contaminants and true pathogens in blood cultures.  Methods: Serum PCT, C-reactive protein (CRP) and blood culture were performed for 473 patients between February 2008 and October 2008. We retrospectively reviewed the patients’ clinical characteristics and laboratory results based on medical records.  Results: The mean concentration of PCT was significantly different between the two negative and positive blood culture groups (6.45 ng/mL vs 28.77

Research note PDF Tae Sang Oh1, Hee Yoon Kang2, You Sun Nam1, Young Jin Kim2, Eun Kyung You2, Min Young Lee2, Sun Young Cho2, Hee Joo Lee2 1Department of Biomedical Science, Graduate School, Kyung Hee University, 2Department of Laboratory Medicine, Kyung Hee University School of Medicine, Seoul, Korea Corresponding to Hee Joo Lee, E-mail: leehejo@khmc.or.kr Ann Clin Microbiol 2016;19(1):20-23. https://doi.org/10.5145/ACM.2016.19.1.20Copyright © Korean Society of Clinical Microbiology. Abstract In the RNA-based study, it is important to extract high-quality RNA. However, RNA extraction from Mycobacterium tuberculosis is problematic due to its thick, waxy cell wall rich in mycolic acid, which renders the cells resistant to lysis. Using TRIzol reagent and several powerful bead-beating steps, a high quantity of RNA was obtained. (Ann Clin Microbiol 2016; 19:20-23) Keywords Mycobacterium tuberculosis, RNA extraction, Quantitative reverse transcription polymerase chain reaction

Original article PDF Young Ah Kim1, Yoon Soo Park2, Hyunsoo Kim3, Young Hee Seo4, Kyungwon Lee4,5 Departments of 1Laboratory Medicine, 2Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, 3Department of Laboratory Medicine, National Police Hospital, 4Research Institute of Bacterial Resistance and 5Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea Corresponding to Yoon Soo Park, E-mail: yspark@nhimc.or.kr Ann Clin Microbiol 2018;21(2):28-35. https://doi.org/10.5145/ACM.2018.21.2.28Copyright © Korean Society of Clinical Microbiology. Abstract Background: In the present study, the prevalence and risk factors for acquisition of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in intensive care unit (ICU) settings without outbreak in the situation of widespread sequence type (ST) 131 ESBL-producing E. coli in a Korean community was investigated. Methods: Consecutive and prospective screening of ESBL-producing E. coli colonization was performed in all patients admitted to surgical or medical ICUs within 48 hours for two months. ESBL genotype was determined based on PCR and sequencing. PCR for O16-ST131/O25-ST131 was performed for all ESBL producers. Clinical

Case report PDF Tae Yeul Kim1*, Juyeon Jo2, Namhee Kim1,2, Hyunwoong Park1,2, Eun Youn Roh1,2, Jong Hyun Yoon1,2, Sue Shin1,2 1Department of Laboratory Medicine, Seoul National University College of Medicine, 2Department of Laboratory Medicine, Seoul National University Boramae Medical Center, Seoul, Korea Corresponding to Sue Shin, E-mail: jeannie@snu.ac.kr Ann Clin Microbiol 2019;22(2):50-54. https://doi.org/10.5145/ACM.2019.22.2.50Copyright © Korean Society of Clinical Microbiology. Abstract Facklamia hominis is a facultative anaerobic Gram- positive coccus generally displaying weak alpha-hemolysis and negativity for catalase and oxidase. Facklamia species are part of the normal flora of the female genitourinary tract and have been reported in invasive diseases such as meningitis and infective endocarditis, albeit rarely. A 67 year-old-man presented to hospital with a tender, erythematous epidermal cyst on the right side of his upper back. Simple excision of the cyst was performed and the pus was taken with a sterile swab for culture, yielding no growth. One week later, discharge was observed