• Microbiology and Biotechnology Letters
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• v.1 no.1
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• pp.19-23
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• 1973

This experiment was done to investigate the growth and the fine structural changes of Bacillus subtilis which were influenced by the penicillin with electromicroscope. The results were as follows; 1) The higher the concentration of penicillin the more prominent inhibition of the growth was observed. 2) The septa was not formed, derangements of synthesis of cell wall and cell membrane. 3) Cytoplasm was increased with swelling of cell body because of weakness of cell membrane induced by deranged synthesis of cell membrane. Some of the cells showed disruption of their membrane with loss of cytoplasm, remaining empty space, which suggest loss of cell function. 4) It can be suggested that penicillin had affected on the cell wall of Bacillus subtilis, and inhibited growth of the cell by deranging the formation of the cell wall.

• Journal of Microbiology and Biotechnology
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• v.7 no.3
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• pp.194-196
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• 1997

Using the polyclonal antibody for Xanthomonas citri ampicillin acylase raised in Pseudomonas-free Balb/c mice, the immunochemical similarity of several types of penicillin acylases including Erwinia aroideae penicillin V acylase, Escherichia coli penicillin G acylase, Pseudomonas melanogenum and Acetobacter turbidans ampicillin acylases, and Pseudomonas cephalosporin acylase was examined. Among tested, only P. melanogenum ampicillin acylase showed the cross-reactivity with the antibody.

• YAKHAK HOEJI
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• v.18 no.3
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• pp.209-216
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• 1974

From the measurements of infrared and fluorescence spectra riboflavin-2',3',4',5'-tetraacetate has been found to associate with penicillin-V more than strongly with themselves. They form the 1 : 1 cyclic hydrogen bonded dimer through the imino and the 2-C carbonyl groups of the isoalloxazine ring and the imino group of the penicillin-V ressidue. Pernicillin-V is an effective quencher of the fluorescence of riboflavin through hydrogen bonds partly due to the collision interaction with the penicillin ring.

• International Journal of Oral Biology
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• v.40 no.1
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• pp.35-39
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• 2015

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of bacteria. It has been reported that sub-MIC of antibiotics may result in morphological alterations, along with the biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of Aggregatibacter actinomycetemcomitans, after the treatment with sub-MIC metronidazole and penicillin. The bacterial morphology was observed with scanning electron microscope, after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans was increased after the incubation with sub-MIC metronidazole and penicillin. Sub-MIC metronidazole and penicillin inhibited bacterial division and induced long filaments. Our study showed that metronidazole and penicillin can induce the morphological changes in A. actinomycetemcomitans.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2990-2994
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• 2014

The studies on design and synthesis of new monocyclic ${\beta}$-lactam esters 4(R/S)-(1'-methoxycarbonylpropyl- 2'(R/S)-thio)-3(R)-phenylacetamidoazetidin-2-one (3a) and 4(R/S)-(1'-methoxycarbonyl-2'-methylpropyl-2'- thio)-3(R)-phenylacetamidoazetidin-2-one (3b) were described. Compounds 3a and 3b were specifically designed to retain all penicillin substructures except the bicyclic system, which would be conceived by cleaving the C(3)-N(4) bond of penicillin G. Compounds 3a and 3b are of particular interest in the context of the structural elucidation of monocyclic ${\beta}$-lactams originated from penicillin. Key intermediates, ${\beta}$-mercapto esters 6a and 6b, were synthesized from conjugate acids 4a and 4b using three-step synthetic sequences, respectively, and 4(S)-acetoxy-3(S)-phenylacetamidoazetidin-2-one (7) was obtained from the degradation of penicillin G. Reactions of 6a and 6b with 7, thus obtained, provided the target compounds 3a and 3b, respectively.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.314-319
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• 2008

Penicillin G amidase (PGA, benzylpenicillinaminohydrolase, EC 3.5.1.11) is industrially important enzyme which converts penicillin G to 6-aminopenicillanic acid (6-APA) and phenylacetic acid (PAA). The PGA in E. coli ATCC 11105 is secreted into the periplasm after removing signal sequences and becomes heterodimer which composed of two subunits, small subunit (24 kDa) and large subunit (65 kDa). In this study, the PGA gene was obtained from E. coli ATCC 11105 using PCR (polymerase chain reaction) technique. The active PGA was successfully secreated into periplasm in E. coli BL2 1(DE3) harboring pET-pga plasmid. The optimized fed-batch fermentation, consisting of a three-step shift of culture temperature from $37^{\circ}C$ to $22^{\circ}C$, gave a productivity of 19.6 U/mL with a cell growth of 62 O.D. at 600 nm.

• Pediatric Infection and Vaccine
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• v.5 no.2
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• pp.215-220
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• 1998

Purpose : Asymptomatic infections with positive throat culture for group A beta-hemolytic streptococci(GABHS) and high antistreptolysin O(ASO) concentration may lead to sequelae such as rheumatic fever or acute poststreptococcal glomerulonephritis. Children with asymptomatic infections were treated with oral penicillin V to evaluate the effectiveness of penicillin treatment on the asymptomatic infections. Methods : Throat culture and ASO concentration analysis were performed against healthy elementary school children. Thirty-six children with positive throat culture for GABHS and ASO concentrations of 400 IU/mL or more were divided into two groups. Twenty-two children were treated with oral penicillin V for 10 days, and the others were not treated. Eradication rate of GABHS and the change of ASO concentration between the two groups were compared after one month later. Results : Eradication rates of GABHS between treated and untreated children were 91%(20/22) and 50%(7/14) respectively(P<0.05). Children showing elevation of ASO levels more than 100IU/mL were 22%(4/18) in the treated group and 30%(3/10) in the untreated group, while children showing a decrease of more than 200IU/mL in the ASO level were 44%(8/18) and 40%(4/10) respectively. Conclusion : We confirmed the validity of penicillin treatment, because when we treated the asymptomatic children with penicillin V, the GABHS was eradicated effectively. But there was no significant difference of decrease in the ASO levels between the two groups due to long half-life of ASO or poor compliance. Treatment failure was 22% in terms of elevated ASO levels after penicillin treatment.

• The Journal of the Korean dental association
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• v.52 no.7
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• pp.425-431
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• 2014

Objectives : The purpose of our study was to evaluate penicillin as a still drug of choice for severe endodontic infection, by analyzing the antimicrobial susceptibilities from endodontic infections with swelling to figure out appropriate antibiotics as empirical treatment. Materials and methods : This study involved 18 patients who attended for emergency treatment because of facial or periapical swelling associated with root canal infections. Identification and antimicrobial susceptibility test of each pathogen were performed by Vitek2 Systems (bioM$\acute{e}$rieux, Marcy l'Etoile, France). Results : The most frequent bacteria was Streptococcus spp.(77%), and the resistance against penicillin was 35% in overall patients, followed by clindamycin and erythromycin (17%), which was much higher than previous studies. Conclusions : In our study, the higher resistance made penicillin alone not to be chosen as the first antibiotic drug for severe endodontic infections. Combinations with other drug, penicillin with wider spectrum of activity, or changing to other antibiotics was considered while remembering the increased risk of resistant microorganism.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.62-67
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• 2004

The biosynthesis of cephalexin was carried out in the aqueous two-phase systems using penicillin acylase as a catalyst, and 7-aminodeacetoxicephalosporanic acid (7-ADCA) and phenylglycine methyl ester (PGME) as substrates. 20% PEG400-l7.5% ${(NH_4)}_2SO_4$ containing 0.5 M NaCl and 1.5 M methanol aqueous two-phase systems (ATPS) were selected as reaction medium, and 53% product yield was obtained using immobilized penicillin acylase as a catalyst. 20% PEG400-l5% $MgSO_4$ ATPS was also used for the synthesis of cephalexin, and 60-62% product yield was obtained by using free penicillin acylase as a catalyst. When batch reactions were repeated in the ATPS, the cephalexin yields decreased during the reactions due to deactivation, loss, and product inhibition of penicillin acylase. The effect of different ratio of phenylglycine methyl ester to 7-ADCA on the product yield was investigated, and high cephalexin yield was obtained at a high molar ratio.

• Korean Journal of Veterinary Research
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• v.13 no.1
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• pp.57-62
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• 1973

The antibiotics are usually used for the medical treatments or the other purpose for cow and almost of them are transfered to milk. Moreover a serious problems on public health are caused by misuse or overuse of antibiotics. These studies were conducted to determine the rise and fall of antibiotics in the raw milk which is milked from the cow treated with antibiotics. The number of samples examined were 500 which were taken from 36 cows, and the antibiotics in milk were detected by cylinder plate assay method. The results were as follows: 1) When penicillin, chloramphenycol and streptomycin were infused into a udder, they were detected up to the period of 84 hours, 36 hours and 60 hours after injection in the milk from the same udder, however in the milk from the other udder streptomycin was not detected but penicillin and chloramphenycol were detected up to 72 hours and 24 hours after injection. When streptomycin and penicillin were injected intramusculary, streptomycin was not detected in the milk but penicillin was detected up to 60 hours after injcetion. 2) When penicillin, streptomycin and chloramphenycol were infused into the udder, the lesser amount of milk was produced, the more antibiotics were detected in the milk. 3) It is necessary policy for the public health to inhibit to be sold the milk up to 3 days or more after the injection on antibiotics or to add food blue to mastitis drugs.