• 한국미생물·생명공학회지
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• 제18권5호
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• pp.541-546
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• 1990

Bacillus sphaericus ts-D1290 치사돌연변이주의 특성을 연구하기 위하여 제한온도와 허용온도에서 생산하는 단백질의 차이점을 연구하였고, 모기유충에서 생산하는 단백질을 분리하여 모기유충에 치사되는지를 조사하였다. ts-D1290 균주를 $42^{\circ}C$에서 배양했을 때는 $30^{\circ}C$ 배양보다 균체의 단백질 함량이 약 1/5로 감소하였고, $42^{\circ}C$에서 4시간 배양후 $30^{\circ}C$로 배양하였들 때는 약 1/3로 감소하였다. 그리고 단백질 패천은 ts-D1290 균주를 $42^{\circ}C$에서 전배양 후 $30^{\circ}C$로 하강 배양하였을 때는 $30^{\circ}C$에서 전배야하여 $42^{\circ}C$로 상승배양하였을 때와는 달라 분자량 221kd 단백질이 나타나지 않았지만 분자량 150kd 단백질은 $30^{\circ}C$ 전 배양하였을 때와 같이 현저하게 나타났다.

• 대한미생물학회지
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• 제7권1호
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• pp.1-8
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• 1972

The authors made a study on the bacteriological identification about unidentified strains which were roughly screened by local health center, which an epidemic diarrhea was outbreak at Ham Yang Gun, Kyeongsang-Namdo in July 1971. And the authors made an attempt to bacteriological Identification, serotyping with slide agglutination, and determination of the susceptibility of identified strains to various chemotherapeutic agents. The results Were obtained as follows: 1. The isolated strains identified Shigella flexneri type 2b(2 strains) and Salmonella paratyphi B(4 strains). 2. Sensitivity test using with three concentrations chemotherapeutic agents(Paper disk used; Eiken chemical Co., Tokyo, Japan): (1) Shigella flexneri type 2b isolated strains were sensitive to kanamycin, colistin(100%) and penicllin(50%) respectively, but resistant to erythromycin, oleandomycin, leucomycin, chloramphenicol, tetracycline, dihydrostreptomycin and sulfadimethoxin(100%) respectively. (2) Salmonella paratyphi B isolated strains were sensitive to chloramphenicol, tetracycline, dihydrostreptomycin, kanamycin, sulfadimethoxine(100%) and colistin(50%) respectively, but resistant to penicillin, erythromycin, oleandomycin and leucomycin(100%) respectively. 3. Sensitivity test using with multodisk urinary code(Paper disk used; Oxoid, London): (1) Shigella flexneri type 2b isolated strains were sensitive to Bactrim, ampicillin, nitrofurantoin, nalidixic add and gentamicin(100%) respectively, but resistant to chloramhpenicol, tetracycline, sulfadiazine and Fanasil(100%) respectively. (2) Salmonell paratyphi B isolated strains were sensitive to Bactrim, chloramphenicol, ampicillin, nitrofurantoin, tetracycline, nalidixic acid, gentamicin(100%) and sulfadiazine(50%) respectively, but resistant to Fanasil(100%) and sulfadiazine(50%) respectively.

• 한국미생물·생명공학회지
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• 제15권5호
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• pp.319-327
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• 1987

알코올 생산성이 높은 Zymomonas 균주의 기질 이용성을 넓히기 위한 목적으로 natural replicon을 포함하며 적당한 항생제 저항표지를 갖는 plasmid vector의 제조를 시도하였다. Z. mobilis ATCC10988에서 분리된 몇 개의 plasmid중 3.9kb의 적당한 크기를 갖는 pZM3를 선정하여 수종의 제한효소로 처리하여 절편의 크기에 따라 유전자 지도를 작성하였다. pZM 3의 replicon과 pBR 325의 chloramphenicol 저항유전자를 포함한 재조합 plasmid인 pHZ22를 개발하고 이 plasmid vector가 숙주세포인 Z. mobilis ATCC31821에서 독립적으로 replication됨을 확인하였다. 또 하나의 항생제 저항표지로서 RP4의 tetracycline 저항유전자를 분리하여 pHZ22에 도입함으로써 pHZT224를 제조하였는데 이 plasmid vector도 Zymomonas로 conjugation에 의해 전이되어 안정하게 유지 되었다. 본 연구를 통하여 개발된 plasmid vector는 Z. mobilis와 E. coli에 공히 작용하는 shuttle vector 로서 외부 유전자를 Zymomonas에 도입시킬 수 있는 유용한 유전자 운반체임이 확인되었다.

• 대한수의학회지
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• 제19권1호
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• pp.75-83
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• 1979

The sensitivities of 270 pathogens (124 Streptococci, 118 Staphylococci, 10 Corynebacterium pyogenes and 18 Escherichia coli) isolated from clinical or subclinical cases of bovine mastitis during lactation to 11 antibiotics were determined by the agar plate dilution method. All cultures of Streptococci were inhibited at $1.56{\mu}g/ml$ of ampicillin and 1.56 units/ml of penicillin G. Most of the cultures were inhibited at $3.125{\mu}g/ml$ of leukomycin, but were resistant to kanamycin, streptomycin, chloramphenicol, erythromycin and colistin at concentration of $12.5{\mu}g/ml$. More than 93% of the Staphlococcal cultures were sensitive to kanamycin, leukomycin, ampicillin, tetracycline, ledermycin and minocycline at concentrations of $12.5{\mu}g/ml$ or less, and sensitive to penicillin at concentration of 3.125 units/ml, but for more than 71% of the cultures to chloramphenicol, erythromycin and colistin the concentrations required to inhibit growth were 100 ${\mu}g/ml$ or higher. All 10 cultures of Corynebacterium pyogenes were inhibited by leucomycin, ampicillin and minocycline at concentration of $1.56{\mu}g/ml$ and by penicillin G at concentration of 0.78 units/ml, but all the cultures required at least $400{\mu}g/ml$ or higher of streptomycin, erythromycin and colistin for inhibition. More than 83% of E. coli cultures were sensitive to erythromycin and minocycline at concentration of $12.5{\mu}g/ml$, but resistant to leucomycin and chloramphenicol at concentration of $100{\mu}g/ml$.

• Journal of Microbiology
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• 제43권3호
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• pp.251-256
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• 2005

In this study, we assessed the susceptibility of 12 Lactobacillus strains, all of which had been isolated from the gastrointestinal tracts of chicken, to three antibiotics (chloramphenicol, erythromycin and tetracycline) used commonly as selective markers in transformation studies of lactic acid bacteria. Among these strains, $17\%,\;58\%,\;and\;25\%$ were found to exhibit a high degree of resistance to $200\;{\mu}g/ml$ of tetracycline, erythromycin, and chloramphenicol, respectively. Seven of the 12 Lactobacillus strains exhibiting resistance to at least $50\;{\mu}g/ml$ of chloramphenicol or erythromycin, and five strains exhibiting resistance to at least $50\;{\mu}g/ml$ of tetracycline, were subsequently subjected to plasmid curing with chemical curing agents, such as novobiocin, acriflavin, SDS, and ethidium bromide. In no cases did the antibiotic resistance of these strains prove to be curable, with the exception of the erythromycin resistance exhibited by five Lactobacillus strains (L. acidophilus I16 and I26, L. fermentum I24 and C17, and L. brevis C10). Analysis of the plasmid profiles of these five cured derivatives revealed that all of the derivatives, except for L. acidophilus I16, possessed profiles similar to those of wild-type strains. The curing of L. acidophilus I16 was accompanied by the loss of 4.4 kb, 6.1 kb, and 11.5 kb plasmids.

• 대한미생물학회지
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• 제21권1호
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• pp.33-45
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• 1986

On hundred and forty stains of shigella cultures isolated from the twelve hygiene laboratories of cities and provincial general hospital laboratories in 1983 were tested for their resistance to thirteen antimicrobial drugs and their R-plasmid transfer. Antimicrobial drugs were used amikacin, ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, nalidixic acid, rifampicin, streptamycin, tetracycline, tobramycin, cefoperazone and piperacillin. All strains were resistant to one or more of thirteen antimicrobial drugs but 94.3% were susceptible to amikacin, gentamicin and tobramycin of total isolated. The most strains commonly found resistance was to chloramphenicol (94%) followed by streptamycin (93%), tetracyline (92%) piperacillin (90%) ampicillin (83%), cefoperazone (42%), nalidixic acid (14%), cephalothin (17%), rifampicin (22%) and kanamycin (6%), sixty percent of strains among 140 were resistance to ampicillin, chloramphenicol, streptomycin, tetracycline at the same time. The transfer of drug resistance by conjugation was tested and ninety four strains (94.3%) were resistant to one or more drugs were found to transfer their drug resistance of E. coli. percentage of transfer frequency by conjugation was one strains (54%), the transfer frequency of drug resistance varied by donor strains and recipients, but not by selecting drugs. Resistance to nalidixic acid was not transferred by conjugation to recipients. Percentage of plasmid curing after the treatment of acriflavine, acridine orange was about 8%. Among strains cured two strains were tested compare original strains with them in biochemical properties in arginine dihydrolase and arabinose fermentation reaction. It was found to growth curves of No.2 shigella flexneri, serotype 1b, and its derivatives cured with acriflavine in $M{\ddot{u}}ller$ Hinton broth medium (pH 7.4, $38^{\circ}C$) by temperature Gradient Biophoto Recorder TN-1120 (Tokyo, Japan).

• 미생물학회지
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• 제31권4호
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• pp.274-278
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• 1993

단백질이 어떻게 비수용성이 되는지를 알기위해, 클로람페니콜 아세틸전이효소와 베타-락타메이즈를 과잉생산하여 그들의 수용성과 활성을 측정하였다. 클로람페니콜 아세틸전이효소는 총단백질의 9에서 45%를 차지하였으며, inclusion body 형성없이 완전히 수용성이었으며, 효소활성은 만들어진 양과 비례하였다. 또한 30℃에서 T7 발현체계에 의해 생성된 베타-락타메이즈는 수용성의 숙성체였으나, 37℃에서는 비수용성이 되었다. 세포질에 있는 대부분의 베타-락타메이즈는 비수용성이었고. 페리플라즘 공간에서는 대부분이 수용성이었다. 단백질의 올바른 폴딩을 도와주는 chaperone의 일종인 GroEL 단백질은 본 실험조선에서는 베타-락타베이즈의 수용성을 별로 높이지는 못했다. 세포 내에서 inclusion body의 형성은 단백질의 높은 종도보다는 각각 단밸질 자체의 특성과 관련된 듯하다.

• 한국식품위생안전성학회지
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• 제8권4호
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• pp.215-223
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• 1993

클로람페니콜은 광벙위 항생물질로서 수의축산분야에서 널리 사용되어 왔으나 이 제제의 잠재적인 독성과 축산식풍 중 잔류성 때문에 세계 각국에서는 식용동물에서의 사용을 금지하고 있다. 따라서 이 시험에서는 미생물학척 방법에 의한 우유 및 식육 중 미량의 잔류클로람페니콜을 측정할 수 있는 방법을 확립하고자 M. luteus ATCC 9341을 시험용 균주로 설정하여 다음과 같은 결과를 얻었다. 1. 검출감도를 향상시키고자 시험명판용 Mueller-Hinton 배지의 배지량을 최소화하고 ethylacetate로 추출 농축하여 ml당 0.15/lg의 옥시테트라사이클린을 첨가한 회석용 인산염 완충액 (pH 6.0) 으로 잔류물을 용해하여 사용하였을 때 가기장 좋은 검출강도를 나타내였다. 2. 시료별 최저검출농도는 원유가 0.025 ppm이었으며, 식육은 0.05 ppm까지 검출할 수 있었다. 3. 시료별 평균 회수율은 원유가 68.5%이었으며, 쇠고기, 돼지고기 및 닭고기는 각각 65.1%. 63.8% 및 59.4%이었다. 이들 시료의 회수율에 대한 변이계수 (CV)는 1.8~15.1%이었다.

• 미생물학회지
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• 제5권2호
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• pp.97-101
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• 1967

Up to the present time, there are only three methods by which we can obtain bacteria free crown gall tissue. According to some papers related to this field, the first method is based on the works of Braun(53') who maintained infected plants at 46-47'c for several days. But the method has a problem that very few plants can tolerate this temperature. The second method is based on the well known observation that old tumors appear to be bacteria free at least 1 or 2% of the explants. Also this method is known to us as laborious and time consuming. The third method is the one we were using that was attempting to kill the bacteria with bacteriacidal agent such as Antibiotics. In fact., it is reported that almost complete control of crown gall of tomato was obtained by Blanchard('51) when plants were grown in a nutrient containing Aureomycin(20${\mu}g$/ml) following needle puncture with the gall bacteria. We have been engaged in making the experiment by applying solution of Penicillin, Streptomycin and of Chloramphenicol(Succinate free) to find the strong bacteriacidal agent through the method of disc plate, and to confirm the effect of antimicrobial action through the method of plant tissue culture system without possible injury to the host plant. The result of this report is the fact the strongest bacteriacidal agent among the above three Antibiotics was Chloramphenicol(Succinate free 1000 p.p.m). and that there happened no injury to the tissue cultures in a White's 10X media containing 1000 p.p.m. of Chloramphenicol.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1324-1329
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• 2012

Phosphomannomutase (ManB) is involved in the biosynthesis of GDP-mannose, which is vital for numerous processes such as synthesis of carbohydrates, production of alginates and ascorbic acid, and post-translational modification of proteins. Here, we discovered that a deletion mutant of manB (BG101) in Streptomyces coelicolor (S. coelicolor) showed higher sensitivity to bacteriostatic chloramphenicol (CM) than the wild-type strain (M145), along with decreased production of CM metabolites. Deletion of manB also decreased the mRNA expression level of drug efflux pumps (i.e., cmlR1 and cmlR2) in S. coelicolor, resulting in increased sensitivity to CM. This is the first report on changes in antibiotic sensitivity to CM by deletion of one glycolysis-related enzyme in S. coelicolor, and the results suggest different approaches for studying the antibiotic-resistant mechanism and its regulation.