Measurements of surgeons’ exposure to ionizing radiation dose: comparison of conventional and mini C-arm fluoroscopy

Sung, K. H.,Min, E.,Chung, C. Y.,Jo, B. C.,Park, M. S.,Lee, K. SAGE Publications 2016 The journal of hand surgery. journal of the Britis Vol.41 No.3

<P>This study was performed to measure the equivalent scattered radiation dose delivered to susceptible organs while simulating orthopaedic surgery using conventional and mini C-arm fluoroscopy. In addition, shielding effects on the thyroid, thymus, and gonad, and the direct exposure delivered to the patient's hands were also compared. A conventional and mini C-arms were installed in an operating room, and a hand and an operator phantom were used to simulate a patient's hand and a surgeon. Photoluminescence dosimeters were used to measure the equivalent dose by scattered radiation arriving at the thyroid, thymus, and gonad on a whole-body phantom in the position of the surgeon. Equivalent scattered radiation doses were measured in four groups: (1) unshielded conventional C-arm group; (2) unshielded mini C-arm group; (3) lead-shielded conventional C-arm group; and (4) lead-shielded mini C-arm group. Equivalent scattered radiation doses to the unshielded group were significantly lower in the mini C-arm group than those in the conventional C-arm group for all organs. The gonad in the lead-shielded conventional C-arm group showed the highest equivalent dose among operator-susceptible organs, and radiation dose was reduced by approximately 96% compared with that in the unshielded group. Scattered radiation was not detected in any susceptible organ in the lead-shielded mini C-arm group. The direct radiation dose to the hand phantom measured from the mini C-arm was significantly lower than that measured from the conventional C-arm. The results show that the equivalent scattered radiation dose to the surgeon's susceptible organs and the direct radiation dose to a patient's hand can be decreased significantly by using a mini C-arm rather than a conventional C-arm. However, protective lead garments, such as a thyroid shield and apron, should be applied to minimize radiation exposure to susceptible organs, even during use of mini C-arm fluoroscopy.</P>

감염성 안질환의 원인균 및 항생제 감수성에 대한 10년간의 고찰

최현태,이동욱,안민,조남천,유인천,Hyun Tae Choi,Dong-Wook Lee,Min Ahn,Nam Chun Cho,In Cheon You 대한안과학회 2012 대한안과학회지 Vol.53 No.7

Purpose: To investigate the ocular regional incidence, causative species and antibiotic susceptibility in patients with infectious ocular disease whose causative organism was isolated. Methods: A total of 519 eyes in 519 patients with infectious ocular disease, who were diagnosed by smears and cultures from January 2000 to December 2009 were retrospectively reviewed. Results: The mean age of the 519 patients was 54.0 years, and 66.1% of the patients were male. The most common systemic disease was diabetes mellitus. The most common previous ocular disease was keratoconjunctivitis. Specimens were most frequently swabbed from the cornea, where 81.2% were bacteria isolates and 18.8% fungi isolates. The most prevalent causative organism was Staphylococcus epidermidis, and the most prevalent fungus was Fusarium species. Vancomycin, ceftazidime, and fourth-generation fluoroquinolone maintained high antibiotic susceptibility. Methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus epidermidis were increasing near the end of the reference period, and endophthalmitis was more common in methicillin-resistant Staphylococcus. Conclusions: Identifying the causative organism in infectious ocular disease by smears and cultures is essential. More effective treatment of infectious ocular disease would be possible by analyzing the frequent organism, clinical manifestations, and antibiotic susceptibility. More caution is necessary due to the increase in methicillin-resistant Staphylococcus. J Korean Ophthalmol Soc 2012;53(7):934-940

단일 신생아중환자실에서 경험한 10년간의 신생아 패혈증의 원인균 및 항생제 감수성 변화

박혜원,구소은,이병섭,김기수,피수영,김애란,임진아 대한신생아학회 2009 Neonatal medicine Vol.16 No.2

Purpose : To identify trends in causative bacterial organisms for neonatal sepsis and antimicrobial susceptibilities over 10 years in one neonatal intensive care unit. Methods : We retrospectively reviewed the cases of culture-proven neonatal sepsis between January 1998 and December 2007. The 10-year period was divided into two phases (phase I, 1998-2002; phase II, 2003-2007) to distinguish the differences during the entire period. Results : Total 350 episodes of neonatal sepsis were identified in 315 neonates. The common pathogens of early-onset sepsis were S. epidermidis, S. aureus, P. aeruginosa, and E. cloacae in phase I, and S. epidermidis and E. cloacae in phase II. In cases of late- onset sepsis, coagulase negative Staphylococcus, S. aureus, and K. pneumoniae were isolated frequently in both phases. The incidence of sepsis caused by multi-drug resistant organisms decreased with strict infection control. Gram positive organisms showed 0-20% susceptibility to penicillin, ampicillin, and cefotaxime in both phases. Sensitivity to amikacin for Enterobacter spp. increased, whereas P. aeruginosa showed decreased sensitivity in phase II. Between 50% and 60% of other gram negative bacteria, except P. aeruginosa, were susceptible to cefotaxime in phase II in contrast to phase I. Greater than 80% of gram negative bacteria were sensitive to imipenem except P. aeruginosa and ciprofloxacin in both phases. Conclusion : The trend in causative microorganisms and antimicrobial susceptibilities can be used as a guideline for selection of appropriate antibiotics. A particular attention should be paid to infection control, especially to reduce sepsis caused by multi-drug resistant organisms.

Diagnosis of Subclinical Mastitis-Causing Pathogens Using MALDI-TOF Mass Spectrometry in a Certified Organic Dairy Farm in Korea

Sung Jae Kim,Hyun-Tae Kim,Yo-Han Kim The Korean Society of Veterinary Clinics 2023 한국임상수의학회지 Vol.40 No.6

We identified mastitis-causing pathogens using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) in an organic dairy farm and evaluated the effects of antimicrobial restriction on antimicrobial susceptibility. A total of 43 Holstein cows without any clinical sign of mastitis were used in this study, and 172 quarter milk samples were cultured on blood agar plates for 24 hours at 37℃. Subsequently, bacterial species were identified and antimicrobial susceptibility tests were performed. The subclinical mastitis infection rates in the cows and quarters were 58.1% (25/43) and 25.6% (44/172), respectively. In the species identification, Staphylococcus aureus (40.9%) was the most prominent isolate, followed by S. chromogenes (22.7%), S. epidermis (18.2%), S. simulans (11.4%), S. haemolyticus (2.3%), S. muscae (2.3%), and S. xylosus (2.3%). In the antimicrobial susceptibility test, all isolates were 100% susceptible to 24 of 28 antibiotics, except for benzylpenicillin, cefalotin, cefpodoxime, and trimethoprim/sulfamethoxazole. The resistance rates of S. aureus, S. chromogenes, and S. muscae isolates to trimethoprim/sulfamethoxazole were 27.8%, 10%, and 100%, respectively, and the resistance rates of S. epidermis and S. xylosus to benzylpenicillin were 50% and 100%, respectively. S. chromogenes, S. epidermis, S. simulans, S. haemolyticus, and S. xylosus were resistant to cefalotin and cefpodoxime. In conclusion, restrictions on antimicrobial use for organic dairy farm certification have resulted in a high Staphylococcus spp. infection rate. Therefore, our study indicates the importance of mastitis management strategies implemented by farmers together with veterinary practitioners, even if mastitis does not appear clinically in organic dairy farms.

Application of Self-organizing Mapping-Random Forest Model to Map Landslide Susceptibility in Zigui Basin, Three Gorges Reservoir Region, China

( Changdong Li ),( Jingjing Long ),( Zhiyong Fu ),( Wenqiang Chen ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The Zigui basin is one of the most landslide-prone areas where thousands of landslides are distributed. Researches show that areas sharing the same conditions as identified landslides are clearly potential areas for future disasters. Performing the landslide susceptibility mapping is a heated issue in the area. Continued improvements in high-resolution satellite images, and the developments of unmanned aerial vehicles (UAVs) and site-investigation function well in constructing effective, high-quality landslide databases. GIS technology and machine learning algorithms have been widely applied in landslide susceptibility prediction. Whereas, whether the random and subjective selection of the landslides or non-landslides grid cells are reasonable in research of landslide susceptibility mapping is the existence problem. Based on the Two step cluster (TSC) algorithm and the Self-organizing mapping - Random forest (SOM-RF) model, a novel hybrid model is proposed to overcome the above drawbacks. SOM is used to produce a preliminary landslide susceptibility mapping. TSC algorithm is applied in telling apart the most reasonable True-Positive (TP) from recorded landslide grid cells in high-susceptibility zones and the False-Positive (FP) in low-susceptibility zones. Afterwards, the labeled datasets are imported into the RF model for training. And then the trained SOM-RF model is utilized to perform an improved landslide susceptibility mapping. Most areas with high or very high susceptibility are located within the hydro-fluctuation belt of the TGR. Compared with the susceptibility mapping produced by single RF model, the results of SOM-RF model demonstrate to have the superior prediction skill and higher reliability.

Bacteroides fragilis 군 세균의 cefepime 등 항균제에 대한 감수성

신정원,박남재,이경원,정윤섭,조장환 대한화학요법학회 1998 대한화학요법학회지 Vol.16 No.1

목적 : Bacteriodes fragilis군 (BFG) 세균은 일상 검체에서 흔히 분리되며 여러 가지 항균제에 내성인 균주가 많아 문제이다. 본 연군에서는 BPG 세균의 항균체 내성 양상 및 최근 개발된 제4세대 cephalosporin인 cefepime의 항균력을 알아보고자 하였다. 방법 : 1995년 1월부터 1996년 12월까지 신촌 세브란스병원 환자의 각종 임상 검체에서 분리된 BFG 세균 중 136주, 즉 B, fragilis 88주, B. thefaiotaomicron 28주, B. ovatus 7주, B uniformis 7주, B. distasonis 4주 및 B. vulgatus 2주를 대상으로 하였다. 항균제 감수성은 NGGLS 한천희석법으로 시험하였는데 시험세균을 항균제를 넣은 Wilkins Chalgren 한천에 접종하여 혐기성 상자에 48시간 배양한 후 판독하였다. 결과 : BFG 세균의 cefotaxime에 대한 내성율은 33-82%였다. Cefotetan에 대해서는 B. fragilis의 9%가 내성이었으나, B. thetaiotao micron은 79%, 그리고 다른 BFG 세균은 85%가 내성으로 B. fragilis 이외의 BFG 세균의 10%가 cefoxitin에 내성이었다. Cefepime의 MIC_(50)는 모든 BFG 균종에 대해 >128 ㎍/mL이었으며, 내성 균주의 비율도 85-100%로 높았다. Imipenem, chloramphenicol 및 metronidazole에 대한 내성인 균주는 없었다. 결론 : 국내에서 분리된 BFG 세균 중 제3세대 cephalosporin과 cephamycin, 그리고 clindamycin에 대한 내성 균주의 비율이 외국에 비하여 현저히 높았고, 이전에 분리된 국내 균주에 비해서도 그 내성율이 점차 높아지고 있어 앞으로 이들 약제에 대한 통상적인 감수성 시험이 필요하며, 제4세대 cephaloporin인 cefepime의 경우에는 그 MIC가 매우 높아서 혐기성 세균 감염의 치료약재로서는 유용하지 않다는 결론을 얻었다. Background : Bacteroides fragilis group (BFG) organisms, the most commonly isolated anaerobes from clinical specimens, are more frequently resistant to antirmcrobial agents than other anaerobes. The aim of this study was to determine the susceptibility of BFG organisms to various antimicrobial agents including cefepime. Methods : Antimicrobial susceptibility of 136 BFG organisms, whch were isolated in 1995 and 1996 from various clinical materials and consisted of 88 B. fragilis, 28 B. thetaiotaomicron, 7 B. ovatus, 7 B. miformis, 4 B. distasonis. 2 B. vulgatus, were tested by the NCCLS agar dilution method using Wilkins Chalgren agar. The plates were incubated in an anaerobic chamber for 48 h before reading the results. Results : The resistance rates to cefotaxime were 3382% depending on the species. The resistance rates to cefotetan varied markedly dependmg on the species of the BFG organisms and the resistance rates were 9% for B. fragilis. 79% for B. thetaiotaomicron and 85% for other BFG species. The resistance rates were higher than those in 1994. The resistance rates to cefoxitin were: B. fragilis. 1% ; B. thetaiotaomicron, 14%; other BFG species, 10%, although no isolate showed resistance to cefoxitin in 1994. The MIC90S of the cefepime were >128 ㎍/mL against all BFG organisms, and the resistance rates were 85-100%. No lsolates were found to be resistant to imipenem, chloramphenicol and metronidazole. Conclusion : The increased resistance to cefotaxhe, cephamych and chdarnycun indicates that routine antimicrobial susceptibility test of these drugs is needed before using the drugs, and the high MIC value to cefepirne suggests that it would not be useful for the treatment of anaerobic infection.

Evaluation of PM₁₀, CO₂, airborne bacteria, TVOCs, and formaldehyde in facilities for susceptible populations in South Korea

Hwang, Sung Ho,Roh, Jaehoon,Park, Wha Me Elsevier 2018 Environmental pollution Vol.242 No.1

<P><B>Abstract</B></P> <P>Poor indoor air quality can have adverse effects on human health, especially in susceptible populations; however, few studies have measured multiple pollutants in facilities for susceptible populations at a national scale in South Korea. Therefore, we measured the concentrations of indoor pollutants (fine particulate matter (PM<SUB>10</SUB>), CO<SUB>2</SUB>, airborne bacteria (AB), total volatile organic compounds (TVOCs), and formaldehyde) to determine their possible relation to other indoor environmental factors and characteristics of facilities with susceptible populations, such as hospitals, geriatric hospitals, elderly care facilities, and postnatal care centers throughout South Korea. Indoor pollutants were sampled at 82 indoor facilities, including 62 facilities for susceptible populations. Spearman's correlation, Kruskal–Wallis, and Mann–Whitney analyses were used to examine the relationship among and differences between pollutants at indoor facilities and indoor/outdoor differences in PM<SUB>10</SUB> concentration. There were significant correlations between indoor temperature and AB concentration (<I>r</I> = 0.37, <I>p</I> < 0.01), TVOCs, and formaldehyde (<I>r</I> = 0.264, <I>p</I> < 0.01). Indoor PM<SUB>10</SUB> concentrations were higher than outdoor concentrations at all facilities for susceptible populations (<I>p</I> < 0.01). CO<SUB>2</SUB> might be a good indicator for predicting indoor pollutants when categorized into two levels (≤750 ppm and >750 ppm). The hazard quotient of formaldehyde was higher than the acceptable level of 1 for children under the age of eight in postnatal care centers, indicative of unsafe levels. Therefore, more depth study for exposure characteristics of formaldehyde and indoor air quality (IAQ) in postnatal care facilities as a national scale is needed for finding the children exposure levels.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We assessed indoor air quality in facilities for susceptible populations in Korea. </LI> <LI> Indoor air temperature was correlated with AB, TVOC, and formaldehyde concentration. </LI> <LI> A CO<SUB>2</SUB> threshold of 750 ppm could be a good indicator of indoor air pollutants. </LI> <LI> The hazard quotient of formaldehyde was >1 for children in postnatal care facilities. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Indoor PM<SUB>10</SUB> concentrations were higher than outdoor concentrations in all facilities for susceptible populations. Overall, CO<SUB>2</SUB> might be a good indicator for predicting indoor pollutants when categorized into two groups: ≤ 750 ppm and >750 ppm.</P> <P>[DISPLAY OMISSION]</P>

돼지 다발성장막염 및 관절염(glässer씨병)의 원인균 조사 및 분리균의 병발성에 관한 연구

석호봉(Ho Bong Seok),이관형(Kwan Hyeong Lee),이난주(Ran Ju Lee),예재길(Jae Gil Yeh) 한국예방수의학회 1993 예방수의학회지 Vol.17 No.1

Investigation into the bacteriology and epidemiology features of polyserositis and polyarthritis(Glässer disease) were carried out at 13 intensive pig farms of Chungnam and Kyounggi areas. Also determined were isolated frequency of hemophilus-like organisms in various sources of pigs, antibiotics susceptibilities of the isolates and pathogenesis of guinea pigs experimentally infected with isolates. The results obtained were summarized as follows: 1. Out of 75 hemophilus-like organisms isolated from 13 pig farms, 13 isolates of them were showed in same biological properties with standard strains. 2. Hemophilus-like organisms isolated from various samples of pigs belonged to 53 of 238 nasal discharges(22,3% ), 9 of 97 lungs(9.3%), 8 of 79 thoracic fluids(10.1%) and 1 of 22 others(4.6%), respectively. Urease-negative strains isolated from 6 of nasal discharge and 7 of lung (plus 5 strains from Bayer). 3. In regional distribution of 85 hemophilus-like organisms, the isolating rates of Pyeongtaek(26.3%) and Gongju(25%) were higher than that of Cheonan(17.5%), Hongseong(5.7%) and Asan(5%). Urease negative strains isolated from piggeries of Pyeongtaek(5), Asan(2) and Gongju(1) areas. 4. Among 13 farms, 9 farms were affected within the limits of 4.1%-47.2%, which the rates was decreased in good managing status, while increased in poor status or in respiratory symptoms. 5. The prevalence of isolates in four weeks of age pigs(31%) were the highest, in five weeks(22.5%) to in eight weeks(22.2%) to next higher ranks but lower in four weeks less(9.3%) and in eight weeks above(8.9%). 6. All isolates were highly susceptible to chloramphenicol, cephalothin, ampicillin, although they were highly resistant to streptomycin, neomycin, kanamycin. The drug susceptible properties against strains isolated from Japanese and Korean were showed in similar results. 7. The similar results of the pathological symptoms, bacteriological recovery and anatomic lesions after injection experimentally in guinea pigs with two urease-negative isolates and one Japanese strain(HPS) were discussed. The gross pathological finding of pig cases occurred naturally in pig farms was finally observed.

2차 병원에서의 지역 사회 획득 요로 감염의 원인균 및 항생제 감수성 분석

조윤주,이은정,은영민,유황재,김철홍,이현희,김병길,최경민 대한소아감염학회 2010 Pediatric Infection and Vaccine Vol.17 No.1

Purpose:We investigated the causative organism and its antibiotic susceptibility of community acquired urinary tract infection (UTI) in children at a secondary hospital to test the adequacy of the current guidelines. Methods:Children diagnosed with UTI at the Department of Pediatrics, Kwandong University Myongji Hospital by pyuria and bacterial growth of greater than 1.0×105 CFU/mL on clean catch midstream urine from January 2005 to December 2008 were studied retrospectively. The epidemiologic data, causative organism, and the antibiotic susceptibility were analyzed. Results:Sixty two children were diagnosed with sixty four cases of UTI’s. Two bacteria were isolated in one case and thus data on 65 urine cultures were analyzed. The male:female ratio was 1.6:1 and 78.1% were less than 12 months of age. Escherichia coli was the predominant cause consisting of 53 cases (82.8%) of the cases. K. pneumoniae (5), Enterobacter (4), Enterococcus (1), ß-streptococcus (1), Diphtheroides (1) were isolated. The antibiotic resistance of E. coli were as follows; ampicillin 69.8%, cefotaxime 1.9%, gentamicin 15.1%, amikacin 0.0%, levofloxacin 1.9%, and trimethoprim/sulfamethoxazole 26.4 %. Only one case of the E. coli was extended spectrum β-lactamase (ESBL) positive. Conclusion:Compared to prior reports from other tertiary hospitals in Korea, E. coli was the predominant cause in childhood UTI and the rate of ESBL positivity was low. The antibiotic resistance was also different compared to prior reports. We conclude that a difference in the cause and antibiotic resistance of childhood UTI exists between centers and this should be taken into consideration when prescribing antibiotics for childhood UTIs. 목적:소아 요로 감염은 가장 흔한 세균성 질환의 하나로, 특히 요로계의 해부학적 기형Table 1. Difference in Antimicrobial Sensitivity of Urinary Tract Infection of E. coli between Hospitals Antimicrobials Susceptibility(%)Myongji Hospital*Kim, et al., 20043)†Lee, et al., 200512)Kang, et al., 200415)Ampicillin Cefotaxime Gentamicin Amikacin Levofloxacin TMP-SMX‡Levotriaxone Ceftazidime Tobramycin Imipenem Cefoxitin Cefepime Aztreonam Cefazolin 30.298.184.910098.173.6 886696 967374 9393 27.8 74.196.3 59.394.8 79.698.196.394.492.688.916.9 95.8 42.695.991.862.7 *Extended spectrum β-lactamase(ESBL) producing E. coli is detected in only 1 case (0.16%)†ESBL producing E. coli is detected in 13 cases (17.56%). ‡trimethoprim/sulfamethoxazole 이 동반되면 재발하기 쉽고, 치료가 되지 않을 경우 고혈압, 신부전, 말기 신질환 등을 초래할 수 있다. 따라서 조기 진단과 적절한 치료 및 반복 감염의 예방이 중요한데, 이를 위해서는 정확한 원인 균주의 파악이 선행되어야 한다. 이에 저자들은 지역사회를 기반으로 하는 2차 병원에서 진단되는 소아요로감염의 원인균 및 항생제 감수성을 조사하여 적절한 항생제 선택에 도움이 되고자 본 연구를 시행하였다. 방법:2005년 1월 1일부터 2008년 12월 31일까지 관동대 명지병원 소아과에 입원하여 농뇨(WBC>5/HPF) 와 요배양검사 상 1.0×105 CFU/mL 이상의 배양검사 결과를 보인 환아를 대상으로 소변 검사, 소변 배양 검사 소견, 항생제 감수성 결과, 방사선 소견 등의 검사 결과를 의무 기록을 통해 후향적으로 조사하였다. 결과:국내 3차 기관 등에서의 보고와는 다르게 대부분의 요로감염은 E. coli에 의한 것이었으며 ESBL 생성균주 또한 낮게 나타났다. 1) 전체 환아 62명의 평균 연령은 20개월이었으며, 1세 미만에서 호발(50명, 78.1%)하였다. 전체 환아 62명의 남녀 비는 1.6:1이었고, 1세 미만에서는 2.6:1, 1세 이상에서는 1:3.7이었다. 2) 전체 62명의 소변 배양 검사에서 분리된 균주는 E. coli가 가장 많았고(53명, 82.8%), K. pneumoniae (5명, 8.1%), Enterobacter (4명, 6.5%) Enterococcus, β-streptococcus, diphtheroides 각각 (1명, 1.6%) 순이었다. 3)E. coli의 항생제에 대한 감수성은 ampicillin 30.2 %, cefotaxime 98.1%, gentamicin 94.9%, amikacin 100%, levofloxacin 98.1%, trimethoprim/sulfamethoxazole 73.6%의 결과를 보였으며, 이 중 ESBL 생성균주는 1주가 검출되었다. 최근 3차 병원에서 실시한 감수성 결과와 차이를 보이는 것으로 의료기관에 따라 항생제 내성율의 차이가 있음을 시사하는 결과로 생각되며, 이는 일차 항생제 선택에 있어 지역별, 병원별 차이를 시사하는 것으로 생각할 수 있다. 결론:향후 요로 감염 원인균 및 항생제 감수성에 대한 기관별, 지역별 지속적인 조사가 필요할 것으로 사료되며, 이에 기반한 적절한 항생제 사용이 요구된다.

세균의 항생제 감수성 변화의 추이 : 1986년-1993년 결과

김구엽,이희주,서환조 대한감염학회 1995 감염 Vol.27 No.2

배경:지난 수년간 항생제 내성균주의 출현이 증가되어 왔으며, 이로인해 경험적으로 항생제 사용시 올바른 약제 선택을 위해 각각의 항생제에 대한 항생제 내성균주의 비율을 이해하는 것이 중요하리라고 사료된다. 이에 저자등은 다음과 같은 연구를 시행하였다. 방법:1986년부터 1993년까지 8년간 경희의료원 외래 및 입원환자에서 분리, 동정된 균주를 대상으로 항생제 감수성을 조사하였다. 결과 1)8년간의 조사 기간 동안 그람 양성 균주 중에는 S.aureus, Coagulase-negive staphylococcus, Streptococcus, Enterococcus 순으로 많았고, 그람 음성균주 중에는 E.coli, Pseudomonas, K.pneumoniae, Serratia, Acinetobacter, Enterobacter, Proteus 순으로 많았다. 2)1986년과 1993년을 비교하면 모든 균주의 항생제 내성비율이 증가하고 있었다. 결론:일부 균주는 항생제 감수성이 매우 높으므로 경험적 선택이 가능하지만, 일부 균주는 급속한 내성 균주의 출현이 계속되고 있으므로 항생제 선택시 감수성 검사후 사용하는것이 내성 균주의 출현을 줄일뿐아니라 경제적 손실및 환자의 이환율을 줄이는데 기여할 것이다. Background: During the past several years, the frequency and spectrum of antimicrobial resistant infections have increased in both hospitals and the general community. Therefore, it is important to understand exactly the changing patterns of antimicrobial resistant strains for the empirical selection of antimicrobial agents. Methods: We analyzed the antimicrobial susceptibility patterns at Kyung Hee Medical Center, during the years 1986-1993. Result: 1)The most frequently isolated strains of Gram-positive organism were Staphylococcus aureus, Coagulase-negative staphylococcus, Streptococcus and Enterococcus fecalis, and the most frequently isolated strains of Gram-negative organisms were E.coli, Pseudomonas, Klebsiella, Serratia, Acinetogbacter, Enterobacter and Proteus. 2)Antimicrobial resistance of all organisms has incleased as of 1993 compared to 1986. Conclusion: The empirical selection of antibimicrobial agents for some strains is possible when they show high sensitivities to the drugs. However, as antimicrobial resistances of some strains are rapidly increasing, antimicrobial susceptibility test is necessary for the appropriate selection of antimicrobial agents. This will contribute to the reduction of resistant strains, health-care costs, and morbidity.