LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 5 of total 5

Search options

  1. Article ; Online: Using a Novel Lysin To Help Control Clostridium difficile Infections.

    Wang, Qiong / Euler, Chad W / Delaune, Aurelia / Fischetti, Vincent A

    Antimicrobial agents and chemotherapy

    2015  Volume 59, Issue 12, Page(s) 7447–7457

    Abstract: As a consequence of excessive antibiotic therapies in hospitalized patients, Clostridium difficile, a Gram-positive anaerobic spore-forming intestinal pathogen, is the leading cause of hospital-acquired diarrhea and colitis. Drug treatments for these ... ...

    Abstract As a consequence of excessive antibiotic therapies in hospitalized patients, Clostridium difficile, a Gram-positive anaerobic spore-forming intestinal pathogen, is the leading cause of hospital-acquired diarrhea and colitis. Drug treatments for these diseases are often complicated by antibiotic-resistant strains and a high frequency of treatment failures and relapse; therefore, novel nonantibiotic approaches may prove to be more effective. In this study, we recombinantly expressed a prophage lysin identified from a C. difficile strain, CD630, which we named PlyCD. PlyCD was found to have lytic activity against specific C. difficile strains. However, the recombinantly expressed catalytic domain of this protein, PlyCD1-174, displayed significantly greater lytic activity (>4-log kill) and a broader lytic spectrum against C. difficile strains while still retaining a high degree of specificity toward C. difficile versus commensal clostridia and other bacterial species. Our data also indicated that noneffective doses of vancomycin and PlyCD1-174 when combined in vitro could be significantly more bactericidal against C. difficile. In an ex vivo treatment model of mouse colon infection, we found that PlyCD1-174 functioned in the presence of intestinal contents, significantly decreasing colonizing C. difficile compared to controls. Together, these data suggest that PlyCD1-174 has potential as a novel therapeutic for clinical application against C. difficile infection, either alone or in combination with other preexisting treatments to improve their efficacy.
    MeSH term(s) Amidohydrolases/genetics ; Amidohydrolases/pharmacology ; Amino Acid Sequence ; Animals ; Anti-Bacterial Agents/pharmacology ; Anti-Bacterial Agents/therapeutic use ; Catalytic Domain ; Clostridium difficile/drug effects ; Clostridium difficile/genetics ; Colon/drug effects ; Colon/microbiology ; Drug Resistance, Multiple, Bacterial/genetics ; Endopeptidases/genetics ; Endopeptidases/pharmacology ; Enterocolitis, Pseudomembranous/drug therapy ; Female ; Hydrogen-Ion Concentration ; Mice, Inbred C57BL ; Molecular Sequence Data ; Prophages/genetics ; Recombinant Proteins/genetics ; Recombinant Proteins/pharmacology ; Recombinant Proteins/therapeutic use ; Vancomycin/pharmacology ; Viral Proteins/genetics ; Viral Proteins/pharmacology ; Viral Proteins/therapeutic use
    Chemical Substances Anti-Bacterial Agents ; Recombinant Proteins ; Viral Proteins ; Vancomycin (6Q205EH1VU) ; Endopeptidases (EC 3.4.-) ; endolysin (EC 3.4.99.-) ; Amidohydrolases (EC 3.5.-)
    Language English
    Publishing date 2015-12
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 217602-6
    ISSN 1098-6596 ; 0066-4804
    ISSN (online) 1098-6596
    ISSN 0066-4804
    DOI 10.1128/AAC.01357-15
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 809: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)
    Einzelsignatur: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: Peptidoglycan crosslinking relaxation plays an important role in Staphylococcus aureus WalKR-dependent cell viability.

    Delaune, Aurelia / Poupel, Olivier / Mallet, Adeline / Coic, Yves-Marie / Msadek, Tarek / Dubrac, Sarah

    PloS one

    2011  Volume 6, Issue 2, Page(s) e17054

    Abstract: The WalKR two-component system is essential for viability of Staphylococcus aureus, a major pathogen. We have shown that WalKR acts as the master controller of peptidoglycan metabolism, yet none of the identified regulon genes explain its requirement for ...

    Abstract The WalKR two-component system is essential for viability of Staphylococcus aureus, a major pathogen. We have shown that WalKR acts as the master controller of peptidoglycan metabolism, yet none of the identified regulon genes explain its requirement for cell viability. Transmission electron micrographs revealed cell wall thickening and aberrant division septa in the absence of WalKR, suggesting its requirement may be linked to its role in coordinating cell wall metabolism and cell division. We therefore tested whether uncoupling autolysin gene expression from WalKR-dependent regulation could compensate for its essential nature. Uncoupled expression of genes encoding lytic transglycosylases or amidases did not restore growth to a WalKR-depleted strain. We identified only two WalKR-regulon genes whose expression restored cell viability in the absence of WalKR: lytM and ssaA. Neither of these two genes are essential under our conditions and a ΔlytM ΔssaA mutant does not present any growth defect. LytM is a glycyl-glycyl endopeptidase, hydrolyzing the pentaglycine interpeptide crossbridge, and SsaA belongs to the CHAP amidase family, members of which such as LysK and LytA have been shown to have D-alanyl-glycyl endopeptidase activity, cleaving between the crossbridge and the stem peptide. Taken together, our results strongly suggest that peptidoglycan crosslinking relaxation through crossbridge hydrolysis plays a crucial role in the essential requirement of the WalKR system for cell viability.
    MeSH term(s) Bacterial Proteins/genetics ; Bacterial Proteins/metabolism ; Bacterial Proteins/physiology ; Carbohydrate Metabolism/genetics ; Carbohydrate Sequence/physiology ; Cell Wall/enzymology ; Cell Wall/metabolism ; Endopeptidases/metabolism ; Endopeptidases/physiology ; Gene Expression Regulation, Bacterial/physiology ; Gene Expression Regulation, Enzymologic/physiology ; Hydrolases/genetics ; Hydrolases/metabolism ; Hydrolysis ; Microbial Viability/genetics ; Models, Biological ; Multiprotein Complexes/metabolism ; Multiprotein Complexes/physiology ; Organisms, Genetically Modified ; Peptidoglycan/chemistry ; Peptidoglycan/metabolism ; Protein Multimerization/physiology ; Staphylococcus aureus/genetics ; Staphylococcus aureus/metabolism ; Staphylococcus aureus/physiology
    Chemical Substances Bacterial Proteins ; Multiprotein Complexes ; Peptidoglycan ; Hydrolases (EC 3.-) ; Endopeptidases (EC 3.4.-) ; LytM protein, Staphylococcus aureus (EC 3.4.99.-)
    Language English
    Publishing date 2011-02-28
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1932-6203
    ISSN (online) 1932-6203
    DOI 10.1371/journal.pone.0017054
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article ; Online: The WalKR system controls major staphylococcal virulence genes and is involved in triggering the host inflammatory response.

    Delauné, Aurélia / Dubrac, Sarah / Blanchet, Charlène / Poupel, Olivier / Mäder, Ulrike / Hiron, Aurélia / Leduc, Aurélie / Fitting, Catherine / Nicolas, Pierre / Cavaillon, Jean-Marc / Adib-Conquy, Minou / Msadek, Tarek

    Infection and immunity

    2012  Volume 80, Issue 10, Page(s) 3438–3453

    Abstract: The WalKR two-component system is essential for the viability of Staphylococcus aureus, playing a central role in controlling cell wall metabolism. We produced a constitutively active form of WalR in S. aureus through a phosphomimetic amino acid ... ...

    Abstract The WalKR two-component system is essential for the viability of Staphylococcus aureus, playing a central role in controlling cell wall metabolism. We produced a constitutively active form of WalR in S. aureus through a phosphomimetic amino acid replacement (WalR(c), D55E). The strain displayed significantly increased biofilm formation and alpha-hemolytic activity. Transcriptome analysis was used to determine the full extent of the WalKR regulon, revealing positive regulation of major virulence genes involved in host matrix interactions (efb, emp, fnbA, and fnbB), cytolysis (hlgACB, hla, and hlb), and innate immune defense evasion (scn, chp, and sbi), through activation of the SaeSR two-component system. The impact on pathogenesis of varying cell envelope dynamics was studied using a murine infection model, showing that strains producing constitutively active WalR(c) are strongly diminished in their virulence due to early triggering of the host inflammatory response associated with higher levels of released peptidoglycan fragments. Indeed, neutrophil recruitment and proinflammatory cytokine production were significantly increased when the constitutively active walR(c) allele was expressed, leading to enhanced bacterial clearance. Taken together, our results indicate that WalKR play an important role in virulence and eliciting the host inflammatory response by controlling autolytic activity.
    MeSH term(s) Animals ; Bacterial Proteins/genetics ; Bacterial Proteins/metabolism ; Biofilms ; Cytokines/metabolism ; DNA Footprinting ; Deoxyribonuclease I ; Escherichia coli K12/classification ; Escherichia coli K12/metabolism ; Flow Cytometry ; Gene Expression Regulation, Bacterial/physiology ; Humans ; Immunity, Innate ; Inflammation/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Microarray Analysis ; Staphylococcus aureus/genetics ; Staphylococcus aureus/metabolism ; Staphylococcus aureus/pathogenicity ; Staphylococcus aureus/physiology ; Virulence Factors/genetics ; Virulence Factors/metabolism
    Chemical Substances Bacterial Proteins ; Cytokines ; Virulence Factors ; Deoxyribonuclease I (EC 3.1.21.1)
    Language English
    Publishing date 2012-07-23
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 218698-6
    ISSN 1098-5522 ; 0019-9567
    ISSN (online) 1098-5522
    ISSN 0019-9567
    DOI 10.1128/IAI.00195-12
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 684: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article ; Online: Chromosomal integration of the extended-spectrum beta-lactamase gene blaCTX-M-15 in Salmonella enterica serotype Concord isolates from internationally adopted children.

    Fabre, Laëtitia / Delauné, Aurélia / Espié, Emmanuelle / Nygard, Karin / Pardos de la Gandara, Maria / Polomack, Lucette / Guesnier, Françoise / Galimand, Marc / Lassen, Jørgen / Weill, François-Xavier

    Antimicrobial agents and chemotherapy

    2009  Volume 53, Issue 5, Page(s) 1808–1816

    Abstract: We report the emergence of Salmonella enterica isolates of serotype Concord (and its monophasic variant 6,7:l,v:-) producing the extended-spectrum beta-lactamases (ESBLs) SHV-12 and CTX-M-15 in France and Norway between 2001 and 2006 (43 in France and 26 ...

    Abstract We report the emergence of Salmonella enterica isolates of serotype Concord (and its monophasic variant 6,7:l,v:-) producing the extended-spectrum beta-lactamases (ESBLs) SHV-12 and CTX-M-15 in France and Norway between 2001 and 2006 (43 in France and 26 in Norway). The majority of these isolates were from adopted children from Ethiopia, most of whom were healthy carriers. Several symptomatic secondary cases were found in the adoptive families and health care facilities in France. Serotype Concord isolates collected before 2003 produced SHV-12 encoded on a 340-kb conjugative plasmid of replicon IncI1. Isolates collected after 2003 produced CTX-M-15. We detected two conjugative plasmids carrying bla(CTX-M-15). One plasmid, approximately 300 kb in size, was positive for the IncHI2 replicon and the plasmid-mediated quinolone resistance gene qnrA1. The other plasmid, from one of the earliest CTX-M-15-producing isolates collected, was a fusion plasmid with IncY and IncA/C(2) replicons and was 200 kb in size. However, we showed, using Southern hybridization of I-CeuI-digested chromosomal DNA and S1 nuclease analysis of plasmid DNA, that most isolates had a bla(CTX-M-15) gene located on chromosomal DNA. Analysis of the flanking regions of the chromosomally located bla(CTX-M-15) gene by cloning revealed an ISEcp1 truncated by an intact IS26 upstream from the bla(CTX-M-15) gene and a truncated orf477 gene downstream from bla(CTX-M-15). We found regions beyond the IS26 and the orf477 genes that were derived from IncA/C(2) plasmids, suggesting the chromosomal integration of part of the bla(CTX-M-15)-carrying IncY and IncA/C(2) fusion plasmid from early CTX-M-15-producing isolates.
    MeSH term(s) Adoption ; Adult ; Aged, 80 and over ; Anti-Bacterial Agents/pharmacology ; Child, Preschool ; Chromosomes, Bacterial/genetics ; Conjugation, Genetic ; Drug Resistance, Bacterial/genetics ; Electrophoresis, Gel, Pulsed-Field ; France/epidemiology ; Humans ; Infant ; Internationality ; Microbial Sensitivity Tests ; Norway/epidemiology ; Plasmids ; Salmonella Infections/epidemiology ; Salmonella Infections/microbiology ; Salmonella enterica/classification ; Salmonella enterica/drug effects ; Salmonella enterica/enzymology ; Salmonella enterica/genetics ; Salmonella enterica/isolation & purification ; Serotyping ; beta-Lactamases/genetics
    Chemical Substances Anti-Bacterial Agents ; beta-lactamase CTX-M-15 (EC 3.5.2.-) ; beta-Lactamases (EC 3.5.2.6)
    Language English
    Publishing date 2009-03-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 217602-6
    ISSN 1098-6596 ; 0066-4804
    ISSN (online) 1098-6596
    ISSN 0066-4804
    DOI 10.1128/AAC.00451-08
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 809: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)
    Einzelsignatur: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article ; Online: Ceftriaxone-resistant salmonella enterica serotype Newport, France.

    Egorova, Svetlana / Timinouni, Mohammed / Demartin, Marie / Granier, Sophie A / Whichard, Jean M / Sangal, Vartul / Fabre, Laëtitia / Delauné, Aurélia / Pardos, Maria / Millemann, Yves / Espié, Emmanuelle / Achtman, Mark / Grimont, Patrick A D / Weill, François-Xavier

    Emerging infectious diseases

    2008  Volume 14, Issue 6, Page(s) 954–957

    Abstract: The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 beta-lactamase (Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during 2000-2005. Because this strain was not detected in ... ...

    Abstract The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 beta-lactamase (Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during 2000-2005. Because this strain was not detected in food animals, it was most likely introduced into France through imported food products.
    MeSH term(s) Animals ; Anti-Bacterial Agents/pharmacology ; Ceftriaxone/pharmacology ; Commerce ; Drug Resistance, Bacterial/genetics ; Electrophoresis, Gel, Pulsed-Field ; France/epidemiology ; Humans ; Meat/microbiology ; Salmonella Infections/epidemiology ; Salmonella Infections/microbiology ; Salmonella enterica/classification ; Salmonella enterica/drug effects ; Salmonella enterica/enzymology ; Salmonella enterica/genetics ; Sequence Analysis, DNA ; Serotyping ; beta-Lactamases/biosynthesis ; beta-Lactamases/genetics
    Chemical Substances Anti-Bacterial Agents ; Ceftriaxone (75J73V1629) ; beta-lactamase CMY-2 (EC 3.5.2.-) ; beta-Lactamases (EC 3.5.2.6)
    Language English
    Publishing date 2008-05-28
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1380686-5
    ISSN 1080-6059 ; 1080-6040
    ISSN (online) 1080-6059
    ISSN 1080-6040
    DOI 10.3201/eid1406.071168
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 4778: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top