Base de dados : MEDLINE
Pesquisa : G06.099.115 [Categoria DeCS]
Referências encontradas : 3297 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 330 ir para página                         

  1 / 3297 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28452704
[Au] Autor:Yan CH; Hahn S; McMahon D; Bonislawski D; Kennedy DW; Adappa ND; Palmer JN; Jiang P; Lee RJ; Cohen NA
[Ad] Endereço:Department of Otorhinolaryngology-Head and Neck Surgery, Division of Rhinology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
[Ti] Título:Nitric oxide production is stimulated by bitter taste receptors ubiquitously expressed in the sinonasal cavity.
[So] Source:Am J Rhinol Allergy;31(2):85-92, 2017 Mar 01.
[Is] ISSN:1945-8932
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Bitter taste receptors (T2R) have recently been demonstrated to contribute to sinonasal innate immunity. One T2R, T2R38, regulates mucosal defense against gram-negative organisms through nitric oxide (NO) production, which enhances mucociliary clearance and directly kills bacteria. To determine whether additional T2Rs contribute to this innate defense, we evaluated two other sinonasal T2Rs (T2R4 and T2R16) for regulation of NO production and expression within the human sinonasal cavity. METHODS: Primary human sinonasal cultures were stimulated with ligands specific to T2R4 and T2R16, colchicine and D-salicin, respectively. Cellular NO production was measured by intracellular 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate fluorescence. For T2R expression mapping, sinonasal tissue was obtained from patients who underwent sinus surgery of the middle turbinate, maxillary sinus, ethmoid sinus, or sphenoid sinus. The expression of T2R4, T2R16, and T2R38 was evaluated by using immunofluorescence with validated antibodies. RESULTS: Similar to T2R38, T2R4 and T2R16 trigger NO production in a dose-dependent manner by using the canonical taste signaling pathway in response to stimulation with their respective ligands. All three receptors were expressed in the cilia of human epithelial cells of all regions in the sinonasal cavity. CONCLUSION: These three T2Rs signaled through the same NO-mediated antimicrobial pathway and were ubiquitously expressed in the sinonasal epithelium. Additional T2Rs besides T2R38 may play a role in sinonasal immune defense. Mapping of T2R expression demonstrated the potential widespread role of T2Rs in sinonasal defense, whereas the genetics of these T2Rs may contribute to our understanding of specific endotypes of chronic rhinosinusitis and develop into novel therapeutic targets.
[Mh] Termos MeSH primário: Infecções Bacterianas/imunologia
Mucosa Nasal/imunologia
Seios Paranasais/metabolismo
Receptores Acoplados a Proteínas-G/metabolismo
Rinite/imunologia
Sinusite/imunologia
Paladar
[Mh] Termos MeSH secundário: Bacteriólise
Células Cultivadas
Doença Crônica
Seres Humanos
Imunidade Inata
Depuração Mucociliar
Mucosa Nasal/microbiologia
Óxido Nítrico/metabolismo
Cultura Primária de Células
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Receptors, G-Protein-Coupled); 0 (taste receptors, type 2); 31C4KY9ESH (Nitric Oxide)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.2500/ajra.2017.31.4424


  2 / 3297 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28929273
[Au] Autor:Su J; Sun H; Liu J; Guo Z; Fan G; Gu G; Wang G
[Ad] Endereço:Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.
[Ti] Título:Complete genome sequence of a novel lytic bacteriophage isolated from Ralstonia solanacearum.
[So] Source:Arch Virol;162(12):3919-3923, 2017 Dec.
[Is] ISSN:1432-8798
[Cp] País de publicação:Austria
[La] Idioma:eng
[Ab] Resumo:A lytic podophage RSPI1 was isolated from tobacco field soil collected in Fujian Province, South China using host bacterium Ralstonia solanacearum Tb15-14. Whole genome sequencing of this phage was performed using the high-throughput Ion Torrent PGM Sequencer. The complete genome of RSPI1 was 43,211 bp in length with a mean DNA G + C content of 61.5%. A total of 48 open reading frames were identified with lengths ranging from 132 bp to 5,061 bp, of which, 11, 12 and 25 were identified as functional, structural and unknown genes, respectively. A BLAST analysis revealed that this phage genome had a query cover of 78-79% and a highest identity of 84% with four podophages that infect Burkholderia pseudomallei. Two neighbor-joining phylogenetic trees were constructed using phage DNA polymerase I and tail fiber protein sequences and showed that this phage is closely related to Burkholderia phage Bp-AMP1, and also related to several phages that infect Ralstonia solanacearum. These findings indicate that RSPI1 is a novel phage that infects the notorious plant pathogen Ralstonia solanacearum.
[Mh] Termos MeSH primário: Bacteriófagos/classificação
Bacteriófagos/isolamento & purificação
Podoviridae/classificação
Podoviridae/isolamento & purificação
Ralstonia solanacearum/virologia
[Mh] Termos MeSH secundário: Bacteriólise
Bacteriófagos/genética
Bacteriófagos/fisiologia
Composição de Bases
Burkholderia pseudomallei/virologia
China
Genoma Viral
Sequenciamento de Nucleotídeos em Larga Escala
Fases de Leitura Aberta
Filogenia
Podoviridae/genética
Podoviridae/fisiologia
Análise de Sequência de DNA
Homologia de Sequência
Microbiologia do Solo
Tabaco/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171113
[Lr] Data última revisão:
171113
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170921
[St] Status:MEDLINE
[do] DOI:10.1007/s00705-017-3555-2


  3 / 3297 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28886124
[Au] Autor:Geng P; Tian S; Yuan Z; Hu X
[Ad] Endereço:Key Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.
[Ti] Título:Identification and genomic comparison of temperate bacteriophages derived from emetic Bacillus cereus.
[So] Source:PLoS One;12(9):e0184572, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cereulide-producing Bacillus cereus isolates can cause serious emetic (vomiting) syndrome and even acute lethality. As mobile genetic elements, the exploration of prophages derived from emetic B. cereus isolates will help in our understanding of the genetic diversity and evolution of these pathogens. In this study, five temperate phages derived from cereulide-producing B. cereus strains were induced, with four of them undergoing genomic sequencing. Sequencing revealed that they all belong to the Siphoviridae family, but presented in different forms in their hosts. PfNC7401 and PfIS075 have typical icosahedral heads, probably existing alone as phagemids in the host with self-replicating capability in the lysogenic state. PfEFR-4, PfEFR-5, and PfATCC7953 have elongated heads, with the genomes of the former two identified as linear dsDNA, which could be integrated into the host genome during the lysogenic state. Genomic comparison of the four phages with others also derived from emetic B. cereus isolates showed similar genome structures and core genes, thus displaying host spectrum specificity. In addition, phylogenic analysis based on the complete genome and conserved tail fiber proteins of 36 Bacillus species-derived phages confirmed that the phages derived from emetic B. cereus strains were highly similar. Furthermore, one endolysin LysPfEFR-4 was cloned and showed lytic activity against all tested emetic B. cereus strains and cross-lytic activity against some other pathogenic bacteria, implying a potential to control bacterial contamination in the food supply.
[Mh] Termos MeSH primário: Fagos Bacilares/genética
Bacillus cereus/virologia
Genoma Viral
Genômica
[Mh] Termos MeSH secundário: Fagos Bacilares/classificação
Fagos Bacilares/metabolismo
Fagos Bacilares/ultraestrutura
Bacteriólise
Análise por Conglomerados
Biologia Computacional/métodos
Ordem dos Genes
Genômica/métodos
Sequenciamento de Nucleotídeos em Larga Escala
Especificidade de Hospedeiro
Filogenia
Proteômica/métodos
Ensaio de Placa Viral
Vômito/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171018
[Lr] Data última revisão:
171018
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170909
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0184572


  4 / 3297 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28765589
[Au] Autor:Hubbard AT; Coates AR; Harvey RD
[Ad] Endereço:Infection and Immunity Research Centre, Division of Clinical Sciences, St George's, University of London, London, UK.
[Ti] Título:Comparing the action of HT61 and chlorhexidine on natural and model Staphylococcus aureus membranes.
[So] Source:J Antibiot (Tokyo);70(10):1020-1025, 2017 Oct.
[Is] ISSN:0021-8820
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:HT61 and chlorhexidine (CHX) are both putative membrane-active antimicrobials, which non-specifically target the anionic lipids abundant in bacterial membranes. In model systems, the ability of these antimicrobials to partition into lipid monolayers and increase the permeability of lipid bilayers is dependent upon the presence and proportion of anionic lipids such as phosphatidylglycerol. Despite their apparent similarity in membrane affinity, we have found that HT61 and CHX differ in the extent to which they affect membrane integrity. HT61 was found to be capable of severely disrupting the lipid bilayer, resulting in lysis of Staphylococcus aureus membranes and the release of ATP from protoplasts. CHX, by contrast, does not disrupt the lipid bilayer to a sufficiently large degree to result in lysis of the membrane or release of ATP from S. aureus protoplasts. This suggests that although antimicrobials that interact with the membrane often have a common target, the action they have on the membrane may differ widely and may not be the primary mode of action of the antimicrobial.
[Mh] Termos MeSH primário: Anti-Infecciosos Locais/farmacologia
Membrana Celular/efeitos dos fármacos
Clorexidina/farmacologia
Quinolinas/farmacologia
Staphylococcus aureus/efeitos dos fármacos
[Mh] Termos MeSH secundário: Bacteriólise
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Infective Agents, Local); 0 (HT61 compound); 0 (Quinolines); R4KO0DY52L (Chlorhexidine)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171010
[Lr] Data última revisão:
171010
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170803
[St] Status:MEDLINE
[do] DOI:10.1038/ja.2017.90


  5 / 3297 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28733487
[Au] Autor:Carson WF; Cavassani KA; Soares EM; Hirai S; Kittan NA; Schaller MA; Scola MM; Joshi A; Matsukawa A; Aronoff DM; Johnson CN; Dou Y; Gallagher KA; Kunkel SL
[Ad] Endereço:Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109; slkunkel@umich.edu.
[Ti] Título:The STAT4/MLL1 Epigenetic Axis Regulates the Antimicrobial Functions of Murine Macrophages.
[So] Source:J Immunol;199(5):1865-1874, 2017 Sep 01.
[Is] ISSN:1550-6606
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Macrophages are critical immune cells for the clearance of microbial pathogens and cellular debris from peripheral tissues. Macrophage inflammatory responses are governed by gene expression patterns, and these patterns are often subject to epigenetic control. Chromatin modifications, such as histone methylation, regulate gene accessibility in macrophages, and macrophage polarization is governed in part by the expression and function of chromatin-modifying enzymes. The histone methyltransferase mixed-lineage leukemia 1 (MLL1) preferentially modifies lysine residue 4 on the unstructured protein tail of histone H3. MLL1 expression and function have been shown to be governed by signal transduction pathways that are activated by inflammatory stimuli, such as NF-κB. Therefore, we sought to investigate the role of MLL1 in mediating macrophage inflammatory responses. Bone marrow-derived macrophages from mice with a targeted MLL1 gene knockout (Lys2-Cre MLL1 ) exhibited decreased proinflammatory gene expression with concurrent decreases in activating histone methylation. However, MLL1-deficient macrophages also exhibited increased phagocytic and bacterial killing activity in vitro. RNA profiling of MLL1-knockout macrophages identified numerous genes involved with inflammatory responses whose expression was altered in response to TLR ligands or proinflammatory cytokines, including STAT4. STAT4-dependent cytokines, such as type I IFNs were able to drive MLL1 expression in macrophages, and MLL1-knockout macrophages exhibited decreased activating histone methylation in the STAT4 promoter. These results implicate an important role for MLL1-dependent epigenetic regulation of macrophage antimicrobial functions.
[Mh] Termos MeSH primário: Epigênese Genética/imunologia
Histona-Lisina N-Metiltransferase/metabolismo
Infecção/imunologia
Macrófagos/imunologia
Proteína de Leucina Linfoide-Mieloide/metabolismo
Fator de Transcrição STAT4/metabolismo
[Mh] Termos MeSH secundário: Animais
Bacteriólise
Células Cultivadas
Montagem e Desmontagem da Cromatina
Regulação da Expressão Gênica
Histona-Lisina N-Metiltransferase/genética
Histonas/metabolismo
Imunidade Inata
Camundongos
Camundongos Endogâmicos C57BL
Camundongos Knockout
Proteína de Leucina Linfoide-Mieloide/genética
NF-kappa B/metabolismo
Fator de Transcrição STAT4/genética
Transdução de Sinais
Transcriptoma
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Histones); 0 (NF-kappa B); 0 (STAT4 Transcription Factor); 149025-06-9 (Myeloid-Lymphoid Leukemia Protein); EC 2.1.1.43 (Histone-Lysine N-Methyltransferase); EC 2.1.1.43 (Mll protein, mouse)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170929
[Lr] Data última revisão:
170929
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:170723
[St] Status:MEDLINE
[do] DOI:10.4049/jimmunol.1601272


  6 / 3297 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28431999
[Au] Autor:Joshi H; Jain V
[Ad] Endereço:Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India.
[Ti] Título:Novel method to rapidly and efficiently lyse Escherichia coli for the isolation of recombinant protein.
[So] Source:Anal Biochem;528:1-6, 2017 Jul 01.
[Is] ISSN:1096-0309
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Rapid and high-throughput protein purification methods are required to explore structure and function of several uncharacterized proteins. Isolation of recombinant protein expressed in Escherichia coli strain BL21 (DE3) depends largely on the efficient and speedy bacterial cell lysis, which is considered as the bottleneck during protein purification. Cells are usually lysed by either sonication or high pressure homogenization, both of which are slow, require special equipment, lead to heat generation, and may result in loss of protein's biological activity. We report here a novel method to lyse E. coli, which is rapid, and results in high yield of isolated protein. Here, we have carried out intracellular expression of lysozyme domain (LD) of mycobacteriophage D29 endolysin. LD remains non-toxic until chloroform is added into the culture medium that permeabilizes bacterial cell membrane and allows the diffusion of LD to the peptidoglycan layer causing latter's degradation ensuing cell lysis. Our method efficiently lyses E. coli in short duration. As a proof-of-concept, we demonstrate large scale isolation and purification of α subunit of E. coli RNA polymerase and GFP, when they are co-expressed with LD. We believe that our method will be adopted easily in high-throughput as well as large scale protein isolation experiments.
[Mh] Termos MeSH primário: Bacteriólise
Endopeptidases/metabolismo
Escherichia coli
Proteínas Recombinantes/isolamento & purificação
[Mh] Termos MeSH secundário: Cromatografia de Afinidade
Clonagem Molecular
RNA Polimerases Dirigidas por DNA/genética
RNA Polimerases Dirigidas por DNA/isolamento & purificação
Endopeptidases/química
Escherichia coli/enzimologia
Escherichia coli/genética
Escherichia coli/metabolismo
Expressão Gênica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Recombinant Proteins); EC 2.7.7.6 (DNA-Directed RNA Polymerases); EC 2.7.7.6 (RNA polymerase alpha subunit); EC 3.4.- (Endopeptidases); EC 3.4.99.- (endolysin)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170530
[Lr] Data última revisão:
170530
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170423
[St] Status:MEDLINE


  7 / 3297 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28409543
[Au] Autor:Nandi A; Bishayi B
[Ad] Endereço:Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, West Bengal, India.
[Ti] Título:CCR-2 neutralization augments murine fresh BMC activation by Staphylococcus aureus via two distinct mechanisms: at the level of ROS production and cytokine response.
[So] Source:Innate Immun;23(4):345-372, 2017 May.
[Is] ISSN:1753-4267
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:CCR-2 signaling regulates recruitment of monocytes from the bone marrow into the bloodstream and then to sites of infection. We sought to determine whether CCL-2/CCR-2 signaling is involved in the killing of Staphylococcus aureus by murine bone marrow cells (BMCs). The intermittent link of reactive oxygen species (ROS)-NF-κB/p38-MAPK-mediated CCL-2 production in CCR-2 signaling prompted us to determine whether neutralization of CCR-2 augments the response of murine fresh BMCs (FBMCs) after S. aureus infection. It was observed that anti-CCR-2 Ab-treated FBMCs released fewer ROS on encountering S. aureus infection than CCR-2 non-neutralized FBMCs, also correlating with reduced killing of S. aureus in CCR-2 neutralized FBMCs. Staphylococcal catalase and SOD were also found to play a role in protecting S. aureus from the ROS-mediated killing of FBMC. S. aureus infection of CCR-2 intact FBMCs pre-treated with either NF-κB or p-38-MAPK blocker induced less CCL-2, suggesting that NF-κB or p-38-MAPK is required for CCL-2 production by FBMCs. Moreover, blocking of CCR-2 along with NF-κB or p-38-MAPK resulted in elevated CCL-2 production and reduced CCR-2 expression. Inhibition of CCR-2 impairs the response of murine BMCs to S. aureus infection by attenuation ROS production and modulating the cytokine response.
[Mh] Termos MeSH primário: Bacteriólise/efeitos dos fármacos
Células da Medula Óssea/fisiologia
Monócitos/fisiologia
Infecções Estafilocócicas/imunologia
Staphylococcus aureus/imunologia
[Mh] Termos MeSH secundário: Animais
Anticorpos Neutralizantes/farmacologia
Células da Medula Óssea/efeitos dos fármacos
Diferenciação Celular/efeitos dos fármacos
Movimento Celular/efeitos dos fármacos
Células Cultivadas
Citocinas/metabolismo
Seres Humanos
Masculino
Camundongos
Monócitos/efeitos dos fármacos
Estresse Oxidativo/efeitos dos fármacos
Espécies Reativas de Oxigênio/metabolismo
Receptores CCR2/metabolismo
Transdução de Sinais/efeitos dos fármacos
Infecções Estafilocócicas/tratamento farmacológico
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antibodies, Neutralizing); 0 (Ccr2 protein, mouse); 0 (Cytokines); 0 (Reactive Oxygen Species); 0 (Receptors, CCR2)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170512
[Lr] Data última revisão:
170512
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170415
[St] Status:MEDLINE
[do] DOI:10.1177/1753425917697806


  8 / 3297 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28409541
[Au] Autor:Park M; Liu RW; An H; Geczy CL; Thomas PS; Tedla N
[Ad] Endereço:1 Mechanisms of Diseases Translational Research, University of New South Wales, School of Medical Sciences, Department of Pathology, Sydney, Australia.
[Ti] Título:A dual positive and negative regulation of monocyte activation by leukocyte Ig-like receptor B4 depends on the position of the tyrosine residues in its ITIMs.
[So] Source:Innate Immun;23(4):381-391, 2017 May.
[Is] ISSN:1753-4267
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The leukocyte Ig-like receptor B4 (LILRB4) is an inhibitory cell surface receptor, primarily expressed on mono-myeloid cells. It contains 2 C-type Ig-like extracellular domains and a long cytoplasmic domain that contains three intracellular immunoreceptor tyrosine-based inhibitory motifs (ITIMs). Data suggest that LILRB4 suppresses Fc receptor-dependent monocyte functions via its ITIMs, but relative contributions of the three ITIMs are not characterised. To address this, tyrosine (Tyr) residues at positions 337, 389 and 419 were single, double or triple mutated to phenylalanine and stably transfected into a human monocytic cell line, THP-1. Intact Tyr was sufficient to maximally inhibit FcγRI-mediated TNF-α production in THP-1 cells, but, paradoxically, Tyr significantly enhanced TNF-α production. In contrast, bactericidal activity was significantly enhanced in mutants containing Tyr , while Tyr markedly inhibited bacteria killing. Taken together, these results indicate that LILRB4 might have dual inhibitory and activating functions, depending on the position of the functional tyrosine residues in its ITIMs and/or the nature of the stimuli.
[Mh] Termos MeSH primário: Monócitos/fisiologia
Mutação/genética
Células Mieloides/fisiologia
Domínios Proteicos/genética
Receptores de Superfície Celular/metabolismo
Tirosina/genética
[Mh] Termos MeSH secundário: Bacteriólise/genética
Linhagem Celular
Seres Humanos
Imunomodulação
Mutagênese Sítio-Dirigida
Fosforilação
Receptores de Superfície Celular/genética
Receptores de IgG/metabolismo
Transdução de Sinais
Fator de Necrose Tumoral alfa/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (FCGR1A protein, human); 0 (LILRB4 protein, human); 0 (Receptors, Cell Surface); 0 (Receptors, IgG); 0 (Tumor Necrosis Factor-alpha); 42HK56048U (Tyrosine)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170512
[Lr] Data última revisão:
170512
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170415
[St] Status:MEDLINE
[do] DOI:10.1177/1753425917699465


  9 / 3297 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28396351
[Au] Autor:Chamakura KR; Tran JS; Young R
[Ad] Endereço:Center for Phage Technology, Texas A&M AgriLife, Texas A&M University, College Station, Texas, USA.
[Ti] Título:MS2 Lysis of Escherichia coli Depends on Host Chaperone DnaJ.
[So] Source:J Bacteriol;199(12), 2017 Jun 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The L protein of the single-stranded RNA phage MS2 causes lysis of without inducing bacteriolytic activity or inhibiting net peptidoglycan (PG) synthesis. To find host genes required for L-mediated lysis, spontaneous Ill ( nsensitivity to ysis) mutants were selected as survivors of L expression and shown to have a missense change of the highly conserved proline (P330Q) in the C-terminal domain of DnaJ. In the mutant host, L-mediated lysis is completely blocked at 30°C without affecting the intracellular levels of L. At higher temperatures (37°C and 42°C), both lysis and L accumulation are delayed. The lysis block at 30°C in the mutant was recessive and could be suppressed by vercomes ( ) alleles selected for restoration of lysis. All three alleles lack the highly basic N-terminal half of the lysis protein and cause lysis ∼20 min earlier than full-length L. DnaJ was found to form a complex with full-length L. This complex was abrogated by the P330Q mutation and was absent with the L truncations. These results suggest that, in the absence of interaction with DnaJ, the N-terminal domain of L interferes with its ability to bind to its unknown target. The lysis retardation and DnaJ chaperone dependency conferred by the nonessential, highly basic N-terminal domain of L resembles the SlyD chaperone dependency conferred by the highly basic C-terminal domain of the E lysis protein of Ï•X174, suggesting a common theme where single-gene lysis can be modulated by host factors influenced by physiological conditions. Small single-stranded nucleic acid lytic phages ( and ) lyse their host by expressing a single "protein antibiotic." The protein antibiotics from two out of three prototypic small lytic viruses have been shown to inhibit two different steps in the conserved PG biosynthesis pathway. However, the molecular basis of lysis caused by L, the lysis protein of the third prototypic virus, MS2, is unknown. The significance of our research lies in the identification of DnaJ as a chaperone in the MS2 L lysis pathway and the identification of the minimal lytic domain of MS2 L. Additionally, our research highlights the importance of the highly conserved P330 residue in the C-terminal domain of DnaJ for specific protein interactions.
[Mh] Termos MeSH primário: Bacteriólise
Proteínas de Escherichia coli/metabolismo
Escherichia coli/virologia
Proteínas de Choque Térmico HSP40/metabolismo
Interações Hospedeiro-Parasita
Levivirus/crescimento & desenvolvimento
Proteínas Virais/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Escherichia coli/genética
Proteínas de Choque Térmico HSP40/genética
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DnaJ protein, E coli); 0 (Escherichia coli Proteins); 0 (HSP40 Heat-Shock Proteins); 0 (Viral Proteins)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171126
[Lr] Data última revisão:
171126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170412
[St] Status:MEDLINE


  10 / 3297 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28369562
[Au] Autor:Stanczak-Mrozek KI; Laing KG; Lindsay JA
[Ad] Endereço:Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK.
[Ti] Título:Resistance gene transfer: induction of transducing phage by sub-inhibitory concentrations of antimicrobials is not correlated to induction of lytic phage.
[So] Source:J Antimicrob Chemother;72(6):1624-1631, 2017 Jun 01.
[Is] ISSN:1460-2091
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Objectives: Horizontal gene transfer of antimicrobial resistance (AMR) genes between clinical isolates via transduction is poorly understood. MRSA are opportunistic pathogens resistant to all classes of antimicrobial agents but currently no strains are fully drug resistant. AMR gene transfer between Staphylococcus aureus isolates is predominantly due to generalized transduction via endogenous bacteriophage, and recent studies have suggested transfer is elevated during host colonization. The aim was to investigate whether exposure to sub-MIC concentrations of antimicrobials triggers bacteriophage induction and/or increased efficiency of AMR gene transfer. Methods: Isolates from MRSA carriers were exposed to nine antimicrobials and supernatants were compared for lytic phage particles and ability to transfer an AMR gene. A new technology, droplet digital PCR, was used to measure the concentration of genes in phage particles. Results: All antibiotics tested induced lytic phage and AMR gene transduction, although the ratio of transducing particles to lytic particles differed substantially for each antibiotic. Mupirocin induced the highest ratio of transducing versus lytic particles. Gentamicin and novobiocin reduced UV-induced AMR transduction. The genes carried in phage particles correlated with AMR transfer or lytic particle activity, suggesting antimicrobials influence which DNA sequences are packaged into phage particles. Conclusions: Sub-inhibitory antibiotics induce AMR gene transfer between clinical MRSA, while combination therapy with an inhibiting antibiotic could potentially alter AMR gene packaging into phage particles, reducing AMR transfer. In a continually evolving environment, pathogens have an advantage if they can transfer DNA while lowering the risk of lytic death.
[Mh] Termos MeSH primário: Antibacterianos/farmacologia
Bacteriófagos/efeitos dos fármacos
Bacteriófagos/fisiologia
Staphylococcus aureus Resistente à Meticilina/genética
Staphylococcus aureus/genética
Transdução Genética
Ativação Viral
[Mh] Termos MeSH secundário: Bacteriólise
Bacteriófagos/genética
Bacteriófagos/isolamento & purificação
Farmacorresistência Bacteriana Múltipla/genética
Seres Humanos
Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos
Staphylococcus aureus Resistente à Meticilina/virologia
Testes de Sensibilidade Microbiana
Infecções Estafilocócicas/microbiologia
Staphylococcus aureus/efeitos dos fármacos
Staphylococcus aureus/virologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171107
[Lr] Data última revisão:
171107
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170404
[St] Status:MEDLINE
[do] DOI:10.1093/jac/dkx056



página 1 de 330 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde