• Korean journal of applied entomology
• /
• v.24 no.1 s.62
• /
• pp.19-24
• /
• 1985

Alternaria mali isolated from infected apples in storages and orchards of the four main apple growing areas of Taegu, Yesan, Jungup and Chungju in Korea was tested with various fungicides added in PSA medium. The fungal tolerance varied with little difference by orchard area and with great difference by king and concentration of fungicide. Minimum inhibitory concentration (MIC) of chlorothalonil and captafol was $100,238{\mu}g\;and\;81,000{\mu}g/ml$, respectively, showing low effects with high fungal tolerance; of iprodione and folpet was $3,285{\mu}g\;and\;3,000{\mu}g/ml$, respectively, showing moderate effects with moderate fungal tolerance; and of oxidong, polyoxin and polydong was $1,000{\mu}g,\;900{\mu}g\;and\;500{\mu}g/ml$, respectively, showing high effects with low fungal tolerance. Mycelial growth, conidia formation and conidia germination of the fungus showed a similar trend of response to the seven fungicides.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.6
• /
• pp.927-932
• /
• 1994

A total of 34 Salmonella sp. an d25 Shigella sp. were isolated from 311 patients with diarrhea. The isolation rates of Salmonella sp. ad Shigella sp. were 10.9% and 8%, respectively. The serogroups of 34 Salmonella sp. were in order of group D(50%), group B(38.25), group E(8.8%) and group C 92, 9%0. the serogroups of 25 Shigella sp. were group D(96%) and group B(4%). Seasonal distribution of isolated Salmonella sp. and Shigella sp. were shown the most high at July, 17.65% and 64%, respectively. Age group distribution of isolated Salmonella sp. and Shigella sp. were shown the most high at twenties and thirties (23.5%), and teens(76%), respectively. The Salmonella isolates were resistant in order of prevalence use of streptomycin(SM) (100%), erythromycin (EM) and movobiocin (NB)(90.6%), penicillin G(PG) (65.6%) and cephalexin (CPX)(46.9%). the isolates of Shigella sp. were resistant in order of prevalence use of EM (95.8%), NB(91.7%), SM(87.5%). Eighteen kinds of resistant patterns of Salmonella ioslates were detected. The multiple resistance patterns of Shigella isolates were mostly SM, EM, NB type (79.2%). The minimum inhibitory concentration of Salmonella sp. and Shigella sp. and Shigella sp. isolated from patients with diarrhea were tabulated.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.5
• /
• pp.3315-3322
• /
• 2015

Staphylococcus aureus is the major causative organism of nasocomial infection being the important pathogen in the clinic. Appearance of staphylococcus aureus resistant to methicillin (MRSA) is becoming a big problem in clinics and dynamics all over the world acquiring antibiotic resistance with virulence factors as its feature differentiated from other pathogenic bacteria fast. This research intended to compare and analyze the correlation of antibiotics resistance between strains with toxin genes and distribution of toxin genes of MRSA 101 strains acquired from clinical specimen in one general hospital (enterotoxin(se), toxic shock syndrome toxin-1(tst), exfoliative toxin(et), Panton Valentine leukocidin(pvl)). seg gene, isolated the most among toxin genes, was detected in 59 strains (58.4%) and more than two toxin genes were detected in 70 strains (69.3%). As a combination possessing toxin genes, it was detected in 19 strains (18.8%) as seb, sec, seg, sei, tst and the second frequent combination was sec, seg, sei shown in 11 strains (10.9%). 19 strains (18.8%) with combinations of toxin genes same with seb, sec, seg, sei, tst had 100% resistance Ampicillin, Benzylpenicillin, Ciprofloxacin, Clindamycin, Gentamicin, Erythromycin, Telithromycin, Tetracycline antibiotics. Strains with many toxin genes showed high correlation of antibiotic resistance. Afterwards, effective therapy and thorough infection management should be preceded not to spread the resistance of MRSA strain.

• Pediatric Infection and Vaccine
• /
• v.4 no.2
• /
• pp.218-224
• /
• 1997

Purpose: The antimicrobial resistance of S. pneumoniae has encountered with increasing frequency from around the world. In our country, penicillin resistant strains of S. penumococci are rapidly increasing. It has been known that colonized pneumococci in upper respiratory tract cause sinisitis, otitis media, meningitis and pneumonia. We tried to reveal the colonization rate of pneumonocci in upper respiratory tract, their antimicrobial resistance and DNA fingerprinting pattern in normal children. Methods: We got specimens from 117 children of day-care center in Seoul through oropharyngeal swab. After incubation on BAP, optochin test and slide latex agglutination test were used for identification. Antimicobial susceptibility test to penicillin, vancomycin, erythromycin and TMP-SMZ was done with disk diffusion method. Penicillin MIC was gotten through the broth microdilution method. Genotyping of 45 pneumococci was done by rep-PCR using REP1R-Dt and REP2-Dt primer. Results: The carriage rate of pneumococci in the day-care center children was 38%(45/117). The resistance of penicillin, erhthromycin, TMP/SMZ, vancomycin by the disk diffusion method are 89%, 91%, 64% and 0%, respectively. 64% of the isolates showed multiple resistance. 7 types of DNA fingerprinting were gotten and 78% of isolates belonged to three types. Conclusion: We found that the antimicrobial resistance of children attending the day-care center in Seoul was much higher than expected. We assumed that this might be due to their easy and frequent exposure to antimicrobial agents and crowded day-care center environment.

• Journal of Veterinary Clinics
• /
• v.5 no.1
• /
• pp.53-59
• /
• 1988

한국 재래산양에 대한 L. monocytogenes균의 감염원을 조사하기 위하여 총 459개의 재래산양 분변, 비즙, 장기, 사료 및 토양재료로부터 균분리를 시도하였으며, 분리균의 항균성 물질에 대한 감수성 및 인공 감염시의 L. monocytogenes의 침입장기를 조사하였던 결과는 다음과 같다. L. monocytogenes는 분변에서만 분리되었으며 (분리율 8.2%) 분변이 본균의 주요 감염원으로 인정되었다. 가검재료로부터 L. monocytogenes의 분리방법으로는 유제화 재료를 혈액배지로써 37에서 24～48시간 동안 호기배양함이 우수하였다. 분리된 L. monocytogenes 8주 중 100%의 균주가 amikacin, colistin, tanamycin, neomycin에 내성을 나타내었으며, clinmycin, gentamicin, lincomycin, methicillin 및 refampin에 87.5%, ampicillin및 oles-ndomycin에 75.0%, Chloramphenico에 62.5%, tetracycline에 50.0% 및 cephalot hin에 37.5%의 균주가 내성이었다. Nitrofurantoin에는 전 균주가 감수성을 나타내었다. L. monocytogenes를 재래산양에 경구 및 정맥내로 접종하였을때 패혈증이 인정되었으며 대부분의 실질장기가 이 균의 침입부위인 것으로 관찰되었다.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1482-1483
• /
• 2006

고전압 방전시험 장치는 국제전기기술위원회 규격(IEC 61000-4-2)에서 규정하고 있는 콘덴서 방식을 사용하며, 매우 짧은 시간에 방전함으로서 펄스 형태의 방전전류가 통전된다. 이러한 정전기적인 방전에 의해 전자기기에 고장을 발생시키며 이를 검증하는 방법으로 정전기 내성시험법이 있다. 본 논문에서는 첫째로 방전장치가 발생하는 잡음 전계량을 측정하였고, 둘째로 방전장치를 시험시료에 근접하는 방법에 따른 시험시료에 미치는 영향을 실험을 통해 검증하였고, 셋째로 근접방법에 따른 정전유도 현상이 시험시료에 미치는 영향을 실험적으로 검증하였다. 이러한 세 가지 현상을 바탕으로 시험시료가 고전압 방전장치를 근접 방전하여 방전을 유발시켰을 때의 전자파의 영향에 내성을 갖고 있는지를 검증하는 새로운 시험방법을 제안하였다.

• Review of KIISC
• /
• v.33 no.2
• /
• pp.21-30
• /
• 2023

양자 컴퓨팅은 혁신적인 계산 패러다임으로, 큐비트를 사용하여 기존 슈퍼컴퓨터 상에서 복잡했던 문제들을 빠르게 해결할 수 있다. 다만 양자 컴퓨팅의 발전은 현대 암호의 보안성을 크게 위협함으로써 기존 암호화 시스템을 양자컴퓨팅에 안전한 암호화 시스템으로 전환하는 작업이 요구되고 있다. 현재 전세계 IT 기업들에서는 양자내성암호로의 전환과 관련하여 기존 암호 시스템과의 호환 그리고 새로운 암호의 보안성이라는 문제 해결을 위해 함께 연구 개발 중에 있다. 본 고에서는 양자컴퓨팅에 대비한 양자 내성 암호로의 전이 동향에 대해 조사하며 이와 관련된 문제, 전략 그리고 주요 고려 사항들에 대해 확인해 보도록 한다.

• Review of KIISC
• /
• v.34 no.2
• /
• pp.49-55
• /
• 2024

고전 컴퓨터에서 풀기 어려운 난제를 효율적으로 모델링하고 해결할 수 있는 양자 컴퓨터는 현재암호들을 위협하고 있다. 특히, 공개키 암호에 해당하는 RSA와 Elliptic Curve Cryptography (ECC)는 Shor의 양자 알고리즘에 의해 해당 암호들의 안전성이 기반이 되는 난제들을 다항 시간 내에 해결하여 새로운 양자 내성 암호가 필요한 상황이다. 이에 NIST는 양자내성암호 표준화 공모전을 주최함으로써 현재까지 표준화 작업을 이어나가고 있다. 대칭키 암호의 경우, Grover의양자 검색 알고리즘에 의해 고전 컴퓨터상에서 보장하던 보안 강도가 제곱근으로 감소되게 된다. 기존, 신규 암호 알고리즘 모두 양자 컴퓨터상에서의 보안 강도를 평가해야 되는 상황이며, 이에 NIST는 양자 후 보안 강도 기준을 도입하였다. 양자 후 보안 강도는 레벨 1에서 5로 정의되며, 각 레벨에는 AES 및 SHA-2/3에 대한 양자 해킹 비용이 지정되어있다. 본 논문에서는 이러한 암호 학계 상황에 따라, 대칭키 AES 및 해시 함수 SHA-2/3에 대한 해킹, 특히 양자 회로 구현 동향에 대해 살펴보고자 한다.

• Korean Journal of Microbiology
• /
• v.50 no.2
• /
• pp.101-107
• /
• 2014

Community-acquired antimicrobial resistant bacteria are an emerging problem world-wide. In Korea, resistant bacteria are more prevalent than in other industrialized countries. The aim of this study was to investigate the isolation frequency of methicillin-resistant staphylococci (MRS), Pseudomonas, and Enterobacteriaceae from surrounding environment (home, colleges, public transportation system and possessions) in Seoul, and to examine the level of drug resistance to 13 antimicrobial agents, which are in wide spread clinical use in Korea, as well as new agent, tigecycline in Enterobacteriaceae isolates. Of total 239 samples, 18 (7.5%) MRS, 10 (4.2%) Pseudomonas, and 30 (12.6%) Entarobacteriaceae were isolated. A total of 5 (2.1%) methicillin-resistant S. aureus (MRSA) were detected in home (2 samples), colleges (1 sample), and et cetera (2 sample). A total of 5 (2.1%) Escherichia coli were detected in in home (1 samples), public transportations (3 sample), and et cetera (1 sample). Resistance to cephalosporins, fluoroquinolones, carbapenems, ${\beta}$-lactams, tetracyclines, and aminoglycosides was found in 71.9%, 71.9%, 68.8%, 68.8%, 50.0%, and 25.0% of 32 Enterobacteriaceae isolates, respectively. Also, resistance rate to trimethoprim/sulfamethoxazole of the isolates was a 43.8%. Moreover, 59.4% of the isolates were resistant to new agent, tigecycline and resistance to all agents tested was observed in 3 isolates. Five E. coli isolates were resistant to most of the agents tested, but some of them were susceptible to ciprofloxacin and gentamicin. This study can serve as a data point for future comparisons of possible changes in antibiotic resistance levels in surrounding environment. And multilateral strategies for preventing the incidence and spread of antibiotic resistance are needed.

• Clinical and Experimental Pediatrics
• /
• v.45 no.3
• /
• pp.346-353
• /
• 2002

Purpose : Penicillin- and multidrug-resistant S. pneumoniae poses a serious threat to clinicians because the rate of resistance of S. pneumoniae to penicillin in Korea has surged up to the world's highest level. This study was performed to assess the carriage rate, serogroups and antimicrobial susceptibility of S. pneumoniae isolated from oropharynx in children. Methods : From March to July 1998, 209 children under 5 years of age were recruited from five day care centers. The carriage rate for pneumococci was obtained. Antimicrobial susceptibilities were determined with the E-test and agar dilution methods. Serogrouping was performed on 48 of the pneumococcal isolates by the Quellung reaction. Results : The carriage rate of S. pneumoniae was 30.1%. Antimicrobial susceptibility profiles were available for 59 of the isolates. Sixty-six percent of isolates were not susceptible to penicillin, and multidrug-resistance was observed in 76.3% of the isolates. A high proportion of the penicillin-resistant strains showed associated resistance to trimethoprim-sulfamethoxazole, tetracycline, erythromycin, and oxacillin. The most prevalent oropharyngeal serogroups were 19, 6, 3, 23, and 29. Resistance of the pneumococcal isolates to penicillin was different according to the serogroups. All of the strains of serogroup 19, 23, and 29 was resistant to penicillin but 87.5% of serogroup 3 strains were susceptible to penicillin. Conclusion : The resistance rate of S. pneumoniae isolated from oropharynx in children was very high to penicillin and other antimicrobial agents. For the reduction of the drug-resistant rate of S. pneumoniae, clinicians should be required to be more judicious in their use of antimicrobial agents.