중환자실에 근무하는 의료인의 전비강에서 PBP2a Rapid Kit와 직접 Coagulase 검사를 이용한 Methicillin-resistant Staphylococcus aureus의 검출

홍승복 ( Seung-bok Hong ),신경아 ( Kyung-a Shin ),손재철 ( Jae-cheol Son ),신경섭 ( Seob-kyeong Shin ) 대한임상검사과학회 2010 대한임상검사과학회지(KJCLS) Vol.42 No.2

We evaluated the performance of a novel screening test, PBP2a MRSA rapid kit (Dinona Inc., Iksan, Korea), for methicillin-resistant Staphylococcus aureus (MRSA) based on a immunochromatographic assay. The test is able to detect penicillin-binding protein 2a (PBP2a) using the nasal specimens from health care workers. The nasal specimens were obtained from 69 healthcare workers and were incubated in enrichment broth followed eight hours incubatin in BHI with cefoxitin 4 μg/mL. These broth were tested by PBP2a Rapid Kit. The enrichment broths were also directly tested for tube coagulase using the conventional identification method. 19 of 22 MRSA showed positive results by PBP2a rapid test and direct coagulase test (the sensitivity for detection of MRSA, 86.36%). While, 8 of 47 non-MRSA showed false positive results for the two tests. All of the 8 non-MRSA which showed false positive were co-colonizing isolates with MRCNS and MSSA. In addition, 46 of 49 methicillin-resistant staphylococci (MRS) showed positive results for PBP2a MRSA rapid kit (the sensitivity for detection of MRS, 93.8%), and all of 20 non-MRS showed negative results (specificity, 100%). The combination of PBP2a MRSA rapid kit and direct coagulase test showed the good sensitivity for detection of MRSA from anterior nares but frequently showed false positive results from the co-colonizing carrier with MRCNS and MSSA.

SE-9000 자동 혈구계산기에서 EDTA 검체의 보관기간 및 온도가 CBC 및 백혈구 감별계산에 미치는 영향

홍승복 ( Seung Bok Hong ),김종석 ( Jong Seok Kim ),신경섭 ( Kyeong Seob Shin ) 대한임상검사과학회 2006 대한임상검사과학회지(KJCLS) Vol.38 No.3

Although various automated CBC analyzers with different WBC analytical principles were consequently introduced to clinical laboratory, the specific information concerning the suitability or unsuitability of aging samples is scarce. For this reason, we studied the effect of storage duration and temperature on CBC parameter in SE-9000 (SYSMEX Medical Electronics Co., Ltd., Kobe, Japan), automated CBC analyzer. We tested 32 K3-EDTA specimens with SE-9000 during 72 hours. Specimens were kept at room temperature (RT) and refrigerated and were analyzed at 0 hr, 4 hr, 8 hr, 24 hr, 48 hr and 72 hr after the collection of the specimens. The percentage changes from initial value for each parameters were calculated. Among the CBC parameters, hemoglobin, red blood cell count, mean corpuscular hemoglobin and platelets were stable for the study period at both temperatures. The mean corpuscular volume (MCV), hematocrit (Hct) and red cell distribution (RDW) increased and the mean corpuscular hemoglobin concentration (MCHC) decreased over time at room temperature. These parameters were stable when refrigerated. The leukocyte count was stable during 72hr at RT and when refrigerated. At room temperature, the relative percentages of neutrophils tend to increase, whereas those of lymphocyte and monocytes tend to decrease after 48 hours. When refrigerated, those of neutrophils and monocytes tend to increase, whereas those of lymphocytes tend to decreased over time. CBC parameters of refrigerated specimen were reliable for 72 hr for the exception of differential count from 24 hr but many CBC parameters, such as MCV, Hct, MCHC, RDW and differential count of leukocyte of blood stored at room temperature for 24 hr were unreliable.

Hafnia alvei 에 의한 균혈증 1예

홍승복 ( Seung Bok Hong ),신경섭 ( Kyeong Seob Shin ) 대한임상검사과학회 2005 대한임상검사과학회지(KJCLS) Vol.37 No.2

Hafnia alvei is a gram-negative facultatively anaerobic bacillus that is rarely isolated from human specimens and is rarely considered to be pathogenic. It has been associated with gastroenteritis, pneumonia, meningitis, bacteremia, and nosocomial wound infections. But, only one case of extraintestinal H. alvei infection was documented in Korea to our knowledge. A 74-years old women with bronchial tuberculosis and cerebral infarct was admitted to out hospital via the internal medicine department due to the use of anti-tuberculotic agents. The two consecutive blood cultures yielded H. alvei. The organism was susceptible to all antimicrobial agents tested, except ampicillin and amoxacillin-clavulanic acid. The patients was treated with ceftriaxone and recovered effectively.

주요 임상 내성균에 대한 어성초 에탄올 추출물의 항균효과

홍승복 ( Seung Bok Hong ),이천휘 ( Chun Hee Lee ) 대한임상검사과학회 2015 대한임상검사과학회지(KJCLS) Vol.47 No.3

The increase in resistance by pathogenic bacteria to multiple antimicrobial agents has become a significant treat, as the effective antimicrobial agents available for the patients infected by such resistant bacteria are reduced, or even eliminated. Several natural plant extracts have exhibited antibacterial and synergistic activity against various resistant microorganisms. Houttuynia cordata is frequently used by many traditional medicine practicioners for its antimicrobial, antiviral, and anti-inflammatory properties. This study investigated the antibacterial effects of H. cordata extract against clinical multi-resistant bacteria, and compared the two methods used for the antimicrobial susceptibility testing. Thirty isolates of Methicillin-resistant Staphylococcus aureus (MRSA, 10), Vancomycin-resistant Enterococcus faecium (VRE, 10), Carbapenem-resistant Acinetobacter baumannii (CRAB, 10) were included in this study. The antibacterial effect of H. cordata was tested by disk diffusion and microbroth dilution methods as per CLSI guidelines. In disk diffusion, all isolates (30) showed no inhibition to 30,000 ug/mL of H. cordata. But in the microbroth dilution method, MIC90 of H. cordata was 4,096 ug/mL, 8,192 ug/mL and 4,096 ug/mL in MRSA, VRE and CRAB, respectively. These results demonstrate that H. cordata exhibits antibacterial activity against MRSA, VRE and CRAB. Moreover, the microbroth dilution method is a more effective method than disk diffusion to evaluate the antibacterial activity of natural products. The Disk diffusion method used to evaluate the antibacterial activity of natural products required new standard guidelines including inoculum concentration of bacteria.

Coulter® LH 750TM에 의한 백혈구 감별계산 및 Suspect Flags의 평가

홍승복 ( Seung Bok Hong ),최종태 ( Jong Tae Choi ),이성규 ( Seong Kyu Lee ),김현수 ( Hyun Soo Kim ) 대한임상검사과학회 2005 대한임상검사과학회지(KJCLS) Vol.37 No.3

Automatic hematology analyzers provide the leukocyte differential count and the useful flags of the various hematological parameters. We compared LH 750 (Beckman Coulter Co., Miami, FL, USA) with manual method on differential leukocyte counts and evaluated the usefulness of the suspect flags, provided by this instrument. The comparison of leukocyte differential counts between two methods showed good correlation coefficient (r), which were 0.95 (neutrophil), 0.92 (lymphocyte), 0.82 (monocyte) and 0.95 (eosinophil). The frequency of the total flags displayed on LH 750 were 15.5%, which included immature granulocyte/left shift 63.5%, nucleated RBC 14.6%, platelet clumps 13.1%, variant lymphocyte 50% and blast 16.6%. This instrument showed higher positive predictive value in the flags such as platelet clumps 68.8%, immature granulocyte/left shift 61.5%, nucleated RBC 27.3%, variant lymphocyte 50% and blast 16.7%. In this study, the leukocyte differential counts of LH 750 showed good correlation with manual method and the suspect flags also showed a good performance for applying the criteria of re-examination in the clinical laboratory.

Evaluation of EDTA-based Three Methods to Detect IMP-1 and VIM-2 Type Metallo-β-Lactamase-Producing Clinical Isolates of Imipenem Resistant Acinetobacter and Pseudomonas spp.

Seung Bok Hong(홍승복),Kyung-A Shin,Seock Yeon Hwang 대한의생명과학회 2011 Biomedical Science Letters Vol.17 No.2

We compared three EDTA-based phenotypic screening methods for detecting IMP-1 and VIM-2 type metallo-β-lactamase (MBL)-producing isolates of Acinetobacter and Pseudomonas spp., EDTA-double disk synergy test (EDTADDST), Etest MBL, and imipenem (IPM)-EDTA disk test. A total of 183 isolates (65 Acinetobacter spp. and 118 Pseudomonas spp. showing IPM resistance), confirmed to MBL genes by PCR, were used. The criteria for MBL production were (ⅰ) presence of a synergistic zone between IPM and EDTA disks in EDTA-DDST, (ⅱ) reduction of IPM minimal inhibitory concentration by ≥ 3 twofold dilutions in the presence of EDTA in the Etest MBL, and (ⅲ) ≥ 7 ㎜ increase in the inhibition zone around the IPM plus EDTA disks compared with a sole IPM disk in the IPM-EDTA disk test. In this study using 87 MBL-producing and 96 MBL-nonproducing isolates, the sensitivities/specificities of EDTA-DDST, Etest MBL and IPM-EDTA disk tests were 94.3/78.1%, 89.7/91.7%, and 97.7/95.8%, respectively. When the threshold for the increase of the inhibition zone around the IPM plus EDTA disk over a sole IPM disk was altered to ≥ 5 ㎜ and ≥ 8 ㎜ for Acinetobacter spp. and Pseudomonas spp., respectively, the sensitivity and specificity of the test were 98.9% and 96.9%, respectively. Of the three EDTA-based phenotypic tests, the IMP-EDTA disk test was superior for detection of MBL-producing isolates.

Metallo-β-lactamase 생성 Pseudomonas aeruginosa의 시험관내 항균제 병합요법에 대한 연구

홍승복 ( Seung Bok Hong ) 대한임상검사과학회 2006 대한임상검사과학회지(KJCLS) Vol.38 No.3

Metallo-β-lactamase (MBL) can hydrolyze all β-lactams except monobactams and frequently coexists with various antibiotic resistance genes such as aminoglycoside resistance, sulfonamide resistance gene, etc. Therefore, the effective antibiotics against infections by these bacteria are markedly limited or can``t even be found. We tried to search in-vitro antimicrobial combinations with synergistic effects for a VIM-2 type MBL producing Pseudomonas aeruginosa, isolated from clinical specimen. On the selection of antibiotic combinations with synergistic effects, we performed a one disk synergy test, modified Pestel``s method, in agar without aztreonam (AZT). The bacteriostatic synergistic effects of this tests were scored as S1 (by susceptibility pattern in agar without antibiotics), S2 (by the change of susceptibility in agar with or without antibiotics) and S3 (S1 + S2) and was classified into weak (1 point), moderate (2 points) and strong (3 points) by S3 score. Subsequently, we carried out the time-killing curve for the antibiotic combinations with the strong synergistic bacteriostatic effect. One VIM-2 type MBL producing P. aeruginosa confirmed by the PCR showed all resistance against all β-lactams except AZT, aminoglycoside and ciprofloxacin. In the one disk synergy test, this isolate showed a strong bacteriostatic synergistic effect for the antibiotic combination of AZT and piperacillin-tazobactam (PIP-TZP) or AZT and amikacin (AN). On the time-killing curve after six hours of incubation, the colony forming units (CFUs/mL) of this bacteria in the medium broth with both combination antibiotics were decreased to 1/18.7, 1/17.1 of the least CFUs of each single antibiotics. The triple antibiotic combination therapy including AZT, PIP-TZP and AN was shown to be significantly synergistic after 8 hrs of exposure. In a VIM-2 MBL producing P. aeruginosa with susceptibility for AZT, the triple antibiotic combination therapy including AZT, PIP-TZP and AN may be considered as an alternative antibiotics modality against the infection by some MBL type. But the antimicrobial combination therapy for many more MBL producing isolates is essential to know as soon as possible for the selection of effective treatment against the infection by this bacteria.

당화혈색소 측정을 위한 Norudiaⓡ HbA1c 키트의 평가

홍승복 ( Seung Bok Hong ),김은중 ( Eun Joong Kim ) 대한임상검사과학회 2009 대한임상검사과학회지(KJCLS) Vol.41 No.1

Measurement of hemoglobin A1c is used as an objective indicator of long-term blood glucose control in diabetic patients. We evaluated recently introduced Norudiaⓡ HbA1c (Daiichi Pure Chemical Co. Ltd, Tokyo, Japan) test reagent using enzyme method for HbA1c assay. Linearity, precision and correlation with VARIANTTM II Turbo HbA1c analyzer (BIO-RAD, Hercules, CA, USA) were evaluated. The reference range was determined from 201 healthy subjects. The Norudiaⓡ HbA1c test reagent was founded to be linear in a range of 5.6% to 14.0% (r2=0.9885). The within-run and between-day precision were 0.954% and 1.03% for low level (HbA1c 5.24%), 0.67% and 1.28% for high level (HbA1c 9.01%), respectively. Comparison study between Norudiaⓡ HbA1c test reagent and VARIANTTM II Turbo showed good correlation with a slope of 1.0489. an intercept at -0.9717, and coefficient of correlation was 0.9907. The reference range of HbA1c obtained from this reagent was 4.07-5.50%. The Norudiaⓡ HbA1c test reagent showed good linearity, precision and correlation with HbA1c analyzer with HPLC method. In addition, the exclusive analyzer is not required for assay and then this kit may be useful for HbA1c assay in clinical laboratory.

한국 노인의 대사증후군 예측인자로서 혈중 Non HDL 콜레스테롤과 중성지방/HDL 콜레스테롤 비의 의의

홍승복 ( Seung Bok Hong ),신경아 ( Kyung-a Shin ) 대한임상검사과학회 2018 대한임상검사과학회지(KJCLS) Vol.50 No.3

한국 노인을 대상으로 대사증후군 예측인자로서 혈중 Non HDL-콜레스테롤과 중성지방/HDL-콜레스테롤 비율의 임상적용 가능성을 평가하고자 하였다. 2015년 1월부터 2017년 12월까지 경기지역 종합병원의 건강검진센터를 내원하여 건강검진을 실시한 65세 이상 노인을 1,543명을 대상으로 하였다. 대사증후군은 American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI)기준에 따라 진단하였다. 복부비만은 World Health Organization (WHO) West Pacific Region에서 제시하는 아시아-태평양인의 기준을 적용하였다. Non HDL-콜레스테롤은 총콜레스테롤과 HDL-콜레스테롤의 차이로 계산하였다. 대사증후군 예측력은 Non HDL-콜레스테롤보다 중성지방/HDL-콜레스테롤 비율이 높게 나타났다. 관련요인을 보정한 후 중성지방/HDL-콜레스테롤 비율은 1사분위수보다 4사분위수의 대사증후군 발병 위험이 높았다. 또한 대사증후군 발병을 예측하는 중성지방/HDL-콜레스테롤 비율의 적정 기준값은 2.8이었다. 중성지방/HDL-콜레스테롤 비율은 대사증후군 위험을 평가하는 간단하고 실용적인 지표가 될 수 있겠다. We evaluated the possible clinical application of Non HDL-cholesterol and triglyceride to HDL-cholesterol ratio as a metabolic syndrome predictor for the elderly in Korea. 1,543 elderly persons aged 65 years or older who visited the health examination center of Gyeonggi Regional General Hospital from January 2015 to December 2017 and had a health checkup were enrolled in this study. Metabolic syndrome was diagnosed based on the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) standards. Abdominal obesity was assessed by the Asia-Pacific standards presented at the World Health Organization (WHO) West Pacific Region. Non-HDL-cholesterol was calculated as the difference between total cholesterol and HDLcholesterol. The metabolic syndrome predictive power was higher for triglyceride to HDLcholesterol ratio than for Non HDL-cholesterol. After correcting for related factors, triglyceride to HDL-cholesterol ratio was higher in the 4^th quartile, which had a higher risk of developing metabolic syndrome, than in the 1^st quartile. The optimal cutoff value for the triglyceride to HDL-cholesterol ratio that predicts the onset of metabolic syndrome was 2.8. triglyceride to HDL-cholesterol ratio can be a simple and practical indicator of the risk of metabolic syndrome.

당화혈색소 측정을 위한 Norudia^® HbA1c 키트의 평가

홍승복,김은중,Hong, Seung-Bok,Kim, Eun-Joong 대한임상검사과학회 2009 대한임상검사과학회지(KJCLS) Vol.41 No.1

Measurement of hemoglobin A1c is used as an objective indicator of long-term blood glucose control in diabetic patients. We evaluated recently introduced Norudia$^{(R)}$ HbA1c (Daiichi Pure Chemical Co. Ltd, Tokyo, Japan) test reagent using enzyme method for HbA1c assay. Linearity, precision and correlation with VARIANT$^{TM}$ II Turbo HbA1c analyzer (BIO-RAD, Hercules, CA, USA) were evaluated. The reference range was determined from 201 healthy subjects. The Norudia$^{(R)}$ HbA1c test reagent was founded to be linear in a range of 5.6% to 14.0% ($r^2=0.9885$). The within-run and between-day precision were 0.954% and 1.03% for low level (HbA1c 5.24%), 0.67% and 1.28% for high level (HbA1c 9.01%), respectively. Comparison study between Norudia$^{(R)}$ HbA1c test reagent and VARIANT$^{TM}$ II Turbo showed good correlation with a slope of 1.0489. an intercept at -0.9717, and coefficient of correlation was 0.9907. The reference range of HbA1c obtained from this reagent was 4.07-5.50%. The Norudia$^{(R)}$ HbA1c test reagent showed good linearity, precision and correlation with HbA1c analyzer with HPLC method. In addition, the exclusive analyzer is not required for assay and then this kit may be useful for HbA1c assay in clinical laboratory.