• Journal of Microbiology
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• 제45권6호
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• pp.590-592
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• 2007

We report the isolation of Salmonella enterica serotype Typhimurium phage type DT104 (CCARM 8104) from swine in Korea. The CCARM 8104 isolate was resistant to nalidixic acid and showed reduced susceptibility to quinolones. The CCARM 8104 isolate had a missense mutation, Asp87Asn, in the quinolone resistance-determining region in gyrA and produced PSE-1. The CCARM 8104 isolate carried two different class 1 integrons, and the PSE-1 ${\beta}$-lactamase gene was inserted into a 1,200 bp class 1 integron. The presence of DT104 with pse-1 in an integron located in a plasmid and reduced susceptibility to quinolone in swine pose a significant threat of possible horizontal spread between swine and humans.

• 환경생물
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• 제23권4호
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• pp.390-397
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• 2005

The inhibition of cell recovery might be proceeded via either the damage of the mechanism of the recovery itself or via the formation of irreversible damage which could not be repaired at all. Both these processes may take place at the same time. Any of these possibilities would result in a decrease in both the rate and extent of cell recovery. To distinguish them, a quantitative approach describing the process of recovery as a decrease in the effective radiation dose was applied to experimental data on the recovery from potentially lethal damage in Chinese hamster cells exposed to X-rays alone or combined with various chemicals (pyruvate, novobiocin, lactate, nalidixic acid, 3-aminobenzamide). For these particular cases, it is concluded that the recovery process itself is not damaged and the inhibition of the recovery is entirely due to the enhanced yield of the irreversibly damaged cells.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1992년도 제1회 신약개발 연구발표회 초록집
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• pp.17-17
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• 1992

항균성 물질을 이용한 화학 요법의 역사는 1930 년대 초 술폰아미드의 발견으로부터 비롯되었고, 페니실린의 발견 이래 $\beta$-lactam 계 항생제가 주종을 이루고 있다. 1963년 Lesher 와 Gruett 에 의해 합성된 nalidixic acid 가 요도염 치료제로 임상에 사용된 이후 이와 유사한 구조를 갖는 항균제 개발에 많은 연구가 진행되어 제 1세대, 제 2세대의 quinolone 개발에 이어 1950년대에 들어 제 3세대 quinolone의 개발이 활발히 진행되어 왔다. 제 3세대 항생제는 C-6 위치에 F기를 도입한 것으로 연구의 진행 방향은 항균력의 향상과 체내에서의 지속 시간의 연장, 경구 투여시 흡수로의 증가와 독성의 약화를 위한 것이다. 본 연구는 quinolone의 기본 골격을 유지하면서 C-7 위치에 새로운 group을 도입하여 그에 대한 항균력을 측정하여 새로운 quinolone계 항생제의 개발을 시도하였다.

• 한국환경농학회지
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• 제20권5호
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• pp.330-334
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• 2001

The polymorphism of Azospirillum isolates from ornamental rhizosphere and two reference strains were examined with respect to intrinsic antibiotic resistance (IAR) profile. All the isolates showed different intrinsic resistances to different antibiotics viz., tetracycline, kanamycin, nalidixic acid, streptomycin, ampicillin, spectinomycin and chloramphenicol. All the strains demonstrated susceptibility to high concentration of all antibiotics used in the present experiment. In addition to these general patterns, we also obseved the multiple antibiotic resistances of Azospirillum strains. The Azospirillum sp. OAD-11 was resistant to tetracycline, streptomycin and ampicillin, and Azospirillum sp. OAD-57 was resistant to tetracycline and streptomycin. Conversely, Azospirillum sp. OAD-9 possessed the dual susceptibility to tetracycline and spectinomycin, whereas Azospirillum sp. OAD-37 was dual susceptible to streptomycin and kanamycin. Such multiple antibiotic resistant/susceptible traits could be useful for the identification of the strains in field experiments or in molecular genetic transfer experiments.

• 한국환경보건학회지
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• 제33권1호
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• pp.16-20
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• 2007

Vibrio parahaemolyticus was investigated for analysis of distribution and antibiotic susceptibility at the markets, Seoul in 2004. The average isolation rate was 26.8%(306/1,143) and the highest rate with 64.9% was obtained in August. The isolation rates from December to April was 0.0%. It is more effective to inoculate into the enrichment medium, alkaline pepton water by swabbing a sample with a cotton ball rather than pouring mixed sample. The isolation rates were from 24.4% to 37.1% in domestic samples and from 9.8% to 26.8% in imported ones. All of the isolates were resistent to ampicillin and ticarcillin and most of them were sensitive to chloramphenicol, tetracycline, nalidixic acid, amoxicillin, ceftriaxone, streptomycin, kanamycin, trimethoprim/sulfamethoxazol, ampicillin/sulbactam, ciprofloxacin.

• 한국동물위생학회지
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• 제38권2호
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• pp.95-100
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• 2015

An investigation was carried out to determine the prevalence and antimicrobial resistance of Salmonella isolated from chicks and ducks. A total of 2,522 samples collected from 281 farms were examined from 2013 to 2014. The overall prevalence of Salmonella spp. was 21.7% (61/281) of farms and 83 isolates (3.3%) were isolated from 2,522 samples. Nine serotypes of Salmonella spp. were identified such as S. Typhimurium (19/83), S. Enteritidis (12/83), S. London (11/83), S. Senftenberg (8/83), S. Infantis (4/83), S. Montevideo (3/83), S. Hadar (3/83), S. Saintpaul (1/83), S. Rissen (1/83) and S. Arizonae (2/83). Nineteen isolates were found to be untypable serotypes. In the results of antimicrobial resistance test, all of isolates were resistant to at least two antimicrobial agent and the high resistance was found to nalidixic acid (66.3%), streptomycin (57.8%). All of isolates were susceptible to amoxacillin/clavulic acid, cefeprime, ampicillin, sulfamethoxazole/trimethoprim. This results indicated the serotypes of Salmonella isolates are widely distributed in chicks and ducks. Therefore further epidemiological studies should be carried out in breeder farm and a hatchery.

• 환경생물
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• 제29권4호
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• pp.286-295
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• 2011

Bacteria resistant to various antibiotics have recently become an issue of the utmost importance. Resistant strains are not uncommon, even in municipal drinking water sources. The health threat posed by resistant, pathogenic bacteria has serious ramifications for both public health and agriculture. In this study, we isolated antibiotic resistant bacteria from water samples from the Han River, Korea, which is contaminated by the wastewater from many industrial complexes, hospitals, agricultural and animal husbandry estates, and from wastewater treatment facilities. We determined the degrees of resistance to various antibiotics exhibited by the isolated strains. The similarities between the isolated $E.$ $coli$ strains were examined, using the pulsed field gel electrophoresis and multilocus sequence typing, in order to trace their origins and to explore the syntechnic adaptations and pathogenicity of the various strains and relate these to their genetic sequence. A total of 25 $E.$ $coli$ strains were isolated from six stations along the Han River. All the 25 strains exhibited resistance to ampicillin. We also investigated resistance to amoxicillin, clavulanic acid, cefazolin, cofoxitin, cefotaxime, cefpodoxime, ceftriaxone, cefepime, nalidixic acid, aztreonam, ciprofloxacin, streptomycin, gentamicin, chloramphenicol and imipenem. Based on the ESBL detection, 14 strains belonged to the ESBL producing strains. The number of the clonal complex producing strains was 5 among the 14 isolated strains. The 5 strains were included in the 168, 23, 38, 469, 156 clonal complex, respectively. The rest 9 strains were not included in the clonal complex, but showed independent STs.

• 한국동물위생학회지
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• 제33권1호
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• pp.51-57
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• 2010

Salmonella Typhimurium is a virulent pathogen for human and animal. We studied serotypes, biochemical characteristics, and antimicrobial resistance of S. Typhimurium isolated from diseased pigs in Gyeongbuk province over 1998 to 2008. One hundred sixteen isolates were identified as S. Typhimurium by biochemical characteristics and serotypes from 90 farms. The biochemical characteristics of S. Typhimurium isolates was production of $H_2S$, indole-negative, fermentation of mannitol, dulcitol, sorbitol, inositol, rhamnose, and maltose, and ornithine decarboxylase. At antimicrobial susceptibility test, the majority of isolates were highly susceptible to amoxicillin/clavulanic acid, cefepime, ciprofloxacin, while were highly resistant streptomycin, cephalothin, enrofloxacin, nalidixic acid, apramycin, chloramphenicol, tetracycline. The isolates were divided into 65 resistant patterns and 47 of the isolates were shown as a DT104 ASSSuT resistant phenotype.

• Bulletin of the Korean Chemical Society
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• 제21권9호
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• pp.849-854
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• 2000

The protonation and divalent cation complexation equilibria of several quinolone antibiotics such as nalidixic acid (NAL),flumequine (FLU), oxolinic acid (OXO), ofloxacin (OFL), norfloxacin (NOR) and enoxacin (ENO) have been examined by potentiome tric titration and spectrophotometric method. The antibacterial activity of these drugs depends upon the pH and the concentration of metal cations such as Mg2+ , Ca2+ in solu-tion. The apparent ionization constants of NAL, FLU, OXO, OFL, NOR and ENO in aqueous solution were found to be 6.33, 6.51, 6.72, 7.18, 7.26, and 7.53, respectively. In aqueous solution, NAL, FLU and OXO were found to be present mainly as two chemical species : molecularand anionic; but OFL, NOR and ENO were present mainly as three chemical species : anionic, neutral zwitterionic and cationic form, in equilibrium. The pKa1 and pKa2are found to be 6.10 and 8.28 for OFL; 6.23 and 8.55 for NOR; 6.32 and8.62 for ENO, respec-tively. The complex formation constants between OFL, NOR or FLU and some divalent cations are measured at pH 7.5. The 1 : 1 complexes are formed mainly by ion-dipole interaction. FLU has somewhat larger Kf values than OFL and NOR because its molecular size is small and the FLU is present asanionic form at pH 7.5.

• 대한미생물학회지
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• 제14권1호
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• pp.27-37
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• 1979

1978년(年)에 분리(分離)한 9주(株)의 Shigella, 70주(株)의 Salmonella paratyphi A 및 230주(株)의 S. typhi의 약제내성(藥劑耐性), 내성화방지(耐性化防止) 및 제거(除去)에 대(對)하여 실험(實驗)하여 다음과 같은 성적(成績)을 얻었다. Shigella는 79주(株)가 Sh. flexneri, 16주(株)가 Sh. sonnei였는데 1주(株)를 제외(除外)한 94주(株)가 chloramphenicol tetracycline, streptomycin, sulfisomidine에 다약제내성(多藥劑耐性)이었으며 그중(中) 70주(株)는 ampicillin과 carbenicillin에, 80주(株)는 trimethoprim-sulfamethoxazole에, 22주(株)는 nalidixic acid에, 1주(株)는kanamycin에도 내성(耐性)이었다. Gentamicin, amikacin, cephaloridine, rifampin에 내성(耐性)인 균주(菌株)를 없었다. S. paratyphi A와 S. typhi는 공시약제(供試藥劑)에 감수성(感受性)이었으나 다만 rifampin, 또는 sulfisomidine에 약(弱)한 내성(耐性)을 가진 것이 있었다. 다약제내성(多藥劑耐性)인 shigella의 약(約) 80%가 전달성(傳達性) R plasmid를 가지고 있어서 그 내성(耐性)을 E. coli에 전달(傳達)시킬 수 있었다. 내성전달빈도(耐性傳達頻度)는 공시균주(供試菌株) 및 피전달균(被傳達菌)에 따라 차이(差異)가 있었다. 보존(保存)한 내성균주(耐性菌株)는 그 비율(比率)은 균주(菌株)에 따라 차이(差異)가 있으나 내성균(耐性菌)과 감수성균(感受性菌)으로 구성(構成)되어 있었으며 계대배양(繼代培養)에 의하여 내성(耐性)이 쉽게 탈락(脫落)되지는 안하였다. Acriflavine은 내성(耐性)을 탈락(脫落)시키는 효과(效果)는 있었으며 균주(菌株)에 따라 그 차이(差異)가 심(甚)하였고 atabrine은 효과(效果)가 없었다. 약제(藥劑)의 병용(倂用)은 Shigella에 대(對)한 작용(作用)을 증강(增强)시키는 경우(境遇)가 많으며 대체(大體)로 상승작용(相乘作用)을 나타냈고 상가작용(相加作用)을 나타내는 경우(境遇)가 있었으나 길항작용(拮抗作用)은 볼 수 없었다.