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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 19.
Clostridium difficile Toxin A Inhibits Erythropoietin Receptor-Mediated Colonocyte Focal Adhesion Through Inactivation of Janus Kinase-2.
Abstract Previously, we demonstrated that the erythropoietin receptor (EpoR) is present on fibroblasts, where it regulates focal contact. Here, we assessed whether this action of EpoR is involved in the reduced cell adhesion observed in colonocytes exposed to Clostridium difficile toxin A. EpoR was present and functionally active in cells of the human colonic epithelial cell line HT29 and epithelial cells of human colon tissues. Toxin A significantly decreased activating phosphorylations of EpoR and its downstream signaling molecules JAK-2 (Janus kinase 2) and STAT5 (signal transducer and activator of transcription...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Nam ST, Seok H, Kim DH, Nam HJ, Kang JK, Eom JH, Lee MB, Kim SK, Park MJ, Chang JS, Ha EM, Shong KE, Hwang JS, Kim H Tags: J Microbiol Biotechnol Source Type: research
Alkaliphilic endoxylanase from lignocellulolytic microbial consortium metagenome for biobleaching of eucalyptus pulp.
In this study, an alkaliphilic endoxylanase gene was isolated from metagenomic DNA of a structurally stable thermophilic lignocellulose-degrading microbial consortium using amplification with conserved glycosyl hydrolase family 10 primers and subsequent genome walking. The full-length xylanase showed 78% sequence identity to an endo-beta-1,4-xylanase of Clostridium phytofermentans and was expressed in a mature form with an N-terminal His6 tag fusion in Escherichia coli. The recombinant xylanase Xyn3F was thermotolerant and alkaliphilic, working optimally at 65-70 degrees C with an optimal pH at 9- 10 and retaining >80% ...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Weerachavangkul C, Laothanachareon T, Boonyapakron K, Wongwilaiwalin S, Nimchua T, Eurwilaichitr L, Pootanakit K, Igarashi Y, Champreda V Tags: J Microbiol Biotechnol Source Type: research
A Human Fungal Pathogen Cryptococcus neoformans Expresses Three Distinct Iron Permease Homologs.
Abstract Iron plays a key role in host-pathogen interactions. Microbial pathogens require iron for survival and virulence, whereas mammalian hosts sequester and withhold iron as a means of nutritional immunity. We previously identified two paralogous genes, CFT1 and CFT2, which encode homologs of a fungal iron permease, Cft1 and Cft2, respectively, in the human fungal pathogen Cryptococcus neoformans. Cft1 was shown to play a role in the highaffinity reductive iron uptake system, and was required for transferrin utilization and full virulence in mammalian hosts. However, no role of Cft2 has been suggested yet. Here...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Han K, Do E, Jung WH Tags: J Microbiol Biotechnol Source Type: research
Porphyrin Derivatives from a Recombinant Escherichia coli Grown on Chemically Defined Medium.
Abstract We have reported previously that a recombinant Escherichia coli co-expresses aminolevulinic acid (ALA) synthase, an NADP-dependent malic enzyme, and a dicarboxylate transporter-produced heme, an iron-chelated porphyrin, in a succinate-containing complex medium. To develop an industrially plausible process, a chemically defined medium was formulated based on M9 minimal medium. Heme synthesis was enhanced by adding sodium bicarbonate, which strengthened the C4 metabolism required for the precursor metabolite, although a pH change discouraged cell growth. Increasing the medium pH buffering capacity (100mM pho...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Lee MJ, Chun SJ, Kim HJ, Kwon AS, Jun SY, Kang SH, Kim P Tags: J Microbiol Biotechnol Source Type: research
Effect of TSHAC on Human Cytochrome P450 Activity, and Transport Mediated by P-Glycoprotein.
Abstract TSAHC [4'-(p-toluenesulfonylamido)-4-hydroxychalcone] is a promising antitumorigenic chalcone compound, especially against TM4SF5 (four-transmembrane L6 family member 5)-mediated hepatocarcinoma. We evaluated the potential of TSAHC to inhibit the catalytic activities of nine cytochrome P450 isoforms and of P-glycoprotein (Pgp). The abilities of TSAHC to inhibit phenacetin Odeethylation (CYP1A2), coumarin 6-hydroxylation (CYP2A6), bupropion hydroxylation (CYP2B6), amodiaquine Ndeethylation (CYP2C8), diclofenac 4-hydroxylation (CYP2C9), omeprazole 5-hydroxylation (CYP2C19), dextromethorphan O-demethylation (...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Im Y, Kim YW, Song IS, Joo J, Shin JH, Wu Z, Lee HS, Park KH, Liu KH Tags: J Microbiol Biotechnol Source Type: research
Identification of 5-Hydroxy-3,6,7,8,3´,4´-Hexamethoxyflavone from Hizikia fusiforme Involved in the Induction of the Apoptosis Mediators in Human AGS Carcinoma Cells.
Abstract An 80% ethanol extract of Hizikia fusiforme was obtained and followed by successive fractionation using the organic solvents n-hexane, ethyl acetate, and n-butanol to identify the antioxidative substance. The aqueous part of the nbutanol fractionation step, showing high antioxidative activity, was subjected to reverse-phase liquid chromatography. As a result, a substance purified from a BB-2 fraction showed high antioxidative activity. The m/z 419 [M+H] molecular ion peak in the fraction was observed by the analysis of the ESI-LC/MS spectrum. By the analysis of 1H NMR (500 MHz, DMSO-d6) and 13C NMR (125 MH...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Kim MJ, Lee HH, Seo MJ, Kang BW, Park JU, Kim KS, Kim GY, Joo WH, Choi YH, Cho YS, Jeong YK Tags: J Microbiol Biotechnol Source Type: research
Preparation of corncob grits as a carrier for immobilizing yeast cells for ethanol production.
In this study, DEAE-corncobs [delignified corncob grits derivatized with 2-(diethylamino)ethyl chloride hydrochloride (DEAE·HCl)] were prepared as a carrier to immobilize yeast (Saccharomyces cerevisiae) for ethanol production. The immobilized yeast cell reactor produced ethanol under optimized DEAE·HCl derivatization and adsorption conditions between yeast cells and the DEAE-corncobs. When delignified corncob grit (3.0 g) was derivatized with 0.5M DEAE·HCl, the yeast cell suspension (OD600 = 3.0) was adsorbed at >90% of the initial cell OD600. This amount of adsorbed yeast cells was estimated to be 5.36 mg-dry cells...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Lee SE, Lee CG, Kang do H, Lee HY, Jung KH Tags: J Microbiol Biotechnol Source Type: research
Effect of dilute alkali on structural features and enzymatic hydrolysis of barley straw (Hordeum vulgare) at boiling temperature with low residence time.
Abstract This work was conducted to evaluate the effect of dilute sodium hydroxide (NaOH) on barley straw at boiling temperature and fractionation of its biomass components into lignin, hemicellulose, and reducing sugars. To this end, various concentrations of NaOH (0.5% to 2%) were applied for pretreatment of barley straw at 105 degrees C for 10 min. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform infrared (FTIR) spectroscopy studies revealed that 2% NaOHpretreated barley straw exposed cellulose fibers on which surface granules were abolished due to comprehensive removal of...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Haque MA, Nath Barman D, Kang TH, Kim MK, Kim J, Kim H, Yun HD Tags: J Microbiol Biotechnol Source Type: research
Cloning, Expression, and Characterization of a Glycoside Hydrolase Family 118 beta-Agarase from Agarivorans sp. JA-1.
We report a glycoside hydrolase (GH)-118 beta-agarase from a strain of Agarivorans, in which we previously reported recombinant expression and characterization of the GH- 50 beta-agarase. The GH comprised an open reading frame of 1,437 base pairs, which encoded a protein of 52,580 daltons consisting of 478 amino acid residues. Assessment of the entire sequence showed that the enzyme had 97% nucleotide and 99% amino acid sequence similarities to those of GH-118 beta-agarase from Pseudoalteromonas sp. CY24, which belongs to a different order within the same class. The gene corresponding to a mature protein of 440 amino acids...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Lee DG, Jeon MJ, Lee SH Tags: J Microbiol Biotechnol Source Type: research
Bioconversion of Piceid to Piceid Glucoside Using Amylosucrase from Alteromonas macleodii Deep Ecotype.
Abstract Resveratrol, or its glycoside form piceid, is a dietary antioxidant polyphenolic compound, found in grapes and red wine that has been shown to have protective effects against cardiovascular disease. However, very low water solubility of the compound may limit its application in the food and pharmaceutical industries. The amylosucrase (AMAS) of Alteromonas macleodii Deep ecotype was expressed in Escherichia coli and showed high glycosyltransferase activity to produce the glucosyl piceid when piceid was used as an acceptor. The conversion yield of piceid glucoside was 35.2%. Biotransformation using culture o...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Park H, Kim J, Park JH, Baek NI, Park CS, Lee HS, Cha J Tags: J Microbiol Biotechnol Source Type: research
Purification and Characterization of Beta-Glucosidase from Weissella cibaria 37.
Abstract A gene encoding beta-glucosidase was cloned from Weissella cibaria 37, an isolate from human feces. Sequence analysis showed that the gene could encode a protein of 415 amino acids in length, and the translated amino acid sequence showed homology (34-31%) with glycosyl hydrolase family 1 beta-glucosidases. The gene was overexpressed in E. coli BL21(DE3) using pET26b(+) and a 50 kDa protein was overproduced, which matched well with the calculated size of the enzyme, 49,950.87 Da. Recombinant beta-glucosidase was purified by using a his-tag affinity column. The purified beta-glucosidase had an optimum pH and...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Lee KW, Han NS, Kim JH Tags: J Microbiol Biotechnol Source Type: research
Identification of the beta-Glucosidase Gene from Bifidobacterium animalis subsp. lactis and Its Expression in B. bifidum BGN4.
Abstract beta-Glucosidase is necessary for the bioconversion of glycosidic phytochemicals in food. Two Bifidobacterium strains (Bifidobacterium animalis subsp. lactis SH5 and B. animalis subsp. lactis RD68) with relatively high beta- glucosidase activities were selected among 46 lactic acid bacteria. A beta-glucosidase gene (bbg572) from B. lactis was shotgun cloned, fully sequenced, and analyzed for its transcription start site, structural gene, and deduced transcriptional terminator. The structural gene of bbg572 was 1,383 bp. Based on amino sequence similarities, bbg572 was assigned to family 1 of the glycosyl h...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Youn SY, Park MS, Ji GE Tags: J Microbiol Biotechnol Source Type: research
Structural Analysis of alpha-L-Arabinofuranosidase from Thermotoga maritima Reveals Characteristics for Thermostability and Substrate Specificity.
Abstract An alpha-L-arabinofuranosidase (TmAFase) from Thermotoga maritima MSB8 is a highly thermostable exo-acting hemicellulase that exhibits a relatively higher activity towards arabinan and arabinoxylan, compared with other glycoside hydrolase 51 family enzymes. In the present study, we carried out the enzymatic characterization and structural analysis of TmAFase. Tight domain associations found in TmAFase, such as an inter-domain disulfide bond (Cys306 and Cys476) in each monomer, a novel extended arm (amino acids 374-385) at the dimer interface, and total 12 salt bridges in the hexamer, may account for the th...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Dumbrepatil A, Park JM, Jung TY, Song HN, Jang MU, Han NS, Kim TJ, Woo EJ Tags: J Microbiol Biotechnol Source Type: research
Factors affecting adhesion of lactic Acid bacteria to caco-2 cells and inhibitory effect on infection of salmonella typhimurium.
In this study, seven strains isolated from mustard leaf kimchi were screened for their tolerance to simulated gastric and bile juices, the adhesive properties to Caco-2 cells, and the inhibition ability of Salmonella Typhimurium ATCC 29631 adhesion. Lactobacillus acidophilus GK20, Lactobacillus paracasei GK74, and Lactobacillus plantarum GK81, which were resistant to bile as well as gastric juices, possessed high bile-salt hydrolase (BSH) activity towards both sodium glycocholate and sodium taurocholate. The strongest in vitro adherence of 53.96 +/- 4.49% was exhibited by L. plantarum GK81 followed by L. acidophilus GK20 w...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Lim SM, Ahn DH Tags: J Microbiol Biotechnol Source Type: research
Isolation and identification of fungi from a meju contaminated with aflatoxins.
Abstract A home-made meju sample contaminated naturally with aflatoxins was used for isolation of fungal strains. Overall, 230 fungal isolates were obtained on dichloran rosebengal chloramphenicol (DRBC) and dichloran 18% glycerol (DG18) agar plates. Morphological characteristics and molecular analysis of a partial beta-tubulin gene and the internal transcribed spacer (ITS) of rDNA were used for the identification of the isolates. The fungal isolates were divided into 7 genera: Aspergillus, Eurotium, Penicillium, Eupenicillium, Mucor, Lichtheimia, and Curvularia. Three strains from 56 isolates of the A. oryzae/flav...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Jung YJ, Chung SH, Lee HK, Chun HS, Hong SB Tags: J Microbiol Biotechnol Source Type: research
Feasibility of Brewing Makgeolli Using Pichia anomala Y197-13, a Non-Saccharomyces cerevisiae.
This study investigated the fermentation and sensory characteristics of using wild yeast strains for brewing makgeolli. A non-Saccharomyces cerevisiae strain was isolated from nuruk and termed Y197-13. It showed 98% similarity to Pichia anomala and had an optimal growth temperature of 25 degrees C. Makgeolli was manufactured using koji, jinju nuruk, and improved nuruk as fermentation agents. Y197-13 makgeolli brewed with koji had alcohol and solids contents of 11.1% and 13.9%, respectively. Sweet sensory characteristics were attributed to residual sugars in makgeolli with 6% alcohol. The makgeolli had a fresh sour taste an...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Kim H, Kim JH, Bai DH, Ahn B Tags: J Microbiol Biotechnol Source Type: research
Kinetic Studies of Alkaline Protease from Bacillus licheniformis NCIM-2042.
Abstract An extensive investigation was carried out to describe the kinetics of cell growth, substrate consumption, and product formation in the batch fermentation using starch as substrate. Evaluation of intrinsic kinetic parameters was carried out using a best-fit unstructured model. A nonlinear regression technique was applied for computational purpose. The Andrew's model showed a comparatively better R2 value among all tested models. The values of specific growth rate (micronmax), saturation constant (KS), inhibition constant (KI), and YX/S were found to be 0.109 h-1, 11.1 g/l, 0.012 g/l, and 1.003, respectivel...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Bhunia B, Basak B, Bhattacharya P, Dey A Tags: J Microbiol Biotechnol Source Type: research
Enhancing the Hexavalent Chromium Bioremediation Potential of Acinetobacter junii VITSUKMW2 Using Statistical Design Experiments.
Abstract The Cr(VI) removal capability of Acinetobacter junii VITSUKMW2 isolated from the Sukinda chromite mine site was evaluated and enhanced using statistical design techniques. The removal capacity was evaluated at different pH values (5-11) and temperatures (30-40 degrees C) and with various carbon and nitrogen sources. Plackett- Burman design was used to select the operational parameters for bioremediation of Cr(VI). Three parameters (molasses, yeast extract, and Cr(VI) concentration) were chosen for further optimization using central composite design. The optimal combination of parameters was found to be 14....
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Pulimi M, Jamwal S, Samuel J, Chandrasekaran N, Mukherjee A Tags: J Microbiol Biotechnol Source Type: research
Development of an indirect ELISA and immunocapture rt-PCR for lily virus detection.
Abstract Multiple viruses such as Lily symptomless virus (LSV), Lily mottle virus (LMoV), and cucumber mosaic virus (CMV) are the most prevalent viruses infecting lilies in Korea. Leaf samples and bulbs showing characteristic symptoms of virus infection were collected from Gangwon, Chungnam, and Jeju provinces of Korea in 2008-2011. Coat protein (CP) genes of LSV and LMoV were amplified from collected samples by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into a pET21d(+) expression vector to generate recombinant CPs. The resulting carboxy-terminal His-tagged CPs were expressed in Escherichi...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Kim JH, Yoo HN, Bae EH, Jung YT Tags: J Microbiol Biotechnol Source Type: research
Bio-Derived Poly(gamma-Glutamic Acid) Nanogels as Controlled Anticancer Drug Delivery Carriers.
Abstract We have developed a novel type of polymer nanogel loaded with anticancer drug based on bio-derived poly(gamma- glutamic acid) (gamma-PGA). gamma-PGA is a highly anionic polymer that is synthesized naturally by microbial species, most prominently in various bacilli, and has been shown to have excellent biocompatibility. Thiolated gamma-PGA was synthesized by covalent coupling between the carboxyl groups of gamma-PGA and the primary amine group of cysteamine. Doxorubicin (Dox)-loaded gamma-PGA nanogels were fabricated using the following steps: (1) an ionic nanocomplex was formed between thiolated gamma-PGA ...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Bae HH, Cho MY, Hong JH, Poo H, Sung MH, Lim YT Tags: J Microbiol Biotechnol Source Type: research
Up-Regulation of p27Kip1 Protects hES Cells from Differentiation-Associated and Caspase 3-Dependent Apoptosis.
Abstract Recently, it has been suggested that p27Kip1, the cell cycle regulatory protein, plays a pivotal role in the progression of normal differentiation in murine embryonic stem (mES) cells. In the current study, we investigated the role of p27Kip1 in the regulation of differentiation and apoptotic induction using Western blotting, quantitative real-time RT-PCR, and small interfering RNA (siRNA) assays and confocal laser scanning microscopic analysis of H9 human ES (hES) cells and H9-derived embryoid bodies (EBs) grown for 10 (EB10) and 20 days (EB20). Our results demonstrate that the proteins p27Kip1 and cyclin...
Source: Journal of Microbiology and Biotechnology - December 1, 2012 Category: Biotechnology Authors: Park SH, Kim MK, Lee CH Tags: J Microbiol Biotechnol Source Type: research
Arginine Methylation Regulates Antibody Responses through Modulating Cell Division and Isotype Switching in B Cells
Abstract Protein arginine methylation plays a crucial role including signal transduction, transcriptional control, cell proliferation and/or differentiation. B cells undergo clonal division, isotype switching, and antibody forming cells following stimulation with toll‐like receptor‐ligand (TLR‐L) lipopolysaccharide (LPS) and T cell‐derived signals including CD40‐L and IL‐4. It was examined whether protein arginine methylation affects B cell division and/or isotype switching to IgG1 in response to LPS, IL‐4, and CD40‐L using arginine methyltransferase inhibitor AdOx. The addition of AdOx substantially preven...
Source: Microbiology and Immunology - December 1, 2012 Category: Microbiology Authors: Kikumi Hata, Junichiro Mizuguchi Tags: Original Article Source Type: research
Diagnostic Value of Serum High Mobility Group Box Protein 1 and Soluble CD163 Levels in Brucellosis
Abstract Both CD4+ and CD8+ T lymphocytes play key roles in immunity to Brucella, in part because they secrete interferon (IFN)‐γ and activate the bactericidal functions in macrophages. Therefore, use of markers, which can evaluate macrophage activation, may have diagnostic and prognostic significance. High mobility group‐box 1 protein (HMGB1) is a late‐onset pro‐inflammatory cytokine secreted from activated macrophages. Soluble hemoglobin scavenger receptor (sCD163) is a specific marker of anti‐inflammatory macrophages. The aim of this study was to investigate associations of HMGB1 and sCD163 levels with Brucel...
Source: Microbiology and Immunology - December 1, 2012 Category: Microbiology Authors: Ayşe Oğuz Ayarcı, Emel Yılmaz, Deniz Sığırlı, Ferah Budak, Güher Göral, Haluk Barbaros Oral Tags: Original Article Source Type: research
Electron Transport at the Microbe-Mineral Interface: a synthesis of current research challenges.
Abstract Many bacterial and archaeal species can couple growth to the respiratory reduction or oxidation of insoluble mineral oxides of transition metals. These solid substrates are abundant electron sinks and sources for life on Earth, but, since they are insoluble in water, they cannot enter the bacterial cells. So, to exploit these electron sinks and sources, specific respiratory electron-transfer mechanisms must overcome the physical limitations associated with electron transfer between a microbe and extracellular metal oxides. Recent microbiological, geochemical, biochemical, spectroscopic and structural work ...
Source: Biochemical Society Transactions - December 1, 2012 Category: Biochemistry Authors: Richardson DJ, Fredrickson JK, Zachara JM Tags: Biochem Soc Trans Source Type: research
Biogeochemistry and microbiology of microaerobic Fe(II) oxidation.
Abstract Today high Fe(II) environments are relegated to oxic-anoxic habitats with opposing gradients of O2 and Fe(II); however, during the late Archaean and early Proterozoic eons, atmospheric O2 concentrations were much lower and aqueous Fe(II) concentrations were significantly higher. In current Fe(II)-rich environments, such as hydrothermal vents, mudflats, freshwater wetlands or the rhizosphere, rusty mat-like deposits are common. The presence of abundant biogenic microtubular or filamentous iron oxyhydroxides readily reveals the role of FeOB (iron-oxidizing bacteria) in iron mat formation. Cultivation and cul...
Source: Biochemical Society Transactions - December 1, 2012 Category: Biochemistry Authors: Emerson D Tags: Biochem Soc Trans Source Type: research
Operational and technical considerations for microbial electrosynthesis.
Abstract Extracellular electron transfer has, in one decade, emerged from an environmental phenomenon to an industrial process driver. On the one hand, electron transfer towards anodes leads to production of power or chemicals such as hydrogen, caustic soda and hydrogen peroxide. On the other hand, electron transfer from cathodes enables bioremediation and bioproduction. Although the microbiology of extracellular electron transfer is increasingly being understood, bringing the processes to application requires a number of considerations that are both operational and technical. In the present paper, we investigate t...
Source: Biochemical Society Transactions - December 1, 2012 Category: Biochemistry Authors: Desloover J, Arends JB, Hennebel T, Rabaey K Tags: Biochem Soc Trans Source Type: research
Resistance is futile: the bacteriocin model for addressing the antibiotic resistance challenge.
Abstract Pathogenic bacteria resistant to many or all antibiotics already exist. With the decline in microbiological research at pharmaceutical companies, the high rate at which resistance has evolved and spread has demanded a novel approach to addressing this critical human health issue. In the present paper, we propose a new paradigm in antibiotic discovery and development, one that applies ecological and evolutionary theory to design antimicrobial drugs that are more difficult and/or more costly to resist. In essence, we propose to simply adopt the strategies invented and applied by bacteria for hundreds of mill...
Source: Biochemical Society Transactions - December 1, 2012 Category: Biochemistry Authors: Riley MA, Robinson SM, Roy CM, Dennis M, Liu V, Dorit RL Tags: Biochem Soc Trans Source Type: research
Methods for studying the in vitro susceptibility of Candida spp. to antifungals.
Abstract In recent years, an increase of systemic Candida infections was noted. Thus, identification and susceptibility testing to antifungals became of considerable importance. The technique of dilution in liquid medium developed by « National committee for clinical laboratory standards » NCCLS or more recently named CLSI « Clinical and laboratory standards institute » is the reference method most used. The European committee "European committee on antibiotic susceptibility testing" or EUCAST has made progress by determining the susceptibility of strains within a shorter time. However, the use of these tec...
Source: Annales de Biologie Clinique - December 1, 2012 Category: Biochemistry Authors: Abbes S, Trabelsi H, Amouri I, Sallemi H, Nej S, Fatma C, Makni F, Ayadi A Tags: Ann Biol Clin (Paris) Source Type: research
Isobutanol production from D‐xylose by recombinant Saccharomyces cerevisiae
Abstract Simultaneous overexpression of an optimized, cytosolically localized valine biosynthesis pathway together with overexpression of xylose isomerase XylA from Clostridium phytofermentans, transaldose Tal1 and xylulokinase Xks1 enabled recombinant Saccharomyces cerevisiae cells to complement the valine auxotrophy of ilv2,3,5 triple deletion mutants for growth on D‐xylose as the sole carbon source. Moreover, after additional overexpression of ketoacid decarboxylase Aro10 and alcohol dehydrogenase Adh2 the cells were able to ferment xylose directly to isobutanol. © 2012 Federation of European Microbiological Societie...
Source: FEMS Yeast Research - December 1, 2012 Category: Research Authors: Dawid Brat, Eckhard Boles Tags: Short Communication Source Type: research
Microbial Biofilms and Gastrointestinal Diseases
Abstract The majority of bacteria live not planktonically, but as residents of sessile biofilm communities. Such populations have been defined as ‘matrix‐enclosed microbial accretions, which adhere to both biological and non‐biological surfaces’. Bacterial formation of biofilm is implicated in many chronic disease states. Growth in this mode promotes survival by increasing community recalcitrance to clearance by host immune effectors and therapeutic antimicrobials. The human GI tract encompasses a plethora of nutritional and physicochemical environments, many of which are ideal for biofilm formation and survival. H...
Source: FEMS Immunology and Medical Microbiology - December 1, 2012 Category: Microbiology Authors: Erik C. Rosenvinge, Graeme A. O'May, Sandra Macfarlane, George T. Macfarlane, Mark E. Shirtliff Tags: MiniReview Source Type: research
Differential interactions of Streptococcus gordonii and Staphylococcus aureus with cultured osteoblasts
Summary The impedance of normal osteoblast function by microorganisms is at least in part responsible for failure of dental or orthopedic implants. Staphylococcus aureus is a major pathogen of bone, and exhibits high levels of adhesion and invasion of osteoblasts. In this article we show that the commensal oral bacterium Streptococcus gordonii also adheres to and is internalized by osteoblasts. Entry of S. gordonii cells had typical features of phagocytosis, similar to S. aureus, with membrane protrusions characterizing initial uptake, and closure of the osteoblast membrane leading to engulfment. The sensitivities of S. go...
Source: Oral Microbiology and Immunology - December 1, 2012 Category: Microbiology Authors: Catherine E. Jauregui, Jason P. Mansell, Mark A. Jepson, Howard F. Jenkinson Tags: Original Article Source Type: research
Analysis of tryptophan‐rich region in Clostridium septicum alpha‐toxin involved with binding to GPI‐anchored proteins
We examined the contribution of individual amino acids in the tryptophan‐rich region to the cytotoxicity and binding to GPI‐anchored proteins using mutant toxins. For the retention of maximal cytotoxic activity, W307 and W311 were essential residues and residue 309 had to be hydrophobic and possess an aromatic side chain, such as tryptophan or phenylalanine. When residue 308 lying between tryptophans (W307 and W309) was changed from an acidic to a basic amino acid, cytotoxic activity of the mutant was reduced compared with that of the wild type. It was shown in a toxin overlay assay that the cytotoxic activity of each ...
Source: Microbiology and Immunology - December 1, 2012 Category: Microbiology Authors: Masafumi Mukamoto, Ryota Kimura, Mudenda B. Hang'ombe, Tomoko Kohda, Shunji Kozaki Tags: Original Article Source Type: research
Updated model of group A Streptococcus M proteins based on a comprehensive worldwide study
ConclusionsBased on these global data, the M6 protein model is updated to a three representative M protein (M5, M80, M77) model, to aid in epidemiological analysis, vaccine development and M protein‐related pathogenesis studies.© 2012 The Authors Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases
Source: Clinical Microbiology and Infection - December 1, 2012 Category: Microbiology Authors: David J. McMillan, Pierre‐Alexandre Drèze, Therese Vu, Debra E. Bessen, Julien Guglielmini, Andrew C. Steer, Jonathan R. Carapetis, Laurence Melderen, Kadaba S. Sriprakash, Pierre R. Smeesters, Tags: Original Article Source Type: research
Unravelling genomic diversity of the Zygosaccharomyces rouxii complex with a link to its life cycle
Abstract Zygosaccharomyces rouxii and the related species Zygosaccharomyces sapae (hereafter referred to as the Z. rouxii complex) are protoploid hemiascomycete yeasts relevant in the elaboration and spoilage of foodstuff. Divergence of the Z. rouxii complex before whole genome duplication (WGD), leading to the genus Saccharomyces, makes these yeasts very attractive for genome evolution study. Relatively little is known, however, about the diversity in this branch at the genetic and physiological levels. In this work, we investigated the Z. rouxii complex, encompassing strains that in other works have been studied separate...
Source: FEMS Yeast Research - December 1, 2012 Category: Research Authors: Lisa Solieri, Tikam Chand Dakal, Maria Antonietta Croce, Paolo Giudici Tags: Research Paper Source Type: research
Subclinical VZV reactivation in immunocompetent children hospitalized in ICU associated with prolonged fever duration
In conclusion, VZV reactivation occurs in immunocompetent children under severe stress and is associated with prolonged fever duration. © 2012 The Authors Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases
Source: Clinical Microbiology and Infection - December 1, 2012 Category: Microbiology Authors: Vassiliki Papaevangelou, Mark Quinlivan, Julianne Lockwood, Orestis Papaloukas, Georgia Sideri, Elena Critselis, Ioannis Papasotiriou, John Papadatos, Judy Breuer Tags: Original Article Source Type: research
A novel comprehensive analysis method for Staphylococcus aureus pathogenicity islands
ABSTRACT Staphylococcus aureuspathogenicity islands (SaPIs) form a growing family of mobile genetic elements in Staphylococci. Horizontal genetic transfer by mobile genetic elements plays an important role in the evolution of S. aureus. Several SaPIs carry staphylococcal enterotoxin (SE) and SE‐like toxin (SEl) genes. To comprehensively investigate the diversity of SaPIs, we designed a series of primers corresponding to sequences flanking six SaPI insertion sites in S. aureus genome and established Long and Accurate (LA)‐PCR analysis method. LA‐PCR products of 13‐17 Kbp were observed in the strains harboring seb,se...
Source: Microbiology and Immunology - December 1, 2012 Category: Microbiology Authors: Yusuke Sato'o, Katsuhiko Omoe, Hisaya K. Ono, Akio Nakane, Dong‐Liang Hu Tags: Original Article Source Type: research
Characteristics of Porphyromonas gingivalis LPS on its co‐cultivating with Fusobacterium nucleatum
Summary Porphyromonas gingivalis is associated with chronic periodontitis, and forms biofilm with multi‐species. Also, they can communicate within species as well as organisms of other species found in subgingiva, which may induce changes of growth ratio and virulence of periodontopathogens. P. gingivalis lipopolysaccharide shows different virulence by growth condition. The purpose of this study was to investigate characteristics of P. gingivalis LPS in its co‐cultivation with Fusobacterium nucleatum. After cultivation of P. gingivalis in the presence and absence of F. nucleatum, P. gingivalis LPS was extracted. THP‐...
Source: Oral Microbiology and Immunology - December 1, 2012 Category: Microbiology Authors: Sung‐Hoon Lee, Dong‐Heon Baek Tags: Original Article Source Type: research
High rates of transmitted drug resistance among newly‐diagnosed antiretroviral naïve HIV patients in Northern Greece, data from 2009‐2011
Europe‐wide surveillance data estimated the prevalence of transmission of drug‐resistant HIV‐1 in Europe to be stabilizing at levels as high as 8.4% (95% CI: 7.4% ‐9.5%) for the period 2002‐2006 . Consistently, studies reporting on more recent nationwide data provided comparable estimates for transmitted drug resistance (TDR) across Europe ranging from 5.6% to 12.4% [2‐6]. Previously published surveillance data from Northern Greece estimated the prevalence of TDR in newly diagnosed antiretroviral naïve patients to be 12.5% during the period 2000 ‐2007, while time trends suggested an increase in rates of T...
Source: Clinical Microbiology and Infection - December 1, 2012 Category: Microbiology Authors: Lemonia Skoura, Simeon Metallidis, Dimitrios Pilalas, Andreas Kourelis, Apostolia Margariti, Evangelia Papadimitriou, Zoe Anna Antoniadou, Theofilos Chrysanthidis, Olga Tsachouridou, Panagiotis Kollaras, Pavlos Nikolaidis, Nikolaos Malisiovas Tags: Research Note ‐ online only Source Type: research
Transcriptional repression by glycerol of genes involved in the assimilation of n‐alkanes and fatty acids in yeast Yarrowia lipolytica
Abstract The yeast Yarrowia lipolytica assimilates n‐alkanes or fatty acids as carbon sources. Transcriptional activation by n‐alkanes of ALK1 encoding a cytochrome P450 responsible for the terminal hydroxylation has been well studied so far, but its regulation by other carbon sources is poorly understood. Here we analyzed the transcriptional regulation of ALK1 by glycerol. Glycerol is a preferable carbon source compared to glucose for Y. lipolytica. The n‐decane‐induced transcript levels of ALK1 as well as the reporter gene under the control of ALK1 promoter were significantly decreased in the simultaneous presenc...
Source: FEMS Yeast Research - December 1, 2012 Category: Research Authors: Katsuki Mori, Ryo Iwama, Satoshi Kobayashi, Hiroyuki Horiuchi, Ryouichi Fukuda, Akinori Ohta Tags: Research Paper Source Type: research
The Toxoplasma nuclear factor TgAP2XI‐4 controls bradyzoite gene expression and cyst formation
Abstract Toxoplasma gondii undergoes many phenotypic changes during its life cycle. The recent identification of AP2 transcription factors in T. gondii has provided a platform for studying the mechanisms controlling gene expression. In the present study, we report that a recombinant protein encompassing the TgAP2XI‐4 AP2 domain was able to specifically bind to a DNA motif using gel retardation assays. TgAP2XI‐4 protein is localised in the parasite nucleus throughout the tachyzoite life‐cycle in vitro, with peak expression occurring after cytokinesis. We found that the TgAP2XI‐4 transcript level was higher in bradyz...
Source: Molecular Microbiology - December 1, 2012 Category: Microbiology Authors: Robert Walker, Mathieu Gissot, Matthew M. Croken, Ludovic Huot, David Hot, Kami Kim, Stanislas Tomavo Tags: Research Article Source Type: research
VimA mediates multiple functions that control virulence in Porphyromonas gingivalis
Abstract Porphyromonas gingivalis, a black‐pigmented, Gram‐negative anaerobe, is an important etiologic agent of periodontal disease. Its ability to survive in the periodontal pocket and orchestrate the microbial/host activities that can lead to disease suggest that P. gingivalis possesses a complex regulatory network involving transcriptional and post‐transcriptional mechanisms. The vimA (virulence modulating) gene is part of the 6.15‐kb bcp‐recA‐vimA‐vimE‐vimF‐aroG locus and plays a role in oxidative stress resistance. In addition to the glycosylation and anchorage of several surface proteins including ...
Source: Oral Microbiology and Immunology - December 1, 2012 Category: Microbiology Authors: A. Wilson Aruni, A. Robles, Hansel M. Fletcher Tags: Review article Source Type: research
P. gingivalis‐Nucleoside‐diphosphate‐kinase Inhibits ATP‐Induced Reactive‐Oxygen‐Species via P2X7 Receptor / NADPH‐Oxidase Signaling and Contributes to Persistence
Summary Ligation of P2X7 receptors with a “danger signal”, extracellular ATP (eATP), has recently been shown to result in production of intracellular reactive‐oxygen‐species (ROS) in macrophages. We show that primary gingival epithelial cells (GECs) produce sustained, robust cellular ROS upon stimulation by eATP. The induction of ROS was mediated by P2X7 receptor signaling coupled with NADPH‐oxidase activation, as determined by pharmacological inhibition and RNA‐interference. Furthermore, Porphyromonas gingivalis, an oral opportunistic pathogen, up‐regulated the antioxidant glutathione response, modulated eAT...
Source: Cellular Microbiology - December 1, 2012 Category: Microbiology Authors: Chul Hee Choi, Ralee Spooner, Jefferson DeGuzman, Theofilos Koutouzis, David M. Ojcius, Özlem Yilmaz Tags: Research Article Source Type: research
Knowledge versus consensus: the endocarditis prophylaxis paradigm
Abstract Antibiotic prophylaxis against endocarditis used to be implemented according to outdated ideas, based on the limited knowledge available in ancient times. Identification of streptococci of oral origin in cases of endocarditis was associated with the demonstration that patients often had poor dental condition. When receiving dental care, they develop bacteraemia. These facts convinced of the need to implement antibiotic prophylaxis during dental care; and this became the basis of an international consensus, thus based on deduction instead of evidence. © 2012 The Authors Clinical Microbiology and Infection © 2012 ...
Source: Clinical Microbiology and Infection - December 1, 2012 Category: Microbiology Authors: Dominique Grisoli, Didier Raoult Tags: Infection Hot Topic Source Type: research
Innate immune recognition of flagellin limits systemic persistence of Brucella
Abstract Brucella are facultative intracellular bacteria that cause chronic infections by limiting innate immune recognition. It is currently unknown whether Brucella FliC flagellin, the monomeric subunit of flagellar filament, is sensed by the host during infection. Here, we used two mutants of Brucella melitensis, either lacking or overexpressing flagellin to show that FliC hinders bacterial replication in vivo. The use of cells and mice genetically deficient for different components of inflammasomes suggested that FliC was a target of the cytosolic innate immune receptor NLRC4 in vivo but not in macrophages in vitro whe...
Source: Cellular Microbiology - December 1, 2012 Category: Microbiology Authors: Matthieu Terwagne, Jonathan Ferooz, Hortensia G. Rolán, Yao‐Hui Sun, Vidya Atluri, Mariana N. Xavier, Luigi Franchi, Gabriel Núñez, Thomas Legrand, Richard A. Flavell, Xavier De Bolle, Jean‐Jacques Letesson, Renée M. Tsolis Tags: Research Article Source Type: research
Genetic differentiation in Pyrenophora teres f. teres populations from Syria and Tunisia as assessed by AFLP markers
ConclusionsAFLP profiling is an effective method for typing the genetically diverse pathogen Pyrenophora teres f. teres. Significance and Impact of the studyThe study represents a comparative analysis of the genetic diversity in P. teres isolates from two countries spanning two continents and also shows that several distinct P. teres genotypes may be found in a given environment.The implications of these findings for Pyrenophora teres f. teres evolutionary potential and net blotch‐resistance breeding in Syria and Tunisia were also discussed.© 2012 The Authors Letters in Applied Microbiology © 2012 The Society for Applied Microbiology
Source: Letters in Applied Microbiology - December 1, 2012 Category: Microbiology Authors: Aida Bouajila, Néjia Zoghlami, Samer Murad, Michael Baum, Abdelwahed Ghorbel, Kumarse Nazari Tags: Original Article Source Type: research
Presence of indicator bacteria, diarrheagenic E. coli pathotypes and Salmonella in fresh carrot juice from Mexican restaurants
Coliform bacteria (CB), fecal coliforms (FC), Escherichia coli, diarrheagenic E. coli pathotypes (DEP) and Salmonella frequencies were determined for fresh carrot juice from restaurants in Pachuca city, Mexico. Two hundred and eighty carrot juice samples were purchased in three types of restaurants: (A), national chain restaurants; (B), local restaurants; and (C), very small restaurants. Two restaurants for each A and B, and three for C, were included. Forty juice samples were purchased at each restaurant. © 2012 The Authors Letters in Applied Microbiology © 2012 The Society for Applied Microbiology
Source: Letters in Applied Microbiology - December 1, 2012 Category: Microbiology Authors: M. del Refugio Torres‐Vitela, Carlos A. Gómez Aldapa, Jorge F. Cerna‐Cortes, Angélica Villarruel‐López, Esmeralda Rangel‐Vargas, Javier Castro‐Rosas Tags: Original Article Source Type: research
Comparative proteomic analysis of rice seedlings in response to inoculation with Bacillus cereus
Abstract Reports suggest that Bacillus spp. can be used to increase plant growth and resistance to disease, but the molecular mechanisms underlying the interaction between Bacillus spp. and plant is not completely understood. In the present study, to clarify these underlying mechanisms, the interaction between Bacillus cereus and rice was investigated using two‐dimensional gel electrophoresis. Through comparative analysis, a total of 31 differentially expressed proteins were obtained upon Bacillus cereus NMSL88 treatment, including 22 proteins that were up‐regulated and nine that were down‐regulated. These data indic...
Source: Letters in Applied Microbiology - December 1, 2012 Category: Microbiology Authors: Weiduo Wang, Li‐na Chen, Huijun Wu, Haoyu Zang, Shengfeng Gao, Yang Yang, Shanshan Xie, Xuewen Gao Tags: Original Article Source Type: research
Endocytic SNAREs are involved in optimal Coxiella burnetii vacuole development.
Summary Coxiella burnetii is a Gram‐negative intracellular bacterium. As previously described, both the endocytic and the autophagic pathways contribute to the maturation of Coxiella replicative vacuoles (CRVs). The large CRVs share the properties of both phagolysosomal and autophagolysosomal compartments. Vamp3, Vamp7 and Vamp8 are v‐SNAREs involved in the endocytic pathway which participate mainly in the fusion between endosomes and lysosomes. In the present study we observed that Vamp7 interacts with C. burnetii at different infection times (1h‐48h p.i.). We have determined that a truncated mutant of Vamp7 (Vamp7 ...
Source: Cellular Microbiology - December 1, 2012 Category: Microbiology Authors: Emanuel Martín Campoy, María Eugenia Mansilla, María Isabel Colombo Tags: Research Article Source Type: research
Responses of community structure of amoA‐encoding archaea and ammonia‐oxidizing bacteria in ammonia biofilter with rockwool mixtures to the gradual increases of ammonium and nitrate
ConclusionsThe specific FA in circulation water seems to be the important factor which relates to the AOB and AEA community shifts in the biofilter besides ammonium and pH.© 2012The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology
Source: Journal of Applied Microbiology - December 1, 2012 Category: Microbiology Authors: T. Yasuda, M. Waki, K. Kuroda, D. Hanajima, Y. Fukumoto, T. Yamagishi, Y. Suwa, K. Suzuki Tags: Original Article Source Type: research
Evaluation of Biocidal efficacy of copper alloy coatings in comparison with solid metal surfaces: generation of organic copper phosphate nanoflowers
ConclusionsOur data indicate that increasing the surface roughness of copper alloys had a pronounced impact on the membrane integrity of gram‐positive and, to a lesser degree, gram‐negative bacteria. In the presence of phosphate‐buffered saline, carbon‐copper‐phosphate‐containing nanoflowers were formed, likely nucleated by components derived from killed bacteria. The intimate association of the bacteria with the nanoflowers and phosphor bronze coating likely contributed to their non‐reversible adhesion.© 2012The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology
Source: Journal of Applied Microbiology - December 1, 2012 Category: Microbiology Authors: Heldder Gutierrez, Thomas Portman, Valerian Pershin, Maurice Ringuette Tags: Original Article Source Type: research