1.Characterization of inulosucrase and the enzymatic synthesis of inulin.
Dawei NI ; Wei XU ; Ziwei CHEN ; Wenli ZHANG ; Wanmeng MU
Chinese Journal of Biotechnology 2021;37(1):266-275
As a type of prebiotics and dietary fiber, inulin performs plenty of significant physiological functions and is applied in food and pharmaceutical fields. Inulosucrase from microorganisms can use sucrose as the substrate to synthesize inulin possessing higher molecular weight than that from plants. In this work, a hypothetical gene coding inulosucrase was selected from the GenBank database. The catalytic domain was remained by N- and C- truncation strategies, constructing the recombinant plasmid. The recombinant plasmid was expressed in E. coli expression system, and after purifying the crude enzyme by Ni²⁺ affinity chromatography, a recombinant enzyme with a molecular weight of approximately 65 kDa was obtained. The optimal pH and temperature of the recombinant enzyme were 5.5 and 45 °C, respectively, when sucrose was used as the sole substrate. The activity of this enzyme was inhibited by various metal ions at different degrees. After purifying the produced polysaccharide, nuclear magnetic resonance analysis was used to determine that the polysaccharide was inulin connected by β-(2,1) linkages. Finally, the conditions for the production of inulin were optimized. The results showed that the inulin production reached the maximum, approximately 287 g/L after 7 h, when sucrose concentration and enzyme dosage were 700 g/L and 4 U/mL, respectively. The conversion rate from sucrose to inulin was approximately 41%.
Escherichia coli/genetics*
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Hexosyltransferases/genetics*
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Inulin
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Oligosaccharides
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Sucrose
2.The Significance of Clinical and Laboratory Features in the Diagnosis of Glycogen Storage Disease Type V: A Case Report.
Hyung Jun PARK ; Ha Young SHIN ; Yu Na CHO ; Seung Min KIM ; Young Chul CHOI
Journal of Korean Medical Science 2014;29(7):1021-1024
Glycogen storage disease type V (GSD-V) is the most common disorder of muscle glycogenosis with characteristic clinical and laboratory findings. A 32-yr-old woman complained of exercise intolerance and myoglobulinuria since early adolescence. She reported several episodes of second-wind phenomenon. Physical examination did not show any neurological abnormality, including fixed muscle weakness or atrophy. Serum creatine kinase level was 1,161 IU/L at rest. The result of the non-ischemic forearm exercise test was compatible with GSD-V. Mutation analysis identified the compound heterozygous mutations of the PYGM, p.D510fs and p.F710del, which has not yet been reported in Korea. The present case recognizes that detail clinical and laboratory analysis is the first step in the diagnosis of GSD-V.
Adult
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Base Sequence
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Creatine Kinase/blood
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Exons
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Female
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Frameshift Mutation
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Gene Deletion
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Genotype
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Glycogen Phosphorylase, Muscle Form/genetics
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Glycogen Storage Disease Type V/*diagnosis/genetics/pathology
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Humans
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Pedigree
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Sequence Analysis, DNA
3.Construction, expression and enzymatic activity analysis of AUR1 eukaryotic expression vector of Botrytis cinerea.
Yongchun QIU ; Xiaoping LIU ; Ping GOU
Chinese Journal of Biotechnology 2013;29(1):78-86
In order to study the expression and the activity of inositol phosphorylceramide synthase (BcAUR1 gene) in Botrytis cinerea, we amplified BcAUR1 by RT-PCR from Botrytis cinerea, using the special primers with FLAG and BamH I/Xho I restriction sites. Recombinant pYES2-BcAUR1 was constructed to transform into Saccharomyces cerevisae deltayorl by LiAC. The expression of inositol phosphorylceramide (IPC) synthase and its activity were detected by Western blotting and HPLC, respectively. The results show that pYES2-BcAUR1 could express in uracil mutant deltayorl of Saccharomyces cerevisae. IPC synthase enzyme activity of pYES2-BcAUR1 transformants significantly increased and was approximately double than no-load BcAUR1 transformants. The low concentration of Aureobasidin A could inhibit growth of no-load BcAUR1 transformants, but pYES2-BcAUR1 transformants could resist fungal growth inhibition which was induced by Aureobasidin A.
Botrytis
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enzymology
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genetics
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Depsipeptides
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pharmacology
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Fungal Proteins
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genetics
;
metabolism
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Gene Expression
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Genetic Vectors
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Hexosyltransferases
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genetics
;
metabolism
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Saccharomyces cerevisiae
;
genetics
;
metabolism
4.Short-Cut Pathway to Synthesize Cellulose of Encysting Acanthamoeba.
Eun Kyung MOON ; Hyun Hee KONG
The Korean Journal of Parasitology 2012;50(4):361-364
The mature cyst of Acanthamoeba is highly resistant to various antibiotics and therapeutic agents. Cyst wall of Acanthamoeba are composed of cellulose, acid-resistant proteins, lipids, and unidentified materials. Because cellulose is one of the primary components of the inner cyst wall, cellulose synthesis is essential to the process of cyst formation in Acanthamoeba. In this study, we hypothesized the key and short-step process in synthesis of cellulose from glycogen in encysting Acanthamoeba castellanii, and confirmed it by comparing the expression pattern of enzymes involving glycogenolysis and cellulose synthesis. The genes of 3 enzymes, glycogen phosphorylase, UDP-glucose pyrophosphorylase, and cellulose synthase, which are involved in the cellulose synthesis, were expressed high at the 1st and 2nd day of encystation. However, the phosphoglucomutase that facilitates the interconversion of glucose 1-phosphate and glucose 6-phosphate expressed low during encystation. This report identified the short-cut pathway of cellulose synthesis required for construction of the cyst wall during the encystation process in Acanthamoeba. This study provides important information to understand cyst wall formation in encysting Acanthamoeba.
Acanthamoeba castellanii/*enzymology/genetics/growth & development
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Amebiasis/*parasitology
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Cell Wall/*metabolism
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Cellulose/*biosynthesis/genetics
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Glucosyltransferases/genetics/metabolism
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Glycogen Phosphorylase/genetics/metabolism
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Protozoan Proteins/genetics/*metabolism
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UTP-Glucose-1-Phosphate Uridylyltransferase/genetics/metabolism
5.Regeneration of transgenic Lespedeza thunbergii expressing levansucrase gene (Sac B) from Bacillus subtilis.
Jin-You DU ; Xiao-Yang CHEN ; Gui-Rong ZHANG ; Wei LI ; Dong-Nan HU ; Zan-Min HU
Chinese Journal of Biotechnology 2006;22(6):940-944
The Bacillus subtilis Sac B gene with the vacuolar targeting signal sequence driven by 35S promotor was transferred into Lespedeza thunbergii by Agrobacterium mediated method. Total 62 Kan-resistant plants were obtained, of which 5 plants were proved to be transgenic plants. The transgenic plants were characterized by PCR amplification, PCR-Southern hybridization and RT-PCR. The physiological assay results showed that the transgenic plants were more tolerant to stress than the controls under the condition of 200mmol/L NaCl and 5% PEG, respectively, and that the content of soluble sugar in trnsgenic plants was significantly higher than that of controls in the period of tests (5-15 days) under salt and PEG stress.
Bacillus subtilis
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enzymology
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genetics
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Carbohydrate Metabolism
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Carbohydrates
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chemistry
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Hexosyltransferases
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genetics
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Lespedeza
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drug effects
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genetics
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growth & development
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metabolism
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Plants, Genetically Modified
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Reverse Transcriptase Polymerase Chain Reaction
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Sodium Chloride
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pharmacology
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Solubility
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Stress, Physiological
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drug effects
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Transformation, Genetic
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Transgenes
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genetics
6.Construction and optimization of Escherichia coli for producing rhamnolipid biosurfactant.
Zhijin GONG ; Yanfeng PENG ; Yuting ZHANG ; Guotian SONG ; Wujiu CHEN ; Shiru JIA ; Qinhong WANG
Chinese Journal of Biotechnology 2015;31(7):1050-1062
Rhamnolipid biosurfactant is mainly produced by Pseudomonas aeruginosa that is the opportunistic pathogenic strain and not suitable for future industrial development. In order to develop a relatively safe microbial strain for the production of rhamnolipid biosurfactant, we constructed engineered Escherichia coli strains for rhamnolipid production by expressing different copy numbers of rhamnosyltransferase (rhlAB) gene with the constitutive synthetic promoters of different strengths in E. coli ATCC 8739. We further studied the combinatorial regulation of rhlAB gene and rhaBDAC gene cluster for dTDP-1-rhamnose biosynthesis with different synthetic promoters, and obtained the best engineered strain-E. coli TIB-RAB226. Through the optimization of culture temperature, the titer of rhamnolipd reached 124.3 mg/L, 1.17 fold higher than that under the original condition. Fed-batch fermentation further improved the production of rhamnolipid and the titer reached the highest 209.2 mg/L within 12 h. High performance liquid chromatography-mass spectrometry (LC-MS) analysis showed that there are total 5 mono-rhamnolipid congeners with different nuclear mass ratio and relative abundance. This study laid foundation for heterologous biosynthesis of rhanomilipd.
Bacterial Proteins
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genetics
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Batch Cell Culture Techniques
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Decanoates
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Escherichia coli
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metabolism
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Fermentation
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Glycolipids
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biosynthesis
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Hexosyltransferases
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genetics
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Industrial Microbiology
;
methods
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Multigene Family
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Promoter Regions, Genetic
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Pseudomonas aeruginosa
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Rhamnose
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analogs & derivatives
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biosynthesis
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Surface-Active Agents
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metabolism
7.Molecular cloning and over-expression of a fructosyltransferase from Aspergillus niger QU10.
Guoqing ZHANG ; Jing YANG ; Jiaji SHI ; Shijun QIAN ; Yapeng CHAO
Chinese Journal of Biotechnology 2015;31(4):512-522
The main commercial production of fructooligosaccharides (FOS) comes from enzymatic transformation using sucrose as substrate by microbial enzyme fructosyltransferase. A fructosyltransferase genomic DNA was isolated from Aspergillus niger QU10 by PCR. The nucleotide sequence showed a 1 941 bp size, and has been submitted to GenBank (KF699529). The cDNA of the fructosyltransferase, containing an open reading frame of 1 887 bp, was further cloned by RT-PCR. The fructosyltransferase gene from Aspergillus niger was functionally expressed both in Escherichia coli and Pichia pastoris GS 115. The highest activity value for the construction with the α-factor signal peptide reached 431 U/mL after 3 days of incubation. The recombinant enzyme is extensively glycosylated, and the active form is probably represented by a homodimer with an apparent molecular mass of 200 kDa as judged from mobility in seminative PAGE gels. The extracellular recombinant enzyme converted sucrose mostly to FOS, mainly 1-kestose and nystose, liberating glucose. FOS reached a maximal value and represented about 58% of total sugars present in the reaction mixture after 4 h reaction. The results suggest that the availability of recombinant Pichia pastoris as a new source of a FOS-producing enzyme might result of biotechnology interest for industrial application.
Aspergillus niger
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enzymology
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genetics
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Base Sequence
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Cloning, Molecular
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DNA, Complementary
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Escherichia coli
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Fungal Proteins
;
genetics
;
metabolism
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Glycosylation
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Hexosyltransferases
;
genetics
;
metabolism
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Molecular Sequence Data
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Molecular Weight
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Pichia
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Sucrose
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metabolism
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Trisaccharides
;
metabolism
8.Effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury.
Zhi-gang CHEN ; Yi-cheng LU ; Cheng ZHU ; Guang-ji ZHANG ; Xue-hua DING ; Ji-yao JIANG
Chinese Journal of Traumatology 2003;6(1):23-27
<b>OBJECTIVEb>To observe the effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury (TBI).
<b>METHODSb>An acute experimental closed TBI model in rats was induced by a fluid-percussion brain injury model. At five and sixty minutes after TBI, the animals were intraperitoneally injected by ganglioside GM1 (30 mg/kg) or the same volume of saline. At the 6th hour after TBI, effects of ganglioside GM1 or saline on changes of mean arterial pressure (MAP), contents of water, lactic acid (LA) and lipid peroxidation (LPO) in the injured cerebral tissues were observed.
<b>RESULTSb>After TBI, MAP decreased and contents of water, LA and LPO increased in brain injury group; however, MAP was back to normal levels and contents of water, LA and LPO decreased in ganglioside GM1 treated group, compared with those in brain injury group (P < 0.05). No significant difference between the saline treated group and the brain injury group (P > 0.05) was observed.
<b>CONCLUSIONSb>Ganglioside GM1 does have obvious neuroprotective effect on early TBI.
Animals ; Brain ; metabolism ; Brain Edema ; etiology ; prevention & control ; Brain Injuries ; complications ; metabolism ; Disease Models, Animal ; Hexosyltransferases ; therapeutic use ; Lactic Acid ; analysis ; Lipid Peroxidation ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley
9.Characterization of the functional domain of STT3a of oligosaccharyltransferase from Dunaliella salina.
Cui WANG ; Jie LI ; Liping LIU ; Lei ZENG ; Lexun XUE
Chinese Journal of Biotechnology 2010;26(6):760-766
To investigate the function of STT3a gene in salt adaptation and flagellar regeneration of Dunaliella salina (D. salina), a pair of degenerate primers was designed according to conserved homologous amino acid sequences of VCVFTA and DVDYVL of STT3a from Chlamydomonas, Arabidopsis thaliana and other organisms. A cDNA sequence of 1 650 bp encoding a whole functional domain of STT3a was amplified from D. salina by RT-PCR and 3' Rapid Amplification of cDNA Ends (RACE), which shared homology with Chlamydomonas (48%), Arabidopsis thaliana (50%), Homo sapiens (46%), etc. Real-time fluorescence quantitative PCR (real-time Q-PCR) demonstrated that the STT3a mRNAs from D. salina were induced by increased concentration of NaCl, and increased to 11-fold higher by 3.5 mol/L NaCl than that by 1.5 mol/L NaCl (P < 0.01). Also, STT3a mRNA of D. salina maintained at a higher level in the process of flagellar regeneration with than without experiencing deflagellar treatment. In conclusion, the findings of this study demonstrate that the high expression of the STT3a gene enhances the capability of salt adaptation and flagellar regeneration in D. salina.
Adaptation, Physiological
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physiology
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Arabidopsis
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enzymology
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Chlamydomonas
;
enzymology
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Chlorophyta
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enzymology
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genetics
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Cloning, Molecular
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Flagella
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metabolism
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Hexosyltransferases
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chemistry
;
genetics
;
metabolism
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Membrane Proteins
;
chemistry
;
genetics
;
metabolism
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RNA, Messenger
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genetics
;
metabolism
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Saccharomyces cerevisiae Proteins
;
genetics
;
metabolism
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Sodium Chloride
;
pharmacology
10.Early Screening of Oxacillin-Resistant Staphylococcus aureus and Staphylococcus epidermidis from Blood Culture.
Joseph JEONG ; Chulhun Ludgerus CHANG ; Tae Sung PARK ; Seon Ho LEE ; Sung Ryul KIM ; Seok Hoon JEONG
Journal of Korean Medical Science 2002;17(2):168-172
The timely detection of blood-borne pathogens is one of the most important functions of the microbiology laboratory. Recently, methicillin-resistant staphylococci have become the most important pathogens seen by the laboratory. The purpose of this study was to evaluate Staphy agar, a novel screening medium, for the detection methicillin-resistant Staphylococcus aureus, S. epidermidis, or other coagulase-negative staphylococci (CNS) from positive blood cultures showing Gram-positive cocci in clusters. Eighty-six blood cultures that yielded Gram-positive cocci in clusters were included in this study. The organisms were finally identified by the Vitek system, and oxacillin resistance was confirmed by polymerase chain reaction (PCR)-based mecA gene detection. The identification and oxacillin resistance of all S. aureus strains showed complete agreement with the Vitek and PCR results. The presumptive detection of S. epidermidis and other CNS were consistent with the Vitek system in 94.7%, and the screening of oxacillin resistance was consistent with the result of PCR in 92.1% of 38 strains. The Staphy agar method is reliable and rapid for differentiating Gram-positive cocci in clusters in blood and for determining their methicillin resistance.
*Bacterial Proteins
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Carrier Proteins/genetics
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Drug Resistance, Microbial
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*Hexosyltransferases
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Muramoylpentapeptide Carboxypeptidase/genetics
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Oxacillin/*pharmacology
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Penicillin-Binding Proteins
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*Peptidyl Transferases
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Staphylococcus aureus/*drug effects/genetics
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Staphylococcus epidermidis/*drug effects/genetics