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Sample records for obligate intracellular bacterial

  1. Proteomic Profiling of the Outer Membrane Fraction of the Obligate Intracellular Bacterial Pathogen Ehrlichia ruminantium

    PubMed Central

    Moumène, Amal; Marcelino, Isabel; Ventosa, Miguel; Gros, Olivier; Lefrançois, Thierry; Vachiéry, Nathalie

    2015-01-01

    The outer membrane proteins (OMPs) of Gram-negative bacteria play a crucial role in virulence and pathogenesis. Identification of these proteins represents an important goal for bacterial proteomics, because it aids in vaccine development. Here, we have developed such an approach for Ehrlichia ruminantium, the obligate intracellular bacterium that causes heartwater. A preliminary whole proteome analysis of elementary bodies, the extracellular infectious form of the bacterium, had been performed previously, but information is limited about OMPs in this organism and about their role in the protective immune response. Identification of OMPs is also essential for understanding Ehrlichia’s OM architecture, and how the bacterium interacts with the host cell environment. First, we developed an OMP extraction method using the ionic detergent sarkosyl, which enriched the OM fraction. Second, proteins were separated via one-dimensional electrophoresis, and digested peptides were analyzed via nano-liquid chromatographic separation coupled with mass spectrometry (LC-MALDI-TOF/TOF). Of 46 unique proteins identified in the OM fraction, 18 (39%) were OMPs, including 8 proteins involved in cell structure and biogenesis, 4 in transport/virulence, 1 porin, and 5 proteins of unknown function. These experimental data were compared to the predicted subcellular localization of the entire E. ruminantium proteome, using three different algorithms. This work represents the most complete proteome characterization of the OM fraction in Ehrlichia spp. The study indicates that suitable subcellular fractionation experiments combined with straightforward computational analysis approaches are powerful for determining the predominant subcellular localization of the experimentally observed proteins. We identified proteins potentially involved in E. ruminantium pathogenesis, which are good novel targets for candidate vaccines. Thus, combining bioinformatics and proteomics, we discovered new OMPs for E. ruminantium that are valuable data for those investigating new vaccines against this organism. In summary, we provide both pioneering data and novel insights into the pathogenesis of this obligate intracellular bacterium. PMID:25710494

  2. Mobile DNA in obligate intracellular bacteria.

    PubMed

    Bordenstein, Seth R; Reznikoff, William S

    2005-09-01

    The small genomes of obligate intracellular bacteria are often presumed to be impervious to mobile DNA and the fluid genetic processes that drive diversification in free-living bacteria. Categorized by reductive evolution and streamlining, the genomes of some obligate intracellular bacteria manifest striking degrees of stability and gene synteny. However, recent findings from complete genome sequences of obligate intracellular species and their mobile genetic associates favour the abandonment of these wholesale terms for a more complex and tantalizing picture. PMID:16138097

  3. Secretome of obligate intracellular Rickettsia

    PubMed Central

    Gillespie, Joseph J.; Kaur, Simran J.; Rahman, M. Sayeedur; Rennoll-Bankert, Kristen; Sears, Khandra T.; Beier-Sexton, Magda; Azad, Abdu F.

    2014-01-01

    The genus Rickettsia (Alphaproteobacteria, Rickettsiales, Rickettsiaceae) is comprised of obligate intracellular parasites, with virulent species of interest both as causes of emerging infectious diseases and for their potential deployment as bioterrorism agents. Currently, there are no effective commercially available vaccines, with treatment limited primarily to tetracycline antibiotics, although others (e.g. josamycin, ciprofloxacin, chloramphenicol, and azithromycin) are also effective. Much of the recent research geared toward understanding mechanisms underlying rickettsial pathogenicity has centered on characterization of secreted proteins that directly engage eukaryotic cells. Herein, we review all aspects of the Rickettsia secretome, including six secretion systems, 19 characterized secretory proteins, and potential moonlighting proteins identified on surfaces of multiple Rickettsia species. Employing bioinformatics and phylogenomics, we present novel structural and functional insight on each secretion system. Unexpectedly, our investigation revealed that the majority of characterized secretory proteins have not been assigned to their cognate secretion pathways. Furthermore, for most secretion pathways, the requisite signal sequences mediating translocation are poorly understood. As a blueprint for all known routes of protein translocation into host cells, this resource will assist research aimed at uniting characterized secreted proteins with their apposite secretion pathways. Furthermore, our work will help in the identification of novel secreted proteins involved in rickettsial ‘life on the inside’. PMID:25168200

  4. Genetic Systems for Studying Obligate Intracellular Pathogens: An Update

    PubMed Central

    Wood, David O.; Wood, Raphael R.; Tucker, Aimee M.

    2013-01-01

    Rapid advancements in the genetic manipulation of obligate intracellular bacterial pathogens have been made over the past two years. In this paper we attempt to summarize the work published since 2011 that documents these exciting accomplishments. While each genus comprising this diverse group of pathogens poses unique problems, requiring modifications of established techniques and the introduction of new tools, all appear amenable to genetic analysis. Significantly, the field is moving forward from a focus on the identification and development of genetic techniques to their application in addressing critical questions related to mechanisms of bacterial pathogenicity and the requirements of obligate intracellular growth. PMID:24581687

  5. The cell wall of the obligate intracellular bacterial parasite of small free-living amoebae. I. Morphology and chemical composition of the rigid layer and peptidoglycan.

    PubMed

    Drozański, W; Drozańska, D; Wicińska, M

    1984-01-01

    The obligate intracellular bacterial parasite "OIBP" of small free-living amoebae, discovered by Drozański (1956) was propagated in axenic culture of Acanthamoeba castellanii. The peptidoglycan prepared by chemical extraction of intact cells of the bacterium was examined in a transmission electron microscope and analysed chemically. Electron micrographs of heavy metal shadowed preparations revealed a bag-shaped membraneous structure resembling that of the peptidoglycan sacculi of Escherichia coli and the other gram-negative bacteria so far studied. The peptidoglycan may be present in a lipoprotein-peptidoglycan complex, as proteolytic enzyme treatment resulted in changes of the ultrastructure and in chemical composition. Results of chemical analysis of acid hydrolysed peptidoglycan indicate the presence of two aminosugars; glucosamine and muramic acid and also significant amounts of glycine together with three major amino acids; alanine, glutamic acid and diaminopimelic acid. It was shown that the peptidoglycan was, however, resistant to the hydrolytic action of egg-white lysozyme and to the lysosomal endo N-acetylmuramidases of amoebael origin. PMID:6083704

  6. Adaptive Immunity to the Obligate Intracellular Pathogen Coxiella burnetii

    PubMed Central

    Shannon, Jeffrey G.; Heinzen, Robert A.

    2009-01-01

    Coxiella burnetii is an obligate intracellular bacterial pathogen that causes the zoonosis Q fever. While an effective whole-cell vaccine against Q fever exists, the vaccine has limitations in being highly reactogenic in sensitized individuals. Thus, a safe and effective vaccine based on recombinant protein antigen (Ag) is desirable. To achieve this goal, a better understanding of the host response to primary infection and the precise mechanisms involved in protective immunity to C. burnetii are needed. This review summarizes our current understanding of adaptive immunity to C. burnetii with a focus on recent developments in the field. PMID:18813881

  7. Microsporidian genome analysis reveals evolutionary strategies for obligate intracellular growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microsporidia comprise a large phylum of obligate intracellular eukaryotes that are fungalrelated parasites responsible for widespread disease, and here we address questions about microsporidia biology and evolution. We sequenced three microsporidian genomes from two species, Nematocida parisii and...

  8. Metabolic Interdependence of Obligate Intracellular Bacteria and Their Insect Hosts†

    PubMed Central

    Zientz, Evelyn; Dandekar, Thomas; Gross, Roy

    2004-01-01

    Mutualistic associations of obligate intracellular bacteria and insects have attracted much interest in the past few years due to the evolutionary consequences for their genome structure. However, much less attention has been paid to the metabolic ramifications for these endosymbiotic microorganisms, which have to compete with but also to adapt to another metabolism—that of the host cell. This review attempts to provide insights into the complex physiological interactions and the evolution of metabolic pathways of several mutualistic bacteria of aphids, ants, and tsetse flies and their insect hosts. PMID:15590782

  9. Molecular pathogenesis of the obligate intracellular bacterium Coxiella burnetii

    PubMed Central

    van Schaik, Erin J.; Chen, Chen; Mertens, Katja; Weber, Mary M.; Samuel, James E.

    2014-01-01

    The agent of Q fever, Coxiella burnetii, is an obligate intracellular bacterium that causes acute and chronic infections. The study of C. burnetii pathogenesis has benefited from two recent fundamental advances: improved genetic tools and the ability to grow the bacterium in extracellular media. In this Review, we describe how these recent advances have improved our understanding of C. burnetii invasion and host cell modulation, including the formation of replication-permissive Coxiella-containing vacuoles. Furthermore, we describe the Dot/Icm (defect in organelle trafficking/intracellular multiplication) system, which is used by C. burnetii to secrete a range of effector proteins into the host cell, and we discuss the role of these effectors in remodelling the host cell. PMID:23797173

  10. Evolutionary Genomics of a Temperate Bacteriophage in an Obligate Intracellular Bacteria (Wolbachia)

    PubMed Central

    Kent, Bethany N.; Funkhouser, Lisa J.; Setia, Shefali; Bordenstein, Seth R.

    2011-01-01

    Genome evolution of bacteria is usually influenced by ecology, such that bacteria with a free-living stage have large genomes and high rates of horizontal gene transfer, while obligate intracellular bacteria have small genomes with typically low amounts of gene exchange. However, recent studies indicate that obligate intracellular species that host-switch frequently harbor agents of horizontal transfer such as mobile elements. For example, the temperate double-stranded DNA bacteriophage WO in Wolbachia persistently transfers between bacterial coinfections in the same host. Here we show that despite the phage's rampant mobility between coinfections, the prophage's genome displays features of constraint related to its intracellular niche. First, there is always at least one intact prophage WO and usually several degenerate, independently-acquired WO prophages in each Wolbachia genome. Second, while the prophage genomes are modular in composition with genes of similar function grouping together, the modules are generally not interchangeable with other unrelated phages and thus do not evolve by the Modular Theory. Third, there is an unusual core genome that strictly consists of head and baseplate genes; other gene modules are frequently deleted. Fourth, the prophage recombinases are diverse and there is no conserved integration sequence. Finally, the molecular evolutionary forces acting on prophage WO are point mutation, intragenic recombination, deletion, and purifying selection. Taken together, these analyses indicate that while lateral transfer of phage WO is pervasive between Wolbachia with occasional new gene uptake, constraints of the intracellular niche obstruct extensive mixture between WO and the global phage population. Although the Modular Theory has long been considered the paradigm of temperate bacteriophage evolution in free-living bacteria, it appears irrelevant in phages of obligate intracellular bacteria. PMID:21949820

  11. Improved Quantification, Propagation, Purification and Storage of the Obligate Intracellular Human Pathogen Orientia tsutsugamushi

    PubMed Central

    Giengkam, Suparat; Blakes, Alex; Utsahajit, Peemdej; Chaemchuen, Suwittra; Atwal, Sharanjeet; Blacksell, Stuart D.; Paris, Daniel H.; Day, Nicholas P. J.; Salje, Jeanne

    2015-01-01

    Background Scrub typhus is a leading cause of serious febrile illness in rural Southeast Asia. The causative agent, Orientia tsutsugamushi, is an obligate intracellular bacterium that is transmitted to humans by the bite of a Leptotrombidium mite. Research into the basic mechanisms of cell biology and pathogenicity of O. tsutsugamushi has lagged behind that of other important human pathogens. One reason for this is that O. tsutsugamushi is an obligate intracellular bacterium that can only be cultured in mammalian cells and that requires specific methodologies for propagation and analysis. Here, we have performed a body of work designed to improve methods for quantification, propagation, purification and long-term storage of this important but neglected human pathogen. These results will be useful to other researchers working on O. tsutsugamushi and also other obligate intracellular pathogens such as those in the Rickettsiales and Chlamydiales families. Methodology A clinical isolate of O. tsutsugamushi was grown in cultured mouse embryonic fibroblast (L929) cells. Bacterial growth was measured using an O. tsutsugamushi-specific qPCR assay. Conditions leading to improvements in viability and growth were monitored in terms of the effect on bacterial cell number after growth in cultured mammalian cells. Key results Development of a standardised growth assay to quantify bacterial replication and viability in vitro. Quantitative comparison of different DNA extraction methods. Quantification of the effect on growth of FBS concentration, daunorubicin supplementation, media composition, host cell confluence at infection and frequency of media replacement. Optimisation of bacterial purification including a comparison of host cell lysis methods, purification temperature, bacterial yield calculations and bacterial pelleting at different centrifugation speeds. Quantification of bacterial viability loss after long term storage and freezing under a range of conditions including different freezing buffers and different rates of freezing. Conclusions Here we present a standardised method for comparing the viability of O. tsutsugamushi after purification, treatment and propagation under various conditions. Taken together, we present a body of data to support improved techniques for propagation, purification and storage of this organism. This data will be useful both for improving clinical isolation rates as well as performing in vitro cell biology experiments. PMID:26317517

  12. Microsporidian genome analysis reveals evolutionary strategies for obligate intracellular growth.

    PubMed

    Cuomo, Christina A; Desjardins, Christopher A; Bakowski, Malina A; Goldberg, Jonathan; Ma, Amy T; Becnel, James J; Didier, Elizabeth S; Fan, Lin; Heiman, David I; Levin, Joshua Z; Young, Sarah; Zeng, Qiandong; Troemel, Emily R

    2012-12-01

    Microsporidia comprise a large phylum of obligate intracellular eukaryotes that are fungal-related parasites responsible for widespread disease, and here we address questions about microsporidia biology and evolution. We sequenced three microsporidian genomes from two species, Nematocida parisii and Nematocida sp1, which are natural pathogens of Caenorhabditis nematodes and provide model systems for studying microsporidian pathogenesis. We performed deep sequencing of transcripts from a time course of N. parisii infection. Examination of pathogen gene expression revealed compact transcripts and a dramatic takeover of host cells by Nematocida. We also performed phylogenomic analyses of Nematocida and other microsporidian genomes to refine microsporidian phylogeny and identify evolutionary events of gene loss, acquisition, and modification. In particular, we found that all microsporidia lost the tumor-suppressor gene retinoblastoma, which we speculate could accelerate the parasite cell cycle and increase the mutation rate. We also found that microsporidia acquired transporters that could import nucleosides to fuel rapid growth. In addition, microsporidian hexokinases gained secretion signal sequences, and in a functional assay these were sufficient to export proteins out of the cell; thus hexokinase may be targeted into the host cell to reprogram it toward biosynthesis. Similar molecular changes appear during formation of cancer cells and may be evolutionary strategies adopted independently by microsporidia to proliferate rapidly within host cells. Finally, analysis of genome polymorphisms revealed evidence for a sexual cycle that may provide genetic diversity to alleviate problems caused by clonal growth. Together these events may explain the emergence and success of these diverse intracellular parasites. PMID:22813931

  13. Microsporidian genome analysis reveals evolutionary strategies for obligate intracellular growth

    PubMed Central

    Cuomo, Christina A.; Desjardins, Christopher A.; Bakowski, Malina A.; Goldberg, Jonathan; Ma, Amy T.; Becnel, James J.; Didier, Elizabeth S.; Fan, Lin; Heiman, David I.; Levin, Joshua Z.; Young, Sarah; Zeng, Qiandong; Troemel, Emily R.

    2012-01-01

    Microsporidia comprise a large phylum of obligate intracellular eukaryotes that are fungal-related parasites responsible for widespread disease, and here we address questions about microsporidia biology and evolution. We sequenced three microsporidian genomes from two species, Nematocida parisii and Nematocida sp1, which are natural pathogens of Caenorhabditis nematodes and provide model systems for studying microsporidian pathogenesis. We performed deep sequencing of transcripts from a time course of N. parisii infection. Examination of pathogen gene expression revealed compact transcripts and a dramatic takeover of host cells by Nematocida. We also performed phylogenomic analyses of Nematocida and other microsporidian genomes to refine microsporidian phylogeny and identify evolutionary events of gene loss, acquisition, and modification. In particular, we found that all microsporidia lost the tumor-suppressor gene retinoblastoma, which we speculate could accelerate the parasite cell cycle and increase the mutation rate. We also found that microsporidia acquired transporters that could import nucleosides to fuel rapid growth. In addition, microsporidian hexokinases gained secretion signal sequences, and in a functional assay these were sufficient to export proteins out of the cell; thus hexokinase may be targeted into the host cell to reprogram it toward biosynthesis. Similar molecular changes appear during formation of cancer cells and may be evolutionary strategies adopted independently by microsporidia to proliferate rapidly within host cells. Finally, analysis of genome polymorphisms revealed evidence for a sexual cycle that may provide genetic diversity to alleviate problems caused by clonal growth. Together these events may explain the emergence and success of these diverse intracellular parasites. PMID:22813931

  14. Disrupting Protein Expression with Peptide Nucleic Acids Reduces Infection by Obligate Intracellular Rickettsia

    PubMed Central

    Pelc, Rebecca S.; McClure, Jennifer C.; Kaur, Simran J.; Sears, Khandra T.; Rahman, M. Sayeedur; Ceraul, Shane M.

    2015-01-01

    Peptide Nucleic Acids (PNAs) are single-stranded synthetic nucleic acids with a pseudopeptide backbone in lieu of the phosphodiester linked sugar and phosphate found in traditional oligos. PNA designed complementary to the bacterial Shine-Dalgarno or start codon regions of mRNA disrupts translation resulting in the transient reduction in protein expression. This study examines the use of PNA technology to interrupt protein expression in obligate intracellular Rickettsia sp. Their historically intractable genetic system limits characterization of protein function. We designed PNA targeting mRNA for rOmpB from Rickettsia typhi and rickA from Rickettsia montanensis, ubiquitous factors important for infection. Using an in vitro translation system and competitive binding assays, we determined that our PNAs bind target regions. Electroporation of R. typhi and R. montanensis with PNA specific to rOmpB and rickA, respectively, reduced the bacteria’s ability to infect host cells. These studies open the possibility of using PNA to suppress protein synthesis in obligate intracellular bacteria. PMID:25781160

  15. Macrophage cell death upon intracellular bacterial infection

    PubMed Central

    Lai, Xin-He; Xu, Yunsheng; Chen, Xiao-Ming; Ren, Yi

    2015-01-01

    Macrophage-pathogen interaction is a complex process and the outcome of this tag-of-war for both sides is to live or die. Without attempting to be comprehensive, this review will discuss the complexity and significance of the interaction outcomes between macrophages and some facultative intracellular bacterial pathogens as exemplified by Francisella, Salmonella, Shigella and Yersinia. Upon bacterial infection, macrophages can die by a variety of ways, such as apoptosis, autophagic cell death, necrosis, necroptosis, oncosis, pyronecrosis, pyroptosis etc, which is the focus of this review. PMID:26690967

  16. Rickettsia Phylogenomics: Unwinding the Intricacies of Obligate Intracellular Life

    PubMed Central

    Gillespie, Joseph J.; Williams, Kelly; Shukla, Maulik; Snyder, Eric E.; Nordberg, Eric K.; Ceraul, Shane M.; Dharmanolla, Chitti; Rainey, Daphne; Soneja, Jeetendra; Shallom, Joshua M.; Vishnubhat, Nataraj Dongre; Wattam, Rebecca; Purkayastha, Anjan; Czar, Michael; Crasta, Oswald; Setubal, Joao C.; Azad, Abdu F.; Sobral, Bruno S.

    2008-01-01

    Background Completed genome sequences are rapidly increasing for Rickettsia, obligate intracellular α-proteobacteria responsible for various human diseases, including epidemic typhus and Rocky Mountain spotted fever. In light of phylogeny, the establishment of orthologous groups (OGs) of open reading frames (ORFs) will distinguish the core rickettsial genes and other group specific genes (class 1 OGs or C1OGs) from those distributed indiscriminately throughout the rickettsial tree (class 2 OG or C2OGs). Methodology/Principal Findings We present 1823 representative (no gene duplications) and 259 non-representative (at least one gene duplication) rickettsial OGs. While the highly reductive (∼1.2 MB) Rickettsia genomes range in predicted ORFs from 872 to 1512, a core of 752 OGs was identified, depicting the essential Rickettsia genes. Unsurprisingly, this core lacks many metabolic genes, reflecting the dependence on host resources for growth and survival. Additionally, we bolster our recent reclassification of Rickettsia by identifying OGs that define the AG (ancestral group), TG (typhus group), TRG (transitional group), and SFG (spotted fever group) rickettsiae. OGs for insect-associated species, tick-associated species and species that harbor plasmids were also predicted. Through superimposition of all OGs over robust phylogeny estimation, we discern between C1OGs and C2OGs, the latter depicting genes either decaying from the conserved C1OGs or acquired laterally. Finally, scrutiny of non-representative OGs revealed high levels of split genes versus gene duplications, with both phenomena confounding gene orthology assignment. Interestingly, non-representative OGs, as well as OGs comprised of several gene families typically involved in microbial pathogenicity and/or the acquisition of virulence factors, fall predominantly within C2OG distributions. Conclusion/Significance Collectively, we determined the relative conservation and distribution of 14354 predicted ORFs from 10 rickettsial genomes across robust phylogeny estimation. The data, available at PATRIC (PathoSystems Resource Integration Center), provide novel information for unwinding the intricacies associated with Rickettsia pathogenesis, expanding the range of potential diagnostic, vaccine and therapeutic targets. PMID:19194535

  17. Iron depletion limits intracellular bacterial growth in macrophages

    PubMed Central

    Paradkar, Prasad N.; De Domenico, Ivana; Durchfort, Nina; Zohn, Irene; Kaplan, Jerry

    2008-01-01

    Many intracellular pathogens infect macrophages and these pathogens require iron for growth. Here we demonstrate in vitro that the intracellular growth of Chlamydia psittaci, trachomatis, and Legionella pneumophila is regulated by the levels of intracellular iron. Macrophages that express cell surface ferroportin, the only known cellular iron exporter, limit the intracellular growth of these bacteria. Hepcidin is an antimicrobial peptide secreted by the liver in response to inflammation. Hepcidin binds to ferroportin mediating its internalization and degradation. Addition of hepcidin to infected macrophages enhanced the intracellular growth of these pathogens. Macrophages from flatiron mice, a strain heterozygous for a loss-of-function ferroportin mutation, showed enhanced intracellular bacterial growth independent of the presence of exogenous hepcidin. Macrophages, from wild-type or flatiron mice, incubated with the oral iron chelator deferriprone or desferasirox showed reduced intracellular bacterial growth suggesting that these chelators might be therapeutic in chronic intracellular bacterial infections. PMID:18369153

  18. Dining in: intracellular bacterial pathogen interplay with autophagy.

    PubMed

    Winchell, Caylin G; Steele, Shaun; Kawula, Tom; Voth, Daniel E

    2016-02-01

    Intracellular bacterial pathogens have evolved many ways to manipulate host cells for successful infection. Many of these pathogens use specialized secretion systems to inject bacterial proteins into the host cytosol that manipulate cellular processes to favor infection. Autophagy is a eukaryotic cellular remodeling process with a critical role in many diseases, including bacterial clearance. A growing field of research highlights mechanisms used by intracellular bacteria to manipulate autophagy as a pro-survival strategy. This review focuses on a select group of bacterial pathogens with diverse intracellular lifestyles that exploit autophagy-derived nutrients and membrane for survival. This group of pathogens uses secretion systems and specific effectors to subvert distinct components of autophagy. By understanding how intracellular pathogens manipulate autophagy, we gain insight not only into bacterial pathogenesis but also host cell signaling and autophagolysosome maturation. PMID:26462048

  19. Laser microdissection coupled with RNA-seq analysis of porcine enterocytes infected with an obligate intracellular pathogen (Lawsonia intracellularis)

    PubMed Central

    2013-01-01

    Background Lawsonia intracellularis is an obligate intracellular bacterium and the etiologic agent of proliferative enteropathy. The disease is endemic in pigs, emerging in horses and has been described in various other species including nonhuman primates. Cell proliferation is associated with bacterial replication in enterocyte cytoplasm, but the molecular basis of the host-pathogen interaction is unknown. We used laser capture microdissection coupled with RNA-seq technology to characterize the transcriptional responses of infected enterocytes and the host-pathogen interaction. Results Proliferative enterocytes was associated with activation of transcription, protein biosynthesis and genes acting on the G1 phase of the host cell cycle (Rho family). The lack of differentiation in infected enterocytes was demonstrated by the repression of membrane transporters related to nutrient acquisition. The activation of the copper uptake transporter by infected enterocytes was associated with high expression of the Zn/Cu superoxide dismutase by L. intracellularis. This suggests that the intracellular bacteria incorporate intracytoplasmic copper and express a sophisticated mechanism to cope with oxidative stress. Conclusions The feasibility of coupling microdissection and RNA-seq was demonstrated by characterizing the host-bacterial interactions from a specific cell type in a heterogeneous tissue. High expression of L. intracellularis genes encoding hypothetical proteins and activation of host Rho genes infers the role of unrecognized bacterial cyclomodulins in the pathogenesis of proliferative enteropathy. PMID:23800029

  20. Transient Transfection and Expression in the Obligate Intracellular Parasite Toxoplasma gondii

    NASA Astrophysics Data System (ADS)

    Soldati, Dominique; Boothroyd, John C.

    1993-04-01

    Toxoplasma gondii is a protozoan pathogen that produces severe disease in humans and animals. This obligate intracellular parasite provides an excellent model for the study of how such pathogens are able to invade, survive, and replicate intracellularly. DNA encoding chloramphenicol acetyltransferase was introduced into T. gondii and transiently expressed with the use of three vectors based on different Toxoplasma genes. The ability to introduce genes and have them efficiently and faithfully expressed is an essential tool for understanding the structure-function relation of genes and their products.

  1. The Genome of the Obligate Intracellular Parasite Trachipleistophora hominis: New Insights into Microsporidian Genome Dynamics and Reductive Evolution

    PubMed Central

    Heinz, Eva; Williams, Tom A.; Nakjang, Sirintra; Noël, Christophe J.; Swan, Daniel C.; Goldberg, Alina V.; Harris, Simon R.; Weinmaier, Thomas; Markert, Stephanie; Becher, Dörte; Bernhardt, Jörg; Dagan, Tal; Hacker, Christian; Lucocq, John M.; Schweder, Thomas; Rattei, Thomas; Hall, Neil; Hirt, Robert P.; Embley, T. Martin

    2012-01-01

    The dynamics of reductive genome evolution for eukaryotes living inside other eukaryotic cells are poorly understood compared to well-studied model systems involving obligate intracellular bacteria. Here we present 8.5 Mb of sequence from the genome of the microsporidian Trachipleistophora hominis, isolated from an HIV/AIDS patient, which is an outgroup to the smaller compacted-genome species that primarily inform ideas of evolutionary mode for these enormously successful obligate intracellular parasites. Our data provide detailed information on the gene content, genome architecture and intergenic regions of a larger microsporidian genome, while comparative analyses allowed us to infer genomic features and metabolism of the common ancestor of the species investigated. Gene length reduction and massive loss of metabolic capacity in the common ancestor was accompanied by the evolution of novel microsporidian-specific protein families, whose conservation among microsporidians, against a background of reductive evolution, suggests they may have important functions in their parasitic lifestyle. The ancestor had already lost many metabolic pathways but retained glycolysis and the pentose phosphate pathway to provide cytosolic ATP and reduced coenzymes, and it had a minimal mitochondrion (mitosome) making Fe-S clusters but not ATP. It possessed bacterial-like nucleotide transport proteins as a key innovation for stealing host-generated ATP, the machinery for RNAi, key elements of the early secretory pathway, canonical eukaryotic as well as microsporidian-specific regulatory elements, a diversity of repetitive and transposable elements, and relatively low average gene density. Microsporidian genome evolution thus appears to have proceeded in at least two major steps: an ancestral remodelling of the proteome upon transition to intracellular parasitism that involved reduction but also selective expansion, followed by a secondary compaction of genome architecture in some, but not all, lineages. PMID:23133373

  2. Autophagic clearance of bacterial pathogens: molecular recognition of intracellular microorganisms

    PubMed Central

    Mansilla Pareja, Maria Eugenia; Colombo, Maria I.

    2013-01-01

    Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens, as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection. In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance. PMID:24137567

  3. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites

    PubMed Central

    Woo, Yong H; Ansari, Hifzur; Otto, Thomas D; Klinger, Christen M; Kolisko, Martin; Michálek, Jan; Saxena, Alka; Shanmugam, Dhanasekaran; Tayyrov, Annageldi; Veluchamy, Alaguraj; Ali, Shahjahan; Bernal, Axel; del Campo, Javier; Cihlář, Jaromír; Flegontov, Pavel; Gornik, Sebastian G; Hajdušková, Eva; Horák, Aleš; Janouškovec, Jan; Katris, Nicholas J; Mast, Fred D; Miranda-Saavedra, Diego; Mourier, Tobias; Naeem, Raeece; Nair, Mridul; Panigrahi, Aswini K; Rawlings, Neil D; Padron-Regalado, Eriko; Ramaprasad, Abhinay; Samad, Nadira; Tomčala, Aleš; Wilkes, Jon; Neafsey, Daniel E; Doerig, Christian; Bowler, Chris; Keeling, Patrick J; Roos, David S; Dacks, Joel B; Templeton, Thomas J; Waller, Ross F; Lukeš, Julius; Oborník, Miroslav; Pain, Arnab

    2015-01-01

    The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga. DOI: http://dx.doi.org/10.7554/eLife.06974.001 PMID:26175406

  4. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites.

    PubMed

    Woo, Yong H; Ansari, Hifzur; Otto, Thomas D; Klinger, Christen M; Kolisko, Martin; Michálek, Jan; Saxena, Alka; Shanmugam, Dhanasekaran; Tayyrov, Annageldi; Veluchamy, Alaguraj; Ali, Shahjahan; Bernal, Axel; del Campo, Javier; Cihlář, Jaromír; Flegontov, Pavel; Gornik, Sebastian G; Hajdušková, Eva; Horák, Aleš; Janouškovec, Jan; Katris, Nicholas J; Mast, Fred D; Miranda-Saavedra, Diego; Mourier, Tobias; Naeem, Raeece; Nair, Mridul; Panigrahi, Aswini K; Rawlings, Neil D; Padron-Regalado, Eriko; Ramaprasad, Abhinay; Samad, Nadira; Tomčala, Aleš; Wilkes, Jon; Neafsey, Daniel E; Doerig, Christian; Bowler, Chris; Keeling, Patrick J; Roos, David S; Dacks, Joel B; Templeton, Thomas J; Waller, Ross F; Lukeš, Julius; Oborník, Miroslav; Pain, Arnab

    2015-01-01

    The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga. PMID:26175406

  5. Apoptotic mimicry by an obligate intracellular parasite downregulates macrophage microbicidal activity.

    PubMed

    de Freitas Balanco, J M; Moreira, M E; Bonomo, A; Bozza, P T; Amarante-Mendes, G; Pirmez, C; Barcinski, M A

    2001-11-27

    Programmed cell death by apoptosis of unnecessary or potentially harmful cells is clearly beneficial to multicellular organisms. Proper functioning of such a program demands that the removal of dying cells proceed without an inflammatory reaction. Phosphatidylserine (PS) is one of the ligands displayed by apoptotic cells that participates in their noninflammatory removal when recognized by neighboring phagocytes. PS ligation induces the release of transforming growth factor-beta (TGF-beta), an antiinflammatory cytokine that mediates the suppression of macrophage-mediated inflammation. In Hydra vulgaris, an organism that stands at the base of metazoan evolution, the selective advantage provided by apoptosis lies in the fact that Hydra can survive recycling apoptotic cells by phagocytosis. In unicellular organisms, it has been proposed that altruistic death benefits clonal populations of yeasts and trypanosomatids. Now we show that advantageous features of the apoptotic process can operate without death as the necessary outcome. Leishmania spp are able to evade the killing activity of phagocytes and establish themselves as obligate intracellular parasites. Amastigotes, responsible for disease propagation, similar to apoptotic cells, inhibit macrophage activity by exposing PS. Exposed PS participates in amastigote internalization. Recognition of this moiety by macrophages induces TGF-beta secretion and IL-10 synthesis, inhibits NO production, and increases susceptibility to intracellular leishmanial growth. PMID:11728310

  6. The genome of obligately intracellular Ehrlichia canis revealsthemes of complex membrane structure and immune evasion strategies

    SciTech Connect

    Mavromatis, K.; Kuyler Doyle, C.; Lykidis, A.; Ivanova, N.; Francino, P.; Chain, P.; Shin, M.; Malfatti, S.; Larimer, F.; Copeland,A.; Detter, J.C.; Land, M.; Richardson, P.M.; Yu, X.J.; Walker, D.H.; McBride, J.W.; Kyrpides, N.C.

    2005-09-01

    Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, a-proteobacterium is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, and 17 putative pseudogenes, and a substantial proportion of non-coding sequence (27 percent). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences, and a unique serine-threonine bias associated with the potential for O-glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein families associated with immune evasion were identified, one of which contains poly G:C tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Proteins associated with pathogen-host interactions were identified including a small group of proteins (12) with tandem repeats and another with eukaryotic-like ankyrin domains (7).

  7. Pathogenic Potential of Novel Chlamydiae and Diagnostic Approaches to Infections Due to These Obligate Intracellular Bacteria

    PubMed Central

    Corsaro, Daniele; Greub, Gilbert

    2006-01-01

    Novel chlamydiae are newly recognized members of the phylum Chlamydiales that are only distantly related to the classic Chlamydiaceae, i.e., Chlamydia and Chlamydophila species. They also exibit an obligate biphasic intracellular life cycle within eukaryote host cells. Some of these new chlamydiae are currently considered potential emerging human and/or animal pathogens. Parachlamydia acanthamoebae and Simkania negevensis are both emerging respiratory human pathogens, Waddlia chondrophila could be a novel abortigenic bovine agent, and Piscichlamydia salmonis has recently been identified as an agent of the gill epitheliocystis in the Atlantic salmon. Fritschea spp. and Rhabdochlamydia spp. seem to be confined to arthropods, but some evidence for human exposure exists. In this review, we first summarize the data supporting a pathogenic potential of the novel chlamydiae for humans and other vertebrates and the interactions that most of these chlamydiae have with free-living amoebae. We then review the diagnostic approaches to infections potentially due to the novel chlamydiae, especially focusing on the currently available PCR-based protocols, mammalian cell culture, the amoebal coculture system, and serology. PMID:16614250

  8. Metabolic host responses to infection by intracellular bacterial pathogens

    PubMed Central

    Eisenreich, Wolfgang; Heesemann, Jürgen; Rudel, Thomas; Goebel, Werner

    2013-01-01

    The interaction of bacterial pathogens with mammalian hosts leads to a variety of physiological responses of the interacting partners aimed at an adaptation to the new situation. These responses include multiple metabolic changes in the affected host cells which are most obvious when the pathogen replicates within host cells as in case of intracellular bacterial pathogens. While the pathogen tries to deprive nutrients from the host cell, the host cell in return takes various metabolic countermeasures against the nutrient theft. During this conflicting interaction, the pathogen triggers metabolic host cell responses by means of common cell envelope components and specific virulence-associated factors. These host reactions generally promote replication of the pathogen. There is growing evidence that pathogen-specific factors may interfere in different ways with the complex regulatory network that controls the carbon and nitrogen metabolism of mammalian cells. The host cell defense answers include general metabolic reactions, like the generation of oxygen- and/or nitrogen-reactive species, and more specific measures aimed to prevent access to essential nutrients for the respective pathogen. Accurate results on metabolic host cell responses are often hampered by the use of cancer cell lines that already exhibit various de-regulated reactions in the primary carbon metabolism. Hence, there is an urgent need for cellular models that more closely reflect the in vivo infection conditions. The exact knowledge of the metabolic host cell responses may provide new interesting concepts for antibacterial therapies. PMID:23847769

  9. Draft genome sequences for the obligate bacterial predators Bacteriovorax spp. of four phylogenetic clusters

    PubMed Central

    2015-01-01

    Bacteriovorax is the halophilic genus of the obligate bacterial predators, Bdellovibrio and like organisms. The predators are known for their unique biphasic life style in which they search for and attack their prey in the free living phase; penetrate, grow, multiply and lyse the prey in the intraperiplasmic phase. Bacteriovorax isolates representing four phylogenetic clusters were selected for genomic sequencing. Only one type strain genome has been published so far from the genus Bacteriovorax. We report the genomes from non-type strains isolated from aquatic environments. Here we describe and compare the genomic features of the four strains, together with the classification and annotation. PMID:26203326

  10. Innovative approach for transcriptomic analysis of obligate intracellular pathogen: selective capture of transcribed sequences of Ehrlichia ruminantium

    PubMed Central

    2009-01-01

    Background Whole genome transcriptomic analysis is a powerful approach to elucidate the molecular mechanisms controlling the pathogenesis of obligate intracellular bacteria. However, the major hurdle resides in the low quantity of prokaryotic mRNAs extracted from host cells. Our model Ehrlichia ruminantium (ER), the causative agent of heartwater, is transmitted by tick Amblyomma variegatum. This bacterium affects wild and domestic ruminants and is present in Sub-Saharan Africa and the Caribbean islands. Because of its strictly intracellular location, which constitutes a limitation for its extensive study, the molecular mechanisms involved in its pathogenicity are still poorly understood. Results We successfully adapted the SCOTS method (Selective Capture of Transcribed Sequences) on the model Rickettsiales ER to capture mRNAs. Southern Blots and RT-PCR revealed an enrichment of ER's cDNAs and a diminution of ribosomal contaminants after three rounds of capture. qRT-PCR and whole-genome ER microarrays hybridizations demonstrated that SCOTS method introduced only a limited bias on gene expression. Indeed, we confirmed the differential gene expression between poorly and highly expressed genes before and after SCOTS captures. The comparative gene expression obtained from ER microarrays data, on samples before and after SCOTS at 96 hpi was significantly correlated (R2 = 0.7). Moreover, SCOTS method is crucial for microarrays analysis of ER, especially for early time points post-infection. There was low detection of transcripts for untreated samples whereas 24% and 70.7% were revealed for SCOTS samples at 24 and 96 hpi respectively. Conclusions We conclude that this SCOTS method has a key importance for the transcriptomic analysis of ER and can be potentially used for other Rickettsiales. This study constitutes the first step for further gene expression analyses that will lead to a better understanding of both ER pathogenicity and the adaptation of obligate intracellular bacteria to their environment. PMID:20034374

  11. Genomic insights into an obligate epibiotic bacterial predator: Micavibrio aeruginosavorus ARL-13

    PubMed Central

    2011-01-01

    Background Although bacterial predators play important roles in the dynamics of natural microbial communities, little is known about the molecular mechanism of bacterial predation and the evolution of diverse predatory lifestyles. Results We determined the complete genome sequence of Micavibrio aeruginosavorus ARL-13, an obligate bacterial predator that feeds by "leeching" externally to its prey. Despite being an obligate predator depending on prey for replication, M. aeruginosavorus encodes almost all major metabolic pathways. However, our genome analysis suggests that there are multiple amino acids that it can neither make nor import directly from the environment, thus providing a simple explanation for its strict dependence on prey. Remarkably, despite apparent genome reduction, there is a massive expansion of genomic islands of foreign origin. At least nine genomic islands encode many genes that are likely important for Micavibrio-prey interaction such as hemolysin-related proteins. RNA-Seq analysis shows substantial transcriptome differences between the attack phase, when M. aeruginosavorus seeks its prey, and the attachment phase, when it feeds and multiplies. Housekeeping genes as well as genes involved in protein secretion were all dramatically up-regulated in the attachment phase. In contrast, genes involved in chemotaxis and flagellum biosynthesis were highly expressed in the attack phase but were shut down in the attachment phase. Our transcriptomic analysis identified additional genes likely important in Micavibrio predation, including porins, pilins and many hypothetical genes. Conclusions The findings from our phylogenomic and transcriptomic analyses shed new light on the biology and evolution of the epibiotic predatory lifestyle of M. aeruginosavorus. The analysis reported here and the availability of the complete genome sequence should catalyze future studies of this organism. PMID:21936919

  12. Motor-driven intracellular transport powers bacterial gliding motility.

    PubMed

    Sun, Mingzhai; Wartel, Morgane; Cascales, Eric; Shaevitz, Joshua W; Mignot, Tâm

    2011-05-01

    Protein-directed intracellular transport has not been observed in bacteria despite the existence of dynamic protein localization and a complex cytoskeleton. However, protein trafficking has clear potential uses for important cellular processes such as growth, development, chromosome segregation, and motility. Conflicting models have been proposed to explain Myxococcus xanthus motility on solid surfaces, some favoring secretion engines at the rear of cells and others evoking an unknown class of molecular motors distributed along the cell body. Through a combination of fluorescence imaging, force microscopy, and genetic manipulation, we show that membrane-bound cytoplasmic complexes consisting of motor and regulatory proteins are directionally transported down the axis of a cell at constant velocity. This intracellular motion is transmitted to the exterior of the cell and converted to traction forces on the substrate. Thus, this study demonstrates the existence of a conserved class of processive intracellular motors in bacteria and shows how these motors have been adapted to produce cell motility. PMID:21482768

  13. Cytosolic Access of Intracellular Bacterial Pathogens: The Shigella Paradigm.

    PubMed

    Mellouk, Nora; Enninga, Jost

    2016-01-01

    Shigella is a Gram-negative bacterial pathogen, which causes bacillary dysentery in humans. A crucial step of Shigella infection is its invasion of epithelial cells. Using a type III secretion system, Shigella injects several bacterial effectors ultimately leading to bacterial internalization within a vacuole. Then, Shigella escapes rapidly from the vacuole, it replicates within the cytosol and spreads from cell-to-cell. The molecular mechanism of vacuolar rupture used by Shigella has been studied in some detail during the recent years and new paradigms are emerging about the underlying molecular events. For decades, bacterial effector proteins were portrayed as main actors inducing vacuolar rupture. This includes the effector/translocators IpaB and IpaC. More recently, this has been challenged and an implication of the host cell in the process of vacuolar rupture has been put forward. This includes the bacterial subversion of host trafficking regulators, such as the Rab GTPase Rab11. The involvement of the host in determining bacterial vacuolar integrity has also been found for other bacterial pathogens, particularly for Salmonella. Here, we will discuss our current view of host factor and pathogen effector implications during Shigella vacuolar rupture and the steps leading to it. PMID:27092296

  14. Cytosolic Access of Intracellular Bacterial Pathogens: The Shigella Paradigm

    PubMed Central

    Mellouk, Nora; Enninga, Jost

    2016-01-01

    Shigella is a Gram-negative bacterial pathogen, which causes bacillary dysentery in humans. A crucial step of Shigella infection is its invasion of epithelial cells. Using a type III secretion system, Shigella injects several bacterial effectors ultimately leading to bacterial internalization within a vacuole. Then, Shigella escapes rapidly from the vacuole, it replicates within the cytosol and spreads from cell-to-cell. The molecular mechanism of vacuolar rupture used by Shigella has been studied in some detail during the recent years and new paradigms are emerging about the underlying molecular events. For decades, bacterial effector proteins were portrayed as main actors inducing vacuolar rupture. This includes the effector/translocators IpaB and IpaC. More recently, this has been challenged and an implication of the host cell in the process of vacuolar rupture has been put forward. This includes the bacterial subversion of host trafficking regulators, such as the Rab GTPase Rab11. The involvement of the host in determining bacterial vacuolar integrity has also been found for other bacterial pathogens, particularly for Salmonella. Here, we will discuss our current view of host factor and pathogen effector implications during Shigella vacuolar rupture and the steps leading to it. PMID:27092296

  15. Immunological mechanisms contributing to the double burden of diabetes and intracellular bacterial infections

    PubMed Central

    Hodgson, Kelly; Morris, Jodie; Bridson, Tahnee; Govan, Brenda; Rush, Catherine; Ketheesan, Natkunam

    2015-01-01

    Diabetes has been recognized as an important risk factor for a variety of intracellular bacterial infections, but research into the dysregulated immune mechanisms contributing to the impaired host–pathogen interactions is in its infancy. Diabetes is characterized by a chronic state of low-grade inflammation due to activation of pro-inflammatory mediators and increased formation of advanced glycation end products. Increased oxidative stress also exacerbates the chronic inflammatory processes observed in diabetes. The reduced phagocytic and antibacterial activity of neutrophils and macrophages provides an intracellular niche for the pathogen to replicate. Phagocytic and antibacterial dysfunction may be mediated directly through altered glucose metabolism and oxidative stress. Furthermore, impaired activation of natural killer cells contributes to decreased levels of interferon-γ, required for promoting macrophage antibacterial mechanisms. Together with impaired dendritic cell function, this impedes timely activation of adaptive immune responses. Increased intracellular oxidation of antigen-presenting cells in individuals with diabetes alters the cytokine profile generated and the subsequent balance of T-cell immunity. The establishment of acute intracellular bacterial infections in the diabetic host is associated with impaired T-cell-mediated immune responses. Concomitant to the greater intracellular bacterial burden and potential cumulative effect of chronic inflammatory processes, late hyper-inflammatory cytokine responses are often observed in individuals with diabetes, contributing to systemic pathology. The convergence of intracellular bacterial infections and diabetes poses new challenges for immunologists, providing the impetus for multidisciplinary research. PMID:25262977

  16. Human Female Genital Tract Infection by the Obligate Intracellular Bacterium Chlamydia trachomatis Elicits Robust Type 2 Immunity

    PubMed Central

    Vicetti Miguel, Rodolfo D.; Harvey, Stephen A. K.; LaFramboise, William A.; Reighard, Seth D.; Matthews, Dean B.; Cherpes, Thomas L.

    2013-01-01

    While Chlamydia trachomatis infections are frequently asymptomatic, mechanisms that regulate host response to this intracellular Gram-negative bacterium remain undefined. This investigation thus used peripheral blood mononuclear cells and endometrial tissue from women with or without Chlamydia genital tract infection to better define this response. Initial genome-wide microarray analysis revealed highly elevated expression of matrix metalloproteinase 10 and other molecules characteristic of Type 2 immunity (e.g., fibrosis and wound repair) in Chlamydia-infected tissue. This result was corroborated in flow cytometry and immunohistochemistry studies that showed extant upper genital tract Chlamydia infection was associated with increased co-expression of CD200 receptor and CD206 (markers of alternative macrophage activation) by endometrial macrophages as well as increased expression of GATA-3 (the transcription factor regulating TH2 differentiation) by endometrial CD4+ T cells. Also among women with genital tract Chlamydia infection, peripheral CD3+ CD4+ and CD3+ CD4- cells that proliferated in response to ex vivo stimulation with inactivated chlamydial antigen secreted significantly more interleukin (IL)-4 than tumor necrosis factor, interferon-γ, or IL-17; findings that repeated in T cells isolated from these same women 1 and 4 months after infection had been eradicated. Our results thus newly reveal that genital infection by an obligate intracellular bacterium induces polarization towards Type 2 immunity, including Chlamydia-specific TH2 development. Based on these findings, we now speculate that Type 2 immunity was selected by evolution as the host response to C. trachomatis in the human female genital tract to control infection and minimize immunopathological damage to vital reproductive structures. PMID:23555586

  17. Human female genital tract infection by the obligate intracellular bacterium Chlamydia trachomatis elicits robust Type 2 immunity.

    PubMed

    Vicetti Miguel, Rodolfo D; Harvey, Stephen A K; LaFramboise, William A; Reighard, Seth D; Matthews, Dean B; Cherpes, Thomas L

    2013-01-01

    While Chlamydia trachomatis infections are frequently asymptomatic, mechanisms that regulate host response to this intracellular Gram-negative bacterium remain undefined. This investigation thus used peripheral blood mononuclear cells and endometrial tissue from women with or without Chlamydia genital tract infection to better define this response. Initial genome-wide microarray analysis revealed highly elevated expression of matrix metalloproteinase 10 and other molecules characteristic of Type 2 immunity (e.g., fibrosis and wound repair) in Chlamydia-infected tissue. This result was corroborated in flow cytometry and immunohistochemistry studies that showed extant upper genital tract Chlamydia infection was associated with increased co-expression of CD200 receptor and CD206 (markers of alternative macrophage activation) by endometrial macrophages as well as increased expression of GATA-3 (the transcription factor regulating TH2 differentiation) by endometrial CD4(+) T cells. Also among women with genital tract Chlamydia infection, peripheral CD3(+) CD4(+) and CD3(+) CD4(-) cells that proliferated in response to ex vivo stimulation with inactivated chlamydial antigen secreted significantly more interleukin (IL)-4 than tumor necrosis factor, interferon-γ, or IL-17; findings that repeated in T cells isolated from these same women 1 and 4 months after infection had been eradicated. Our results thus newly reveal that genital infection by an obligate intracellular bacterium induces polarization towards Type 2 immunity, including Chlamydia-specific TH2 development. Based on these findings, we now speculate that Type 2 immunity was selected by evolution as the host response to C. trachomatis in the human female genital tract to control infection and minimize immunopathological damage to vital reproductive structures. PMID:23555586

  18. Biochemical evidence for the existence of thymidylate synthase in the obligate intracellular parasite Chlamydia trachomatis.

    PubMed Central

    Fan, H Z; McClarty, G; Brunham, R C

    1991-01-01

    Since eucaryotic cell-derived thymidine or thymidine nucleotides are not incorporated into Chlamydia trachomatis DNA, we hypothesized that C. trachomatis must obtain dTTP for DNA synthesis by converting dUMP to dTMP. In most cells, this reaction is catalyzed by thymidylate synthase (TS) and requires 5,10-methylenetetrahydrofolate as a cofactor. We used C. trachomatis serovar L2 and a mutant CHO K1 cell line with a genetic deficiency in folate metabolism as a host for chlamydial growth. This cell line lacks a functional dihydrofolate reductase (DHFR) gene and, as a result, is unable to carry out de novo synthesis of dTTP. C. trachomatis inclusions form normally when DHFR- cells are starved for thymidine 24 h prior to and during the course of infection. When [6-3H]uridine is used as a precursor to label C. trachomatis-infected CHO DHFR- cells, radiolabel is readily incorporated into chlamydia-specific DNA. When DNA from [6-3H]uridine-labelled infected cultures is acid hydrolyzed and subjected to high-performance liquid chromatography analysis, radiolabel is detected in thymine and cytosine nucleobases. By using the DHFR- cell line as a host and [5-3H]uridine as a precursor, we could monitor intracellular C. trachomatis TS activity simply by following the formation of tritiated water. There is a good correlation between in situ TS activity and DNA synthesis activity during the chlamydial growth cycle. In addition, both C. trachomatis-specific DNA synthesis and 3H2O release are inhibited by exogenously added 5-fluorouridine but not by 5-fluorodeoxyuridine. Finally, we demonstrated in vitro TS activity in crude extracts prepared from highly purified C. trachomatis reticulate bodies. The activity is dependent on the presence of methylenetetrahydrofolic acid and can be inhibited with 5-fluoro-dUMP. Taken together, these results indicate that C. trachomatis contains a TS for the synthesis of dTMP. PMID:1938873

  19. Evolution to a chronic disease niche correlates with increased sensitivity to tryptophan availability for the obligate intracellular bacterium Chlamydia pneumoniae.

    PubMed

    Huston, Wilhelmina M; Barker, Christopher J; Chacko, Anu; Timms, Peter

    2014-06-01

    The chlamydiae are obligate intracellular parasites that have evolved specific interactions with their various hosts and host cell types to ensure their successful survival and consequential pathogenesis. The species Chlamydia pneumoniae is ubiquitous, with serological studies showing that most humans are infected at some stage in their lifetime. While most human infections are asymptomatic, C. pneumoniae can cause more-severe respiratory disease and pneumonia and has been linked to chronic diseases such as asthma, atherosclerosis, and even Alzheimer's disease. The widely dispersed animal-adapted C. pneumoniae strains cause an equally wide range of diseases in their hosts. It is emerging that the ability of C. pneumoniae to survive inside its target cells, including evasion of the host's immune attack mechanisms, is linked to the acquisition of key metabolites. Tryptophan and arginine are key checkpoint compounds in this host-parasite battle. Interestingly, the animal strains of C. pneumoniae have a slightly larger genome, enabling them to cope better with metabolite restrictions. It therefore appears that as the evolutionarily more ancient animal strains have evolved to infect humans, they have selectively become more "susceptible" to the levels of key metabolites, such as tryptophan. While this might initially appear to be a weakness, it allows these human C. pneumoniae strains to exquisitely sense host immune attack and respond by rapidly reverting to a persistent phase. During persistence, they reduce their metabolic levels, halting progression of their developmental cycle, waiting until the hostile external conditions have passed before they reemerge. PMID:24682324

  20. The Genome of the Obligately Intracellular Bacterium Ehrlichia canis Reveals Themes of Complex Membrane Structure and Immune Evasion Strategies

    SciTech Connect

    Mavromatis, K; Doyle, C Kuyler; Lykidis, A; Ivanova, N; Francino, M P; Chain, Patrick S; Shin, M; Malfatti, Stephanie; Larimer, Frank W; Copeland, A; Detter, J C; Land, Miriam L; Richardson, P M; Yu, X J; Walker, D H; McBride, J W; Kyripides, N C

    2006-01-01

    Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, {alpha}-proteobacterium, is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, 17 putative pseudogenes, and a substantial proportion of noncoding sequence (27%). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences and a unique serine-threonine bias associated with the potential for O glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein families associated with immune evasion were identified, one of which contains poly(G-C) tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Genes associated with pathogen-host interactions were identified, including a small group encoding proteins (n = 12) with tandem repeats and another group encoding proteins with eukaryote-like ankyrin domains (n = 7).

  1. Evolution to a Chronic Disease Niche Correlates with Increased Sensitivity to Tryptophan Availability for the Obligate Intracellular Bacterium Chlamydia pneumoniae

    PubMed Central

    Huston, Wilhelmina M.; Barker, Christopher J.; Chacko, Anu

    2014-01-01

    The chlamydiae are obligate intracellular parasites that have evolved specific interactions with their various hosts and host cell types to ensure their successful survival and consequential pathogenesis. The species Chlamydia pneumoniae is ubiquitous, with serological studies showing that most humans are infected at some stage in their lifetime. While most human infections are asymptomatic, C. pneumoniae can cause more-severe respiratory disease and pneumonia and has been linked to chronic diseases such as asthma, atherosclerosis, and even Alzheimer's disease. The widely dispersed animal-adapted C. pneumoniae strains cause an equally wide range of diseases in their hosts. It is emerging that the ability of C. pneumoniae to survive inside its target cells, including evasion of the host's immune attack mechanisms, is linked to the acquisition of key metabolites. Tryptophan and arginine are key checkpoint compounds in this host-parasite battle. Interestingly, the animal strains of C. pneumoniae have a slightly larger genome, enabling them to cope better with metabolite restrictions. It therefore appears that as the evolutionarily more ancient animal strains have evolved to infect humans, they have selectively become more “susceptible” to the levels of key metabolites, such as tryptophan. While this might initially appear to be a weakness, it allows these human C. pneumoniae strains to exquisitely sense host immune attack and respond by rapidly reverting to a persistent phase. During persistence, they reduce their metabolic levels, halting progression of their developmental cycle, waiting until the hostile external conditions have passed before they reemerge. PMID:24682324

  2. Intracellular Bacterial Communities: A Potential Etiology for Chronic Lower Urinary Tract Symptoms

    PubMed Central

    Scott, Victoria C. S.; Haake, David A.; Churchill, Bernard M.; Justice, Sheryl S.; Kim, Ja-Hong

    2015-01-01

    Patients with persistent lower urinary tract symptoms and negative urine cultures are often difficult to treat. Infection may go undetected in these patients because the concentrations of bacteria in their urine are beneath the threshold of standard urine culture techniques. Empiric treatment may result in temporary relief, followed by recurrent symptoms. Occult and recurrent urinary tract infection may be due to both invasion of the bladder wall by uropathogenic Escherichia coli and the formation of biofilm-like intracellular bacterial communities. This review examines emerging evidence for a role of intracellular bacterial communities in human infection. PMID:26189137

  3. Host-Directed Antimicrobial Drugs with Broad-Spectrum Efficacy against Intracellular Bacterial Pathogens

    PubMed Central

    Czyż, Daniel M.; Potluri, Lakshmi-Prasad; Jain-Gupta, Neeta; Riley, Sean P.; Martinez, Juan J.; Steck, Theodore L.; Crosson, Sean; Gabay, Joëlle E.

    2014-01-01

    ABSTRACT We sought a new approach to treating infections by intracellular bacteria, namely, by altering host cell functions that support their growth. We screened a library of 640 Food and Drug Administration (FDA)-approved compounds for agents that render THP-1 cells resistant to infection by four intracellular pathogens. We identified numerous drugs that are not antibiotics but were highly effective in inhibiting intracellular bacterial growth with limited toxicity to host cells. These compounds are likely to target three kinds of host functions: (i) G protein-coupled receptors, (ii) intracellular calcium signals, and (iii) membrane cholesterol distribution. The compounds that targeted G protein receptor signaling and calcium fluxes broadly inhibited Coxiella burnetii, Legionella pneumophila, Brucella abortus, and Rickettsia conorii, while those directed against cholesterol traffic strongly attenuated the intracellular growth of C. burnetii and L. pneumophila. These pathways probably support intracellular pathogen growth so that drugs that perturb them may be therapeutic candidates. Combining host- and pathogen-directed treatments is a strategy to decrease the emergence of drug-resistant intracellular bacterial pathogens. PMID:25073644

  4. Directed antigen delivery as a vaccine strategy for an intracellular bacterial pathogen

    NASA Astrophysics Data System (ADS)

    Bouwer, H. G. Archie; Alberti-Segui, Christine; Montfort, Megan J.; Berkowitz, Nathan D.; Higgins, Darren E.

    2006-03-01

    We have developed a vaccine strategy for generating an attenuated strain of an intracellular bacterial pathogen that, after uptake by professional antigen-presenting cells, does not replicate intracellularly and is readily killed. However, after degradation of the vaccine strain within the phagolysosome, target antigens are released into the cytosol for endogenous processing and presentation for stimulation of CD8+ effector T cells. Applying this strategy to the model intracellular pathogen Listeria monocytogenes, we show that an intracellular replication-deficient vaccine strain is cleared rapidly in normal and immunocompromised animals, yet antigen-specific CD8+ effector T cells are stimulated after immunization. Furthermore, animals immunized with the intracellular replication-deficient vaccine strain are resistant to lethal challenge with a virulent WT strain of L. monocytogenes. These studies suggest a general strategy for developing safe and effective, attenuated intracellular replication-deficient vaccine strains for stimulation of protective immune responses against intracellular bacterial pathogens. CD8+ T cell | replication-deficient | Listeria monocytogenes

  5. Microfluidic pretreatment of bacterial cells for analysis of intracellular contents

    NASA Astrophysics Data System (ADS)

    Wang, Hsiang-Yu; Lu, Chang; Banada, Padmapriya P.; Jagadeesan, Balamurugan; Bhunia, Arun K.

    2005-11-01

    Electrical lysis of biological cells on a microfluidic platform has been raising a lot of interests due to its applications in rapid recovering intracellular contents without introducing lytic agents. In this study, we demonstrated a simple microfluidic device which lysed green fluorescent protein (GFP) expressing E. coli cells under continuous DC voltage while cells flowed through. The cell lysis only happened in a defined section of a microfluidic channel due to the local field amplification by geometric modification. The geometric modification also effectively decreased the required voltage for lysis by several folds. We found that a local field strength of 1500V/cm was required for lysis of nearly 100% of E. coli cells. This lysis field strength was considerably lower than the value reported in the literature, possibly due to the longer duration of the field. The lysis was witnessed by plate count and fluorescence spectroscopy. The devices were fabricated using low-cost soft lithography with channel widths considerably larger than the cell size to avoid clogging and ensure stable performance. Our tool will be ideal for high throughput processing of a large number of cells. Furthermore, the application of continuous DC field makes it straightforward to couple our cell lysis device with on-chip electrophoresis to realize the integration of cell pretreatment and chemical analysis. In principle, the same approach can also be applied for the lysis of mammalian cells and for the electroporation and transfection.

  6. Infected dendritic cells facilitate systemic dissemination and transplacental passage of the obligate intracellular parasite Neospora caninum in mice.

    PubMed

    Collantes-Fernandez, Esther; Arrighi, Romanico B G; Alvarez-García, Gema; Weidner, Jessica M; Regidor-Cerrillo, Javier; Boothroyd, John C; Ortega-Mora, Luis M; Barragan, Antonio

    2012-01-01

    The obligate intracellular parasite Neospora caninum disseminates across the placenta and the blood-brain barrier, to reach sites where it causes severe pathology or establishes chronic persistent infections. The mechanisms used by N. caninum to breach restrictive biological barriers remain elusive. To examine the cellular basis of these processes, migration of different N. caninum isolates (Nc-1, Nc-Liverpool, Nc-SweB1 and the Spanish isolates: Nc-Spain 3H, Nc-Spain 4H, Nc-Spain 6, Nc-Spain 7 and Nc-Spain 9) was studied in an in vitro model based on a placental trophoblast-derived BeWo cell line. Here, we describe that infection of dendritic cells (DC) by N. caninum tachyzoites potentiated translocation of parasites across polarized cellular monolayers. In addition, powered by the parasite's own gliding motility, extracellular N. caninum tachyzoites were able to transmigrate across cellular monolayers. Altogether, the presented data provides evidence of two putative complementary pathways utilized by N. caninum, in an isolate-specific fashion, for passage of restrictive cellular barriers. Interestingly, adoptive transfer of tachyzoite-infected DC in mice resulted in increased parasitic loads in various organs, e.g. the central nervous system, compared to infections with free parasites. Inoculation of pregnant mice with infected DC resulted in an accentuated vertical transmission to the offspring with increased parasitic loads and neonatal mortality. These findings reveal that N. caninum exploits the natural cell trafficking pathways in the host to cross cellular barriers and disseminate to deep tissues. The findings are indicative of conserved dissemination strategies among coccidian apicomplexan parasites. PMID:22403627

  7. Infected Dendritic Cells Facilitate Systemic Dissemination and Transplacental Passage of the Obligate Intracellular Parasite Neospora caninum in Mice

    PubMed Central

    Collantes-Fernandez, Esther; Arrighi, Romanico B. G.; Álvarez-García, Gema; Weidner, Jessica M.; Regidor-Cerrillo, Javier; Boothroyd, John C.; Ortega-Mora, Luis M.; Barragan, Antonio

    2012-01-01

    The obligate intracellular parasite Neospora caninum disseminates across the placenta and the blood-brain barrier, to reach sites where it causes severe pathology or establishes chronic persistent infections. The mechanisms used by N. caninum to breach restrictive biological barriers remain elusive. To examine the cellular basis of these processes, migration of different N. caninum isolates (Nc-1, Nc-Liverpool, Nc-SweB1 and the Spanish isolates: Nc-Spain 3H, Nc-Spain 4H, Nc-Spain 6, Nc-Spain 7 and Nc-Spain 9) was studied in an in vitro model based on a placental trophoblast-derived BeWo cell line. Here, we describe that infection of dendritic cells (DC) by N. caninum tachyzoites potentiated translocation of parasites across polarized cellular monolayers. In addition, powered by the parasite's own gliding motility, extracellular N. caninum tachyzoites were able to transmigrate across cellular monolayers. Altogether, the presented data provides evidence of two putative complementary pathways utilized by N. caninum, in an isolate-specific fashion, for passage of restrictive cellular barriers. Interestingly, adoptive transfer of tachyzoite-infected DC in mice resulted in increased parasitic loads in various organs, e.g. the central nervous system, compared to infections with free parasites. Inoculation of pregnant mice with infected DC resulted in an accentuated vertical transmission to the offspring with increased parasitic loads and neonatal mortality. These findings reveal that N. caninum exploits the natural cell trafficking pathways in the host to cross cellular barriers and disseminate to deep tissues. The findings are indicative of conserved dissemination strategies among coccidian apicomplexan parasites. PMID:22403627

  8. Bacterial two hybrid: a versatile one-step intracellular selection method.

    PubMed

    Pellis, Mireille; Muyldermans, Serge; Vincke, Cécile

    2012-01-01

    Many antibody fragments, selected ex vivo by phage display, fail to form functional antigen-binding entities when expressed and used intracellularly (i.e., as intrabodies) because the interior of the cell poses significant challenges on the folding of antibodies. Such dropout can be avoided by employing intracellular selection methods like yeast or bacterial two hybrid systems. These involve four facile steps: construction of plasmids, transformation of microbial cells, intracellular expression of fusion proteins, and selection for reporter activity. Using E. coli as host instead of yeast offers the advantages of a faster growth and a higher transformation efficiency allowing to screen larger repertoires. This chapter describes the protocol, optimized to identify antigen-specific single domain antibodies (sdAbs), by bacterial two hybrid selection. PMID:22886250

  9. An efficient system for intracellular delivery of beta-lactam antibiotics to overcome bacterial resistance

    PubMed Central

    Abed, Nadia; Saïd-Hassane, Fatouma; Zouhiri, Fatima; Mougin, Julie; Nicolas, Valérie; Desmaële, Didier; Gref, Ruxandra; Couvreur, Patrick

    2015-01-01

    The “Golden era” of antibiotics is definitely an old story and this is especially true for intracellular bacterial infections. The poor intracellular bioavailability of antibiotics reduces the efficency of many treatments and thereby promotes resistances. Therefore, the development of nanodevices coupled with antibiotics that are capable of targeting and releasing the drug into the infected-cells appears to be a promising solution to circumvent these complications. Here, we took advantage of two natural terpenes (farnesyl and geranyl) to design nanodevices for an efficient intracellular delivery of penicillin G. The covalent linkage between the terpene moieties and the antibiotic leads to formation of prodrugs that self-assemble to form nanoparticles with a high drug payload between 55–63%. Futhermore, the addition of an environmentally-sensitive bond between the antibiotic and the terpene led to an efficient antibacterial activity against the intracellular pathogen Staphylococcus aureus with reduced intracellular replication of about 99.9% compared to untreated infected cells. Using HPLC analysis, we demonstrated and quantified the intracellular release of PenG when this sensitive-bond (SB) was present on the prodrug, showing the success of this technology to deliver antibiotics directly into cells. PMID:26311631

  10. Search for MicroRNAs Expressed by Intracellular Bacterial Pathogens in Infected Mammalian Cells

    PubMed Central

    Furuse, Yuki; Finethy, Ryan; Saka, Hector A.; Xet-Mull, Ana M.; Sisk, Dana M.; Smith, Kristen L. Jurcic; Lee, Sunhee; Coers, Jörn; Valdivia, Raphael H.; Tobin, David M.; Cullen, Bryan R.

    2014-01-01

    MicroRNAs are expressed by all multicellular organisms and play a critical role as post-transcriptional regulators of gene expression. Moreover, different microRNA species are known to influence the progression of a range of different diseases, including cancer and microbial infections. A number of different human viruses also encode microRNAs that can attenuate cellular innate immune responses and promote viral replication, and a fungal pathogen that infects plants has recently been shown to express microRNAs in infected cells that repress host cell immune responses and promote fungal pathogenesis. Here, we have used deep sequencing of total expressed small RNAs, as well as small RNAs associated with the cellular RNA-induced silencing complex RISC, to search for microRNAs that are potentially expressed by intracellular bacterial pathogens and translocated into infected animal cells. In the case of Legionella and Chlamydia and the two mycobacterial species M. smegmatis and M. tuberculosis, we failed to detect any bacterial small RNAs that had the characteristics expected for authentic microRNAs, although large numbers of small RNAs of bacterial origin could be recovered. However, a third mycobacterial species, M. marinum, did express an ∼23-nt small RNA that was bound by RISC and derived from an RNA stem-loop with the characteristics expected for a pre-microRNA. While intracellular expression of this candidate bacterial microRNA was too low to effectively repress target mRNA species in infected cultured cells in vitro, artificial overexpression of this potential bacterial pre-microRNA did result in the efficient repression of a target mRNA. This bacterial small RNA therefore represents the first candidate microRNA of bacterial origin. PMID:25184567

  11. Permanent residents or temporary lodgers: characterizing intracellular bacterial communities in the siphonous green alga Bryopsis

    PubMed Central

    Hollants, Joke; Leliaert, Frederik; Verbruggen, Heroen; Willems, Anne; De Clerck, Olivier

    2013-01-01

    The ecological success of giant celled, siphonous green algae in coastal habitats has repeatedly been linked to endophytic bacteria living within the cytoplasm of the hosts. Yet, very little is known about the relative importance of evolutionary and ecological factors controlling the intracellular bacterial flora of these seaweeds. Using the marine alga Bryopsis (Bryopsidales, Chlorophyta) as a model, we explore the diversity of the intracellular bacterial communities and investigate whether their composition is controlled by ecological and biogeographic factors rather than the evolutionary history of the host. Using a combination of 16S rDNA clone libraries and denaturing gradient gel electrophoresis analyses, we show that Bryopsis harbours a mixture of relatively few but phylogenetically diverse bacterial species. Variation partitioning analyses show a strong impact of local environmental factors on the presence of Rickettsia and Mycoplasma in their association with Bryopsis. The presence of Flavobacteriaceae and Bacteroidetes, on the other hand, reflects a predominant imprint of host evolutionary history, suggesting that these bacteria are more specialized in their association. The results highlight the importance of interpreting the presence of individual bacterial phylotypes in the light of ecological and evolutionary principles such as phylogenetic niche conservatism to understand complex endobiotic communities and the parameters shaping them. PMID:23303543

  12. RIG-I Detects mRNA of Intracellular Salmonella enterica Serovar Typhimurium during Bacterial Infection

    PubMed Central

    Schmolke, Mirco; Patel, Jenish R.; de Castro, Elisa; Snchez-Aparicio, Maria T.; Uccellini, Melissa B.; Miller, Jennifer C.; Manicassamy, Balaji; Satoh, Takashi; Kawai, Taro; Akira, Shizuo; Merad, Miriam; Garca-Sastre, Adolfo

    2014-01-01

    ABSTRACT The cytoplasmic helicase RIG-I is an established sensor for viral 5?-triphosphorylated RNA species. Recently, RIG-I was also implicated in the detection of intracellular bacteria. However, little is known about the host cell specificity of this process and the bacterial pathogen-associated molecular pattern (PAMP) that activates RIG-I. Here we show that RNA of Salmonella enterica serovar Typhimurium activates production of beta interferon in a RIG-I-dependent fashion only in nonphagocytic cells. In phagocytic cells, RIG-I is obsolete for detection of Salmonella infection. We further demonstrate that Salmonella mRNA reaches the cytoplasm during infection and is thus accessible for RIG-I. The results from next-generation sequencing analysis of RIG-I-associated RNA suggest that coding bacterial mRNAs represent the activating PAMP. PMID:24692634

  13. Cellular uptake and intracellular fate of protein releasing bacterial amyloids in mammalian cells.

    PubMed

    Seras-Franzoso, Joaquin; Sánchez-Chardi, Alejandro; Garcia-Fruitós, Elena; Vázquez, Esther; Villaverde, Antonio

    2016-04-14

    Bacterial Inclusion Bodies (IBs) are amyloidal protein deposits that functionally mimic secretory granules from the endocrine system. When formed by therapeutically relevant proteins, they complement missing intracellular activities in jeopardized cell cultures, offering an intriguing platform for protein drug delivery in substitutive therapies. Despite the therapeutic potential of IBs, their capability to interact with eukaryotic cells, cross the cell membrane and release their functional building blocks into the cytosolic space remains essentially unexplored. We have systematically dissected the process by which bacterial amyloids interact with mammalian cells. An early and tight cell membrane anchorage of IBs is followed by cellular uptake of single or grouped IBs of variable sizes by macropinocytosis. Although an important fraction of the penetrating particles is led to lysosomal degradation, biologically significant amounts of protein are released into the cytosol. In addition, our data suggest the involvement of the bacterial cell folding modulator DnaK in the release of functional proteins from these amyloidal reservoirs. The mechanisms supporting the internalization of disintegrable protein nanoparticles revealed here offer clues to implement novel approaches for protein drug delivery based on controlled protein packaging as bacterial IBs. PMID:26956912

  14. Trogocytosis-associated cell to cell spread of intracellular bacterial pathogens

    PubMed Central

    Steele, Shaun; Radlinski, Lauren; Taft-Benz, Sharon; Brunton, Jason; Kawula, Thomas H

    2016-01-01

    Macrophages are myeloid-derived phagocytic cells and one of the first immune cell types to respond to microbial infections. However, a number of bacterial pathogens are resistant to the antimicrobial activities of macrophages and can grow within these cells. Macrophages have other immune surveillance roles including the acquisition of cytosolic components from multiple types of cells. We hypothesized that intracellular pathogens that can replicate within macrophages could also exploit cytosolic transfer to facilitate bacterial spread. We found that viable Francisella tularensis, as well as Salmonella enterica bacteria transferred from infected cells to uninfected macrophages along with other cytosolic material through a transient, contact dependent mechanism. Bacterial transfer occurred when the host cells exchanged plasma membrane proteins and cytosol via a trogocytosis related process leaving both donor and recipient cells intact and viable. Trogocytosis was strongly associated with infection in mice, suggesting that direct bacterial transfer occurs by this process in vivo. DOI: http://dx.doi.org/10.7554/eLife.10625.001 PMID:26802627

  15. Genomic revelations of a mutualism: the pea aphid and its obligate bacterial symbiont.

    PubMed

    Shigenobu, Shuji; Wilson, Alex C C

    2011-04-01

    The symbiosis of the pea aphid Acyrthosphion pisum with the bacterium Buchnera aphidicola APS represents the best-studied insect obligate symbiosis. Here we present a refined picture of this symbiosis by linking pre-genomic observations to new genomic data that includes the complete genomes of the eukaryotic and prokaryotic symbiotic partners. In doing so, we address four issues central to understanding the patterns and processes operating at the A. pisum/Buchnera APS interface. These four issues include: (1) lateral gene transfer, (2) host immunity, (3) symbiotic metabolism, and (4) regulation. PMID:21390549

  16. An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent.

    PubMed

    Beatty, J Thomas; Overmann, Jörg; Lince, Michael T; Manske, Ann K; Lang, Andrew S; Blankenship, Robert E; Van Dover, Cindy L; Martinson, Tracey A; Plumley, F Gerald

    2005-06-28

    The abundance of life on Earth is almost entirely due to biological photosynthesis, which depends on light energy. The source of light in natural habitats has heretofore been thought to be the sun, thus restricting photosynthesis to solar photic environments on the surface of the Earth. If photosynthesis could take place in geothermally illuminated environments, it would increase the diversity of photosynthetic habitats both on Earth and on other worlds that have been proposed to possibly harbor life. Green sulfur bacteria are anaerobes that require light for growth by the oxidation of sulfur compounds to reduce CO2 to organic carbon, and are capable of photosynthetic growth at extremely low light intensities. We describe the isolation and cultivation of a previously unknown green sulfur bacterial species from a deep-sea hydrothermal vent, where the only source of light is geothermal radiation that includes wavelengths absorbed by photosynthetic pigments of this organism. PMID:15967984

  17. Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii.

    PubMed

    Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

    2016-01-01

    Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure the parasite survival. The parasite can counteract genetic ablation of its glucose transporter by increasing the flux of glutamine-derived carbon through the tricarboxylic acid cycle and by concurrently activating gluconeogenesis, which guarantee a continued biogenesis of ATP and biomass for host-cell invasion and parasite replication, respectively. In accord, a pharmacological inhibition of glutaminolysis or oxidative phosphorylation arrests the lytic cycle of the glycolysis-deficient mutant, which is primarily a consequence of impaired invasion due to depletion of ATP. Unexpectedly, however, intracellular parasites continue to proliferate, albeit slower, notwithstanding a simultaneous deprivation of glucose and glutamine. A growth defect in the glycolysis-impaired mutant is caused by a compromised synthesis of lipids, which cannot be counterbalanced by glutamine but can be restored by acetate. Consistently, supplementation of parasite cultures with exogenous acetate can amend the lytic cycle of the glucose transport mutant. Such plasticity in the parasite's carbon flux enables a growth-and-survival trade-off in assorted nutrient milieus, which may underlie the promiscuous survival of T. gondii tachyzoites in diverse host cells. Our results also indicate a convergence of parasite metabolism with cancer cells. PMID:26518878

  18. Two apextrin-like proteins mediate extracellular and intracellular bacterial recognition in amphioxus

    PubMed Central

    Huang, Guangrui; Huang, Shengfeng; Yan, Xinyu; Yang, Ping; Li, Jun; Xu, Weiya; Zhang, Lingling; Wang, Ruihua; Yu, Yingcai; Yuan, Shaochun; Chen, Shangwu; Luo, Guangbin; Xu, Anlong

    2014-01-01

    Animals exploit different germ-line-encoded proteins with various domain structures to detect the signature molecules of pathogenic microbes. These molecules are known as pathogen-associated molecular patterns (PAMPs), and the host proteins that react with PAMPs are called pattern recognition proteins (PRPs). Here, we present a novel type of protein domain structure capable of binding to bacterial peptidoglycan (PGN) and the minimal PGN motif muramyl dipeptide (MDP). This domain is designated as apextrin C-terminal domain (ApeC), and its presence was confirmed in several invertebrate phyla and subphyla. Two apextrin-like proteins (ALP1 and ALP2) were identified in a basal chordate, the Japanese amphioxus Branchiostoma japonicum (bj). bjALP1 is a mucosal effector secreted into the gut lumen to agglutinate the Gram-positive bacterium Staphylococcus aureus via PGN binding. Neutralization of secreted bjALP1 by anti-bjALP1 monoclonal antibodies caused serious damage to the gut epithelium and rapid death of the animals after bacterial infection. bjALP2 is an intracellular PGN sensor that binds to TNF receptor-associated factor 6 (TRAF6) and prevents TRAF6 from self-ubiquitination and hence from NF-κB activation. MDP was found to compete with TRAF6 for bjALP2, which released TRAF6 to activate the NF-κB pathway. BjALP1 and bjALP2 therefore play distinct and complementary functions in amphioxus gut mucosal immunity. In conclusion, discovery of the ApeC domain and the functional analyses of amphioxus ALP1 and ALP2 allowed us to define a previously undocumented type of PRP that is represented across different animal phyla. PMID:25187559

  19. Hpt, a bacterial homolog of the microsomal glucose- 6-phosphate translocase, mediates rapid intracellular proliferation in Listeria

    PubMed Central

    Chico-Calero, Isabel; Suárez, Mónica; González-Zorn, Bruno; Scortti, Mariela; Slaghuis, Jörg; Goebel, Werner; Vázquez-Boland, José A.

    2002-01-01

    Efficient replication in vivo is essential for a microparasite to colonize its host and the understanding of the molecular mechanisms by which microbial pathogens grow within host tissues can lead to the discovery of novel therapies to treat infection. Here we present evidence that the foodborne bacterial pathogen Listeria monocytogenes, a facultative intracellular parasite, exploits hexose phosphates (HP) from the host cell as a source of carbon and energy to fuel fast intracellular growth. HP uptake is mediated by Hpt, a bacterial homolog of the mammalian translocase that transports glucose-6-phosphate from the cytosol into the endoplasmic reticulum in the final step of gluconeogenesis and glycogenolysis. Expression of the Hpt permease is tightly controlled by the central virulence regulator PrfA, which upon entry into host cells induces a set of virulence factors required for listerial intracellular parasitism. Loss of Hpt resulted in impaired listerial intracytosolic proliferation and attenuated virulence in mice. Hpt is the first virulence factor to be identified as specifically involved in the replication phase of a facultative intracellular pathogen. It is also a clear example of how adaptation to intracellular parasitism by microbial pathogens involves mimicry of physiological mechanisms of their eukaryotic host cells. PMID:11756655

  20. The complete genomic sequence of Mycoplasma penetrans, an intracellular bacterial pathogen in humans

    PubMed Central

    Sasaki, Yuko; Ishikawa, Jun; Yamashita, Atsushi; Oshima, Kenshiro; Kenri, Tsuyoshi; Furuya, Keiko; Yoshino, Chie; Horino, Atsuko; Shiba, Tadayoshi; Sasaki, Tsuguo; Hattori, Masahira

    2002-01-01

    The complete genomic sequence of an intracellular bacterial pathogen, Mycoplasma penetrans HF-2 strain, was determined. The HF-2 genome consists of a 1 358 633 bp single circular chromosome containing 1038 predicted coding sequences (CDSs), one set of rRNA genes and 30 tRNA genes. Among the 1038 CDSs, 264 predicted proteins are common to the Mycoplasmataceae sequenced thus far and 463 are M.penetrans specific. The genome contains the two-component system but lacks the essential cellular gene, uridine kinase. The relatively large genome of M.penetrans HF-2 among mycoplasma species may be accounted for by both its rich core proteome and the presence of a number of paralog families corresponding to 25.4% of all CDSs. The largest paralog family is the p35 family, which encodes surface lipoproteins including the major antigen, P35. A total of 44 genes for p35 and p35 homologs were identified and 30 of them form one large cluster in the chromosome. The genetic tree of p35 paralogs suggests the occurrence of dynamic chromosomal rearrangement in paralog formation during evolution. Thus, M.penetrans HF-2 may have acquired diverse repertoires of antigenic variation-related genes to allow its persistent infection in humans. PMID:12466555

  1. Characterization of an Obligate Intracellular Bacterium in the Midgut Epithelium of the Bulrush Bug Chilacis typhae (Heteroptera, Lygaeidae, Artheneinae)▿

    PubMed Central

    Kuechler, Stefan Martin; Dettner, Konrad; Kehl, Siegfried

    2011-01-01

    Many members of the suborder Heteroptera have symbiotic bacteria, which are usually found extracellularly in specific sacs or tubular outgrowths of the midgut or intracellularly in mycetomes. In this study, we describe the second molecular characterization of a symbiotic bacterium in a monophagous, seed-sucking stink bug of the family Lygaeidae (sensu stricto). Chilacis typhae possesses at the end of the first section of the midgut a structure which is composed of circularly arranged, strongly enlarged midgut epithelial cells. It is filled with an intracellular endosymbiont. This “mycetocytic belt” might represent an evolutionarily intermediate stage of the usual symbiotic structures found in stink bugs. Phylogenetic analysis based on the 16S rRNA and the groEL genes showed that the bacterium belongs to the Gammaproteobacteria, and it revealed a phylogenetic relationship with a secondary bacterial endosymbiont of Cimex lectularius and free-living plant pathogens such as Pectobacterium and Dickeya. The distribution and ultrastructure of the rod-shaped Chilacis endosymbiont were studied in adults and nymph stages using fluorescence in situ hybridization (FISH) and electron microscopy. The detection of symbionts at the anterior poles of developing eggs indicates that endosymbionts are transmitted vertically. A new genus and species name, “Candidatus Rohrkolberia cinguli,” is proposed for this newly characterized clade of symbiotic bacteria. PMID:21378044

  2. Proteomic Analyses of Intracellular Salmonella enterica Serovar Typhimurium Reveal Extensive Bacterial Adaptations to Infected Host Epithelial Cells

    PubMed Central

    Liu, Yanhua; Zhang, Qiufeng; Hu, Mo; Yu, Kaiwen; Fu, Jiaqi; Zhou, Fan

    2015-01-01

    Salmonella species can gain access into nonphagocytic cells, where the bacterium proliferates in a unique membrane-bounded compartment. In order to reveal bacterial adaptations to their intracellular niche, here we conducted the first comprehensive proteomic survey of Salmonella isolated from infected epithelial cells. Among ∼3,300 identified bacterial proteins, we found that about 100 proteins were significantly altered at the onset of Salmonella intracellular replication. In addition to substantially increased iron-uptake capacities, bacterial high-affinity manganese and zinc transporters were also upregulated, suggesting an overall limitation of metal ions in host epithelial cells. We also found that Salmonella induced multiple phosphate utilization pathways. Furthermore, our data suggested upregulation of the two-component PhoPQ system as well as of many downstream virulence factors under its regulation. Our survey also revealed that intracellular Salmonella has increased needs for certain amino acids and biotin. In contrast, Salmonella downregulated glycerol and maltose utilization as well as chemotaxis pathways. PMID:25939512

  3. TLR-Independent Type I Interferon Induction in Response to an Extracellular Bacterial Pathogen via Intracellular Recognition of Its DNA

    PubMed Central

    Charrel-Dennis, Marie; Latz, Eicke; Halmen, Kristen A.; Trieu-Cuot, Patrick; Fitzgerald, Katherine A.; Kasper, Dennis L.; Golenbock, Douglas T.

    2011-01-01

    SUMMARY Type I interferon (IFN) is an important host defense cytokine against intracellular pathogens, mainly viruses. In assessing IFN production in response to group B streptococcus (GBS), we find that IFN-? was produced by macrophages upon stimulation with both heat-killed and live GBS. Exposure of macrophages to heat-killed GBS activated a Toll-like receptor (TLR)-dependent pathway, whereas live GBS activated a TLR/NOD/RIG-like receptor (RLR)-independent pathway. This latter pathway required bacterial phagocytosis, proteolytic bacterial degradation, and phagolysosomal membrane destruction by GBS pore-forming toxins, leading to the release of bacterial DNA into the cytosol. GBS DNA in the cytosol induced IFN-? production via a pathway dependent on the activation of the serine-threonine kinase TBK1 and phosphorylation of the transcription factor IRF3. Thus, activation of IFN-?/-? production during infection with GBS, commonly considered an extracellular pathogen, appears to result from the interaction of GBS DNA with a putative intracellular DNA sensor or receptor. PMID:19064255

  4. A Rickettsia Genome Overrun by Mobile Genetic Elements Provides Insight into the Acquisition of Genes Characteristic of an Obligate Intracellular Lifestyle

    PubMed Central

    Joardar, Vinita; Williams, Kelly P.; Driscoll, Timothy; Hostetler, Jessica B.; Nordberg, Eric; Shukla, Maulik; Walenz, Brian; Hill, Catherine A.; Nene, Vishvanath M.; Azad, Abdu F.; Sobral, Bruno W.; Caler, Elisabet

    2012-01-01

    We present the draft genome for the Rickettsia endosymbiont of Ixodes scapularis (REIS), a symbiont of the deer tick vector of Lyme disease in North America. Among Rickettsia species (Alphaproteobacteria: Rickettsiales), REIS has the largest genome sequenced to date (>2 Mb) and contains 2,309 genes across the chromosome and four plasmids (pREIS1 to pREIS4). The most remarkable finding within the REIS genome is the extraordinary proliferation of mobile genetic elements (MGEs), which contributes to a limited synteny with other Rickettsia genomes. In particular, an integrative conjugative element named RAGE (for Rickettsiales amplified genetic element), previously identified in scrub typhus rickettsiae (Orientia tsutsugamushi) genomes, is present on both the REIS chromosome and plasmids. Unlike the pseudogene-laden RAGEs of O. tsutsugamushi, REIS encodes nine conserved RAGEs that include F-like type IV secretion systems similar to that of the tra genes encoded in the Rickettsia bellii and R. massiliae genomes. An unparalleled abundance of encoded transposases (>650) relative to genome size, together with the RAGEs and other MGEs, comprise ∼35% of the total genome, making REIS one of the most plastic and repetitive bacterial genomes sequenced to date. We present evidence that conserved rickettsial genes associated with an intracellular lifestyle were acquired via MGEs, especially the RAGE, through a continuum of genomic invasions. Robust phylogeny estimation suggests REIS is ancestral to the virulent spotted fever group of rickettsiae. As REIS is not known to invade vertebrate cells and has no known pathogenic effects on I. scapularis, its genome sequence provides insight on the origin of mechanisms of rickettsial pathogenicity. PMID:22056929

  5. Novel bioactive hydrophobic gentamicin carriers for the treatment of intracellular bacterial infections.

    PubMed

    Imbuluzqueta, Edurne; Elizondo, Elisa; Gamazo, Carlos; Moreno-Calvo, Evelyn; Veciana, Jaume; Ventosa, Nora; Blanco-Prieto, María J

    2011-04-01

    Gentamicin (GEN) is an aminoglycoside antibiotic with a potent antibacterial activity against a wide variety of bacteria. However, its poor cellular penetration limits its use in the treatment of infections caused by intracellular pathogens. One potential strategy to overcome this problem is the use of particulate carriers that can target the intracellular sites of infection. In this study GEN was ion-paired with the anionic AOT surfactant to obtain a hydrophobic complex (GEN-AOT) that was formulated as a particulated material either by the precipitation with a compressed antisolvent (PCA) method or by encapsulation into poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). The micronization of GEN-AOT by PCA yielded a particulated material with a higher surface area than the non-precipitated complex, while PLGA NPs within a size range of 250-330 nm and a sustained release of the drug over 70 days were obtained by preparing the NPs using the emulsion solvent evaporation method. For the first time, GEN encapsulation efficiency values of ∼100% were achieved for the different NP formulations with no signs of interaction between the drug and the polymer. Finally, in vitro studies against the intracellular bacteria Brucella melitensis, used as a model of intracellular pathogen, demonstrated that the bactericidal activity of GEN was unmodified after ion-pairing, precipitation or encapsulation into NPs. These results encourage their use for treatment for infections caused by GEN-sensitive intracellular bacteria. PMID:21115143

  6. Signal Inhibitory Receptor on Leukocytes-1 Limits the Formation of Neutrophil Extracellular Traps, but Preserves Intracellular Bacterial Killing.

    PubMed

    Van Avondt, Kristof; van der Linden, Maarten; Naccache, Paul H; Egan, David A; Meyaard, Linde

    2016-05-01

    In response to microbial invasion, neutrophils release neutrophil extracellular traps (NETs) to trap and kill extracellular microbes. Alternatively, NET formation can result in tissue damage in inflammatory conditions and may perpetuate autoimmune disease. Intervention strategies that are aimed at modifying pathogenic NET formation should ideally preserve other neutrophil antimicrobial functions. We now show that signal inhibitory receptor on leukocytes-1 (SIRL-1) attenuates NET release by human neutrophils in response to distinct triggers, including opsonized Staphylococcus aureus and inflammatory danger signals. NET release has different kinetics depending on the stimulus, and rapid NET formation is independent of NADPH oxidase activity. In line with this, we show that NET release and reactive oxygen species production upon challenge with opsonized S. aureus require different signaling events. Importantly, engagement of SIRL-1 does not affect bacterially induced production of reactive oxygen species, and intracellular bacterial killing by neutrophils remains intact. Thus, our studies define SIRL-1 as an intervention point of benefit to suppress NET formation in disease while preserving intracellular antimicrobial defense. PMID:27016607

  7. Molecular mechanisms of cell–cell spread of intracellular bacterial pathogens

    PubMed Central

    Ireton, Keith

    2013-01-01

    Several bacterial pathogens, including Listeria monocytogenes, Shigella flexneri and Rickettsia spp., have evolved mechanisms to actively spread within human tissues. Spreading is initiated by the pathogen-induced recruitment of host filamentous (F)-actin. F-actin forms a tail behind the microbe, propelling it through the cytoplasm. The motile pathogen then encounters the host plasma membrane, forming a bacterium-containing protrusion that is engulfed by an adjacent cell. Over the past two decades, much progress has been made in elucidating mechanisms of F-actin tail formation. Listeria and Shigella produce tails of branched actin filaments by subverting the host Arp2/3 complex. By contrast, Rickettsia forms tails with linear actin filaments through a bacterial mimic of eukaryotic formins. Compared with F-actin tail formation, mechanisms controlling bacterial protrusions are less well understood. However, recent findings have highlighted the importance of pathogen manipulation of host cell–cell junctions in spread. Listeria produces a soluble protein that enhances bacterial protrusions by perturbing tight junctions. Shigella protrusions are engulfed through a clathrin-mediated pathway at ‘tricellular junctions’—specialized membrane regions at the intersection of three epithelial cells. This review summarizes key past findings in pathogen spread, and focuses on recent developments in actin-based motility and the formation and internalization of bacterial protrusions. PMID:23864553

  8. Assay Development for Image-Based Quantification of Intracellular Bacterial Replication and Analysis of the Innate Immune Response to Infection.

    PubMed

    Miller, Alexandra H; Vayttaden, Sharat J; Al-Khodor, Souhaila; Fraser, Iain D C

    2015-11-01

    Severe bacterial infection can lead to inflammation, host tissue damage, and ultimately disseminated septic shock. The mammalian innate immune system responds to microbial infection through the detection of invariant pathogen-associated molecular patterns (PAMPs) by a range of pattern recognition receptors (PRRs) expressed by the host cell. A successful immune response involves tightly coordinated signaling from these receptors, leading to a robust transcriptional response producing cytokines and antimicrobial effectors. While the PRR-expressing phagocytes of the host innate immune system function to contain and degrade internalized bacteria through pathways such as selective autophagy, pathogenic bacteria may subvert this process to replicate in the host cell. We describe the development of imaging assays to investigate these host-pathogen interactions through gene perturbation screens, which could lead to the identification of novel effectors of the host response to bacterial infection. We identify markers of coordinated initial signaling in macrophages challenged with ligands to PRRs of the toll-like receptor (TLR) family and compare this response to that induced by intact bacteria of the Burkholderia cenocepacia complex (Bcc), an opportunistic pathogen that causes life-threatening infections in patients with cystic fibrosis and chronic granulomatous disease. Bcc has been shown to escape the endocytic pathway, activate selective autophagy, and replicate within human macrophages. We demonstrate robust image-based quantification of multiple stages of Bcc infection of macrophages: ubiquitin tagging of cytosolic bacteria, recruitment of selective autophagy effector proteins, and intracellular bacterial replication, and we show perturbation of bacterial replication using drug treatment or siRNA-based gene knockdown. The described panel of imaging assays can be extended to other bacterial infections and pathogenic ligand combinations where high-content siRNA screening could provide significant new insight into regulation of the innate immune response to infection. PMID:26505731

  9. Modulation of neutrophil superoxide response and intracellular diacylglyceride levels by the bacterial pigment pyocyanin.

    PubMed Central

    Muller, M; Sorrell, T C

    1997-01-01

    Low concentrations of pyocyanin are reported to enhance superoxide production by human neutrophils exposed to various stimuli, yet the mechanism remains unknown. Using lucigenin-enhanced chemiluminescence, we examined the kinetics of the neutrophil superoxide response in the presence of pyocyanin. At all concentrations (12.5 to 200 microM), pyocyanin decreased the peak superoxide response while prolonging the duration of the response. The prolonged response may be associated with an observed increase in intracellular diacylglyceride levels due to pyocyanin exposure. PMID:9169797

  10. Bacterial translocation affects intracellular neuroinflammatory pathways in a depression-like model in rats.

    PubMed

    Martín-Hernández, David; Caso, Javier R; Bris, Álvaro G; Maus, Sandra R; Madrigal, José L M; García-Bueno, Borja; MacDowell, Karina S; Alou, Luis; Gómez-Lus, Maria Luisa; Leza, Juan C

    2016-04-01

    Recent studies have suggested that depression is accompanied by an increased intestinal permeability which would be related to the inflammatory pathophysiology of the disease. This study aimed to evaluate whether experimental depression presents with bacterial translocation that in turn can lead to the TLR-4 in the brain affecting the mitogen-activated protein kinases (MAPK) and antioxidant pathways. Male Wistar rats were exposed to chronic mild stress (CMS) and the intestinal integrity, presence of bacteria in tissues and plasma lipopolysaccharide levels were analyzed. We also studied the expression in the prefrontal cortex of activated forms of MAPK and some of their activation controllers and the effects of CMS on the antioxidant Nrf2 pathway. Our results indicate that after exposure to a CMS protocol there is increased intestinal permeability and bacterial translocation. CMS also increases the expression of the activated form of the MAPK p38 while decreasing the expression of the antioxidant transcription factor Nrf2. The actions of antibiotic administration to prevent bacterial translocation on elements of the MAPK and Nrf2 pathways indicate that the translocated bacteria are playing a role in these effects. In effect, our results propose a role of the translocated bacteria in the pathophysiology of depression through the p38 MAPK pathway which could aggravate the neuroinflammation and the oxidative/nitrosative damage present in this pathology. Moreover, our results reveal that the antioxidant factor Nrf2 and its activators may be involved in the consequences of the CMS on the brain. PMID:26686392

  11. A Salmonella Small Non-Coding RNA Facilitates Bacterial Invasion and Intracellular Replication by Modulating the Expression of Virulence Factors

    PubMed Central

    Gong, Hao; Vu, Gia-Phong; Bai, Yong; Chan, Elton; Wu, Ruobin; Yang, Edward; Liu, Fenyong; Lu, Sangwei

    2011-01-01

    Small non-coding RNAs (sRNAs) that act as regulators of gene expression have been identified in all kingdoms of life, including microRNA (miRNA) and small interfering RNA (siRNA) in eukaryotic cells. Numerous sRNAs identified in Salmonella are encoded by genes located at Salmonella pathogenicity islands (SPIs) that are commonly found in pathogenic strains. Whether these sRNAs are important for Salmonella pathogenesis and virulence in animals has not been reported. In this study, we provide the first direct evidence that a pathogenicity island-encoded sRNA, IsrM, is important for Salmonella invasion of epithelial cells, intracellular replication inside macrophages, and virulence and colonization in mice. IsrM RNA is expressed in vitro under conditions resembling those during infection in the gastrointestinal tract. Furthermore, IsrM is found to be differentially expressed in vivo, with higher expression in the ileum than in the spleen. IsrM targets the mRNAs coding for SopA, a SPI-1 effector, and HilE, a global regulator of the expression of SPI-1 proteins, which are major virulence factors essential for bacterial invasion. Mutations in IsrM result in disregulation of expression of HilE and SopA, as well as other SPI-1 genes whose expression is regulated by HilE. Salmonella with deletion of isrM is defective in bacteria invasion of epithelial cells and intracellular replication/survival in macrophages. Moreover, Salmonella with mutations in isrM is attenuated in killing animals and defective in growth in the ileum and spleen in mice. Our study has shown that IsrM sRNA functions as a pathogenicity island-encoded sRNA directly involved in Salmonella pathogenesis in animals. Our results also suggest that sRNAs may represent a distinct class of virulence factors that are important for bacterial infection in vivo. PMID:21949647

  12. High-throughput, subpixel-precision analysis of bacterial morphogenesis and intracellular spatio-temporal dynamics

    PubMed Central

    Sliusarenko, Oleksii; Heinritz, Jennifer; Emonet, Thierry; Jacobs-Wagner, Christine

    2011-01-01

    Bacteria display various shapes and rely on complex spatial organization of their intracellular components for many cellular processes. This organization changes in response to internal and external cues. Quantitative, unbiased study of these spatio-temporal dynamics requires automated image analysis of large microscopy datasets. We have therefore developed MicrobeTracker, a versatile and high-throughput image analysis program that outlines and segments cells with subpixel precision, even in crowded images and mini-colonies, enabling cell lineage tracking. MicrobeTracker comes with an integrated accessory tool, SpotFinder, that precisely tracks foci of fluorescently labeled molecules inside cells. Using MicrobeTracker, we discover that the dynamics of the extensively-studied Escherichia coli Min oscillator depends on Min protein concentration, unveiling critical limitations in robustness within the oscillator. We also find that the fraction of MinD proteins oscillating increases with cell length, indicating that the oscillator has evolved to be most effective when cells attain an appropriate length. MicrobeTracker was also used to uncover novel aspects of morphogenesis and cell cycle regulation in Caulobacter crescentus. By tracking filamentous cells, we show that the chromosomal origin at the old pole is responsible for most replication/separation events while the others remain largely silent despite contiguous cytoplasm. This surprising position-dependent silencing is regulated by division. PMID:21414037

  13. Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling.

    PubMed

    Berens, Christian; Bisle, Stephanie; Klingenbeck, Leonie; Lhrmann, Anja

    2015-01-01

    The technique presented here allows one to analyze at which step a target protein, or alternatively a small molecule, interacts with the components of a signaling pathway. The method is based, on the one hand, on the inducible expression of a specific protein to initiate a signaling event at a defined and predetermined step in the selected signaling cascade. Concomitant expression, on the other hand, of the gene of interest then allows the investigator to evaluate if the activity of the expressed target protein is located upstream or downstream of the initiated signaling event, depending on the readout of the signaling pathway that is obtained. Here, the apoptotic cascade was selected as a defined signaling pathway to demonstrate protocol functionality. Pathogenic bacteria, such as Coxiella burnetii, translocate effector proteins that interfere with host cell death induction in the host cell to ensure bacterial survival in the cell and to promote their dissemination in the organism. The C. burnetii effector protein CaeB effectively inhibits host cell death after induction of apoptosis with UV-light or with staurosporine. To narrow down at which step CaeB interferes with the propagation of the apoptotic signal, selected proteins with well-characterized pro-apoptotic activity were expressed transiently in a doxycycline-inducible manner. If CaeB acts upstream of these proteins, apoptosis will proceed unhindered. If CaeB acts downstream, cell death will be inhibited. The test proteins selected were Bax, which acts at the level of the mitochondria, and caspase 3, which is the major executioner protease. CaeB interferes with cell death induced by Bax expression, but not by caspase 3 expression. CaeB, thus, interacts with the apoptotic cascade between these two proteins. PMID:26168006

  14. Coinfection of tick cell lines has variable effects on replication of intracellular bacterial and viral pathogens.

    PubMed

    Moniuszko, Anna; Rückert, Claudia; Alberdi, M Pilar; Barry, Gerald; Stevenson, Brian; Fazakerley, John K; Kohl, Alain; Bell-Sakyi, Lesley

    2014-06-01

    Ticks transmit various human and animal microbial pathogens and may harbour more than one pathogen simultaneously. Both viruses and bacteria can trigger, and may subsequently suppress, vertebrate host and arthropod vector anti-microbial responses. Microbial coinfection of ticks could lead to an advantage or disadvantage for one or more of the microorganisms. In this preliminary study, cell lines derived from the ticks Ixodes scapularis and Ixodes ricinus were infected sequentially with 2 arthropod-borne pathogens, Borrelia burgdorferi s.s., Ehrlichia ruminantium, or Semliki Forest virus (SFV), and the effect of coinfection on the replication of these pathogens was measured. Prior infection of tick cell cultures with the spirochaete B. burgdorferi enhanced subsequent replication of the rickettsial pathogen E. ruminantium whereas addition of spirochaetes to cells infected with E. ruminantium had no effect on growth of the latter. Both prior and subsequent presence of B. burgdorferi also had a positive effect on SFV replication. Presence of E. ruminantium or SFV had no measurable effect on B. burgdorferi growth. In tick cells infected first with E. ruminantium and then with SFV, virus replication was significantly higher across all time points measured (24, 48, 72h post infection), while presence of the virus had no detectable effect on bacterial growth. When cells were infected first with SFV and then with E. ruminantium, there was no effect on replication of either pathogen. The results of this preliminary study indicate that interplay does occur between different pathogens during infection of tick cells. Further study is needed to determine if this results from direct pathogen-pathogen interaction or from effects on host cell defences, and to determine if these observations also apply in vivo in ticks. If presence of one pathogen in the tick vector results in increased replication of another, this could have implications for disease transmission and incidence. PMID:24685441

  15. Self-assembling, protein-based intracellular bacterial organelles: emerging vehicles for encapsulating, targeting and delivering therapeutical cargoes

    PubMed Central

    2011-01-01

    Many bacterial species contain intracellular nano- and micro-compartments consisting of self-assembling proteins that form protein-only shells. These structures are built up by combinations of a reduced number of repeated elements, from 60 repeated copies of one unique structural element self-assembled in encapsulins of 24 nm to 10,000-20,000 copies of a few protein species assembled in a organelle of around 100-150 nm in cross-section. However, this apparent simplicity does not correspond to the structural and functional sophistication of some of these organelles. They package, by not yet definitely solved mechanisms, one or more enzymes involved in specific metabolic pathways, confining such reactions and sequestering or increasing the inner concentration of unstable, toxics or volatile intermediate metabolites. From a biotechnological point of view, we can use the self assembling properties of these particles for directing shell assembling and enzyme packaging, mimicking nature to design new applications in biotechnology. Upon appropriate engineering of the building blocks, they could act as a new family of self-assembled, protein-based vehicles in Nanomedicine to encapsulate, target and deliver therapeutic cargoes to specific cell types and/or tissues. This would provide a new, intriguing platform of microbial origin for drug delivery. PMID:22046962

  16. Phosphatidylinositol 3-Kinase p110δ Isoform Regulates CD8+ T Cell Responses during Acute Viral and Intracellular Bacterial Infections.

    PubMed

    Gracias, Donald T; Boesteanu, Alina C; Fraietta, Joseph A; Hope, Jennifer L; Carey, Alison J; Mueller, Yvonne M; Kawalekar, Omkar U; Fike, Adam J; June, Carl H; Katsikis, Peter D

    2016-02-01

    The p110δ isoform of PI3K is known to play an important role in immunity, yet its contribution to CTL responses has not been fully elucidated. Using murine p110δ-deficient CD8(+) T cells, we demonstrated a critical role for the p110δ subunit in the generation of optimal primary and memory CD8(+) T cell responses. This was demonstrated in both acute viral and intracellular bacterial infections in mice. We show that p110δ signaling is required for CD8(+) T cell activation, proliferation and effector cytokine production. We provide evidence that the effects of p110δ signaling are mediated via Akt activation and through the regulation of TCR-activated oxidative phosphorylation and aerobic glycolysis. In light of recent clinical trials that employ drugs targeting p110δ in certain cancers and other diseases, our study suggests caution in using these drugs in patients, as they could potentially increase susceptibility to infectious diseases. These studies therefore reveal a novel and direct role for p110δ signaling in in vivo CD8(+) T cell immunity to microbial pathogens. PMID:26740110

  17. Invasion of the Central Nervous System by Intracellular Bacteria

    PubMed Central

    Drevets, Douglas A.; Leenen, Pieter J. M.; Greenfield, Ronald A.

    2004-01-01

    Infection of the central nervous system (CNS) is a severe and frequently fatal event during the course of many diseases caused by microbes with predominantly intracellular life cycles. Examples of these include the facultative intracellular bacteria Listeria monocytogenes, Mycobacterium tuberculosis, and Brucella and Salmonella spp. and obligate intracellular microbes of the Rickettsiaceae family and Tropheryma whipplei. Unfortunately, the mechanisms used by intracellular bacterial pathogens to enter the CNS are less well known than those used by bacterial pathogens with an extracellular life cycle. The goal of this review is to elaborate on the means by which intracellular bacterial pathogens establish infection within the CNS. This review encompasses the clinical and pathological findings that pertain to the CNS infection in humans and includes experimental data from animal models that illuminate how these microbes enter the CNS. Recent experimental data showing that L. monocytogenes can invade the CNS by more than one mechanism make it a useful model for discussing the various routes for neuroinvasion used by intracellular bacterial pathogens. PMID:15084504

  18. Obliging children.

    PubMed

    Lyons, Barry

    2011-01-01

    Children may sometimes undergo healthcare procedures that are not intended to improve their health status. Such interventions might include the use of young children as bone marrow donors or their enrolment in non-therapeutic research. One of the justifications used to legitimise these interventions is the premise that children have obligations to others; to their family in the case of related bone marrow transplantation, and to wider society in the case of non-therapeutic research. However, this 'obligation model' (the notion that children possess positive obligations to advance the health status of others) fails as a justificatory paradigm because it is based upon a confusion, identified by Hart, between two notions; that of 'being under an obligation to do something' and that of 'being obliged to do something'. Instead the 'obligation model' is a device employed to put a justificatory gloss upon a consequentialist decision-making process; removing the legitimising gloss allows for a more transparent look at the conflict between parental rights and an individual child's right to bodily integrity. PMID:21289034

  19. Characterization of a Lipopolysaccharide-Targeted Monoclonal Antibody and Its Variable Fragments as Candidates for Prophylaxis against the Obligate Intracellular Bacterial Pathogen Coxiella burnetii

    PubMed Central

    Peng, Ying; Schoenlaub, Laura; Elliott, Alexandra; Mitchell, William J.

    2014-01-01

    Our previous study demonstrated that treatment of Coxiella burnetii with the phase I lipopolysaccharide (PI-LPS)-targeted monoclonal antibody (MAb) 1E4 significantly inhibited C. burnetii infection in mice, suggesting that 1E4 is a protective MAb. To determine whether passive transfer of antibodies (Abs) can provide protection against C. burnetii natural infection, we examined if passive transfer of 1E4 would protect SCID mice against C. burnetii aerosol infection. The results indicated that 1E4 conferred significant protection against aerosolized C. burnetii, suggesting that 1E4 may be useful for preventing C. burnetii natural infection. To further understand the mechanisms of 1E4-mediated protection and to test the possibility of using humanized 1E4 to prevent C. burnetii infection, we examined whether the Fab fragment of 1E4 (Fab1E4), a recombinant murine single-chain variable fragment (muscFv1E4), and a humanized single-chain variable fragment (huscFv1E4) retained the ability of 1E4 to inhibit C. burnetii infection. The results indicated that Fab1E4, muscFv1E4, and huscFv1E4 were able to inhibit C. burnetii infection in mice but that their ability to inhibit C. burnetii infection was lower than that of 1E4. In addition, treatment of C. burnetii with Fab1E4, muscFv1E4, or huscFv1E4 can block C. burnetii infection of macrophages. Interestingly, treatment of C. burnetii with huscFv1E4 can significantly reduce C. burnetii infectivity in human macrophages. This report provides the first evidence to demonstrate that the humanized variable fragments of an LPS-specific MAb can neutralize C. burnetii infection and appears to be a promising step toward the potential use of a humanized MAb as emergency prophylaxis against C. burnetii exposure. PMID:25114119

  20. Anaplasma phagocytophilum APH_1387 Is Expressed throughout Bacterial Intracellular Development and Localizes to the Pathogen-Occupied Vacuolar Membrane▿

    PubMed Central

    Huang, Bernice; Troese, Matthew J.; Ye, Shaojing; Sims, Jonathan T.; Galloway, Nathan L.; Borjesson, Dori L.; Carlyon, Jason A.

    2010-01-01

    Obligate vacuolar pathogens produce proteins that localize to the host cell-derived membranes of the vacuoles in which they reside, yielding unique organelles that are optimally suited for pathogen survival. Anaplasma phagocytophilum is an obligate vacuolar bacterium that infects neutrophils and causes the emerging and potentially fatal disease human granulocytic anaplasmosis. Here we identified APH_1387 as the first A. phagocytophilum-derived protein that associates with the A. phagocytophilum-occupied vacuolar membrane (AVM). APH_1387, also referred to as P100, is a 61.4-kDa acidic protein that migrates with an apparent molecular weight of 115 kDa on SDS-PAGE gels. It carries 3 tandem direct repeats that comprise 58% of the protein. Each APH_1387 repeat carries a bilobed hydrophobic alpha-helix domain, which is a structural characteristic that is consistent with the structure of chlamydia-derived proteins that traverse inclusion membranes. APH_1387 is not detectable on the surfaces of A. phagocytophilum dense core organisms bound at the HL-60 cell surface, but abundant APH_1387 is detected on the surfaces of intravacuolar reticulate cell and dense core organisms. APH_1387 accumulates on the AVM throughout infection. It associates with the AVM in human HL-60, THP-1, and HMEC-1 cells and tick ISE6 cells. APH_1387 is expressed and localizes to the AVM in neutrophils recovered from A. phagocytophilum-infected mice. This paper presents the first direct evidence that A. phagocytophilum actively modifies its host cell-derived vacuole. PMID:20212090

  1. The pleiotropic transcriptional response of Mycobacterium tuberculosis to vitamin C is robust and overlaps with the bacterial response to multiple intracellular stresses.

    PubMed

    Sikri, Kriti; Batra, Sakshi Dhingra; Nandi, Malobi; Kumari, Priyanka; Taneja, Neetu Kumra; Tyagi, Jaya Sivaswami

    2015-04-01

    Mycobacterium tuberculosis (Mtb) owes its success as a pathogen in large measure to its ability to exist in a persistent state of 'dormancy' resulting in a lifelong latent tuberculosis (TB) infection. An understanding of bacterial adaptation during dormancy will help in devising approaches to counter latent TB infection. In vitro models have provided valuable insights into bacterial adaptation; however, they have limitations because they do not disclose the bacterial response to the intracellular environment wherein the bacteria are simultaneously exposed to multiple stresses. We describe the pleiotropic response of Mtb in the vitamin C (vit C) model of dormancy developed in our laboratory. Vit C mediates a rapid regulation of genes representing ~14 % of the genome in Mtb cultures. The upregulated genes were better represented in lipid, intermediary metabolism and regulatory protein categories. The downregulated genes mainly related to virulence, detoxification, information pathways and cell wall processes. A comparison of this response to that in other models indicates that vit C generates a multiple-stress environment for axenic Mtb cultures that resembles a macrophage-like environment. The bacterial response to vit C resembles responses to gaseous stresses such as hypoxia and nitric oxide, oxidative and nitrosative stresses, nutrient starvation and, notably, the activated macrophage environment itself. These responses demonstrate that the influence of vit C on Mtb gene expression extends well beyond the DevR dormancy regulon. A detailed characterization of the response to vit C is expected to disclose useful strategies to counter the adaptive mechanisms essential to Mtb dormancy. PMID:25645949

  2. Intracellular replication of Staphylococcus aureus in mature phagolysosomes in macrophages precedes host cell death, and bacterial escape and dissemination.

    PubMed

    Flannagan, Ronald S; Heit, Bryan; Heinrichs, David E

    2016-04-01

    The success of Staphylococcus aureus as a pathogen is partly attributable to its ability to thwart host innate immune responses, which includes resisting the antimicrobial functions of phagocytes. Here, we have studied the interaction of methicillin-resistant S. aureus (MRSA) strain USA300 with murine RAW 264.7 and primary human macrophages using molecular imaging and single cell analysis to obtain an unprecedented understanding of the interaction between the macrophage and MRSA. Herein we demonstrate that macrophages fail to control intracellular infection by MRSA USA300 despite trafficking the bacteria into mature phagolysosomes. Using fluorescence-based proliferation assays we also show that intracellular staphylococci proliferate and that replication commences while the bacteria are residing in mature phagolysosomes hours after initial phagocytosis. Finally, live-cell fluorescence video microscopy allowed for unprecedented visual insight into the escape of MRSA from macrophages, demonstrating that the macrophages die through a pathway characterized by membrane blebbing and activation of caspase-3 followed by acquisition of the vital dye propidium iodide. Moreover, cell death precedes the emergence of MRSA from infected macrophages, and these events can be ablated by prolonged exposure of infected phagocytes to gentamicin. PMID:26408990

  3. Diversity of Bacterial Endosymbionts of Environmental Acanthamoeba Isolates▿ †

    PubMed Central

    Schmitz-Esser, Stephan; Toenshoff, Elena R.; Haider, Susanne; Heinz, Eva; Hoenninger, Verena M.; Wagner, Michael; Horn, Matthias

    2008-01-01

    Free-living amoebae are frequent hosts for bacterial endosymbionts. In this study, the symbionts of eight novel environmental Acanthamoeba strains isolated from different locations worldwide were characterized. Phylogenetic analysis revealed that they were related to one of four evolutionary lineages of amoeba symbionts recognized previously. This study provides evidence for the existence of only a small number of phylogenetically well-separated groups of obligate intracellular endosymbionts of acanthamoebae with global distribution. PMID:18641160

  4. Complete Bacteriophage Transfer in a Bacterial Endosymbiont (Wolbachia) Determined by Targeted Genome Capture

    PubMed Central

    Kent, Bethany N.; Salichos, Leonidas; Gibbons, John G.; Rokas, Antonis; Newton, Irene L. G.; Clark, Michael E.; Bordenstein, Seth R.

    2011-01-01

    Bacteriophage flux can cause the majority of genetic diversity in free-living bacteria. This tenet of bacterial genome evolution generally does not extend to obligate intracellular bacteria owing to their reduced contact with other microbes and a predominance of gene deletion over gene transfer. However, recent studies suggest intracellular coinfections in the same host can facilitate exchange of mobile elements between obligate intracellular bacteria—a means by which these bacteria can partially mitigate the reductive forces of the intracellular lifestyle. To test whether bacteriophages transfer as single genes or larger regions between coinfections, we sequenced the genome of the obligate intracellular Wolbachia strain wVitB from the parasitic wasp Nasonia vitripennis and compared it against the prophage sequences of the divergent wVitA coinfection. We applied, for the first time, a targeted sequence capture array to specifically trap the symbiont's DNA from a heterogeneous mixture of eukaryotic, bacterial, and viral DNA. The tiled array successfully captured the genome with 98.3% efficiency. Examination of the genome sequence revealed the largest transfer of bacteriophage and flanking genes (52.2 kb) to date between two obligate intracellular coinfections. The mobile element transfer occurred in the recent evolutionary past based on the 99.9% average nucleotide identity of the phage sequences between the two strains. In addition to discovering an evolutionary recent and large-scale horizontal phage transfer between coinfecting obligate intracellular bacteria, we demonstrate that “targeted genome capture” can enrich target DNA to alleviate the problem of isolating symbiotic microbes that are difficult to culture or purify from the conglomerate of organisms inside eukaryotes. PMID:21292630

  5. Extracellular ATP protects against sepsis through macrophage P2X7 purinergic receptors by enhancing intracellular bacterial killing.

    PubMed

    Csóka, Balázs; Németh, Zoltán H; Törő, Gábor; Idzko, Marco; Zech, Andreas; Koscsó, Balázs; Spolarics, Zoltán; Antonioli, Luca; Cseri, Karolina; Erdélyi, Katalin; Pacher, Pál; Haskó, György

    2015-09-01

    Extracellular ATP binds to and signals through P2X7 receptors (P2X7Rs) to modulate immune function in both inflammasome-dependent and -independent manners. In this study, P2X7(-/-) mice, the pharmacological agonists ATP-magnesium salt (Mg-ATP; 100 mg/kg, EC50 ≈ 1.32 mM) and benzoylbenzoyl-ATP (Bz-ATP; 10 mg/kg, EC50 ≈ 285 μM), and antagonist oxidized ATP (oxi-ATP; 40 mg/kg, IC50 ≈ 100 μM) were used to show that P2X7R activation is crucial for the control of mortality, bacterial dissemination, and inflammation in cecal ligation and puncture-induced polymicrobial sepsis in mice. Our results with P2X7(-/-) bone marrow chimeric mice, adoptive transfer of peritoneal macrophages, and myeloid-specific P2X7(-/-) mice indicate that P2X7R signaling on macrophages is essential for the protective effect of P2X7Rs. P2X7R signaling protects through enhancing bacterial killing by macrophages, which is independent of the inflammasome. By using the connexin (Cx) channel inhibitor Gap27 (0.1 mg/kg, IC50 ≈ 0.25 μM) and pannexin channel inhibitor probenecid (10 mg/kg, IC50 ≈ 11.7 μM), we showed that ATP release through Cx is important for inhibiting inflammation and bacterial burden. In summary, targeting P2X7Rs provides a new opportunity for harnessing an endogenous protective immune mechanism in the treatment of sepsis. PMID:26060214

  6. Alteration of intracellular protein expressions as a key mechanism of the deterioration of bacterial denitrification caused by copper oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Su, Yinglong; Zheng, Xiong; Chen, Yinguang; Li, Mu; Liu, Kun

    2015-10-01

    The increasing production and utilization of copper oxide nanoparticles (CuO NPs) result in the releases into the environment. However, the influence of CuO NPs on bacterial denitrification, one of the most important pathways to transform nitrate to dinitrogen in environment, has seldom been studied. Here we reported that CuO NPs caused a significant alteration of key protein expressions of a model denitrifier, Paracoccus denitrificans, leading to severe inhibition to denitrification. Total nitrogen removal efficiency was decreased from 98.3% to 62.1% with the increase of CuO NPs from 0.05 to 0.25 mg/L. Cellular morphology and integrity studies indicated that nanoparticles entered the cells. The proteomic bioinformatics analysis showed that CuO NPs caused regulation of proteins involved in nitrogen metabolism, electron transfer and substance transport. The down-regulation of GtsB protein (responsible for glucose transport) decreased the production of NADH (electron donor for denitrification). Also, the expressions of key electron-transfer proteins (including NADH dehydrogenase and cytochrome) were suppressed by CuO NPs, which adversely affected electrons transfer for denitrification. Further investigation revealed that CuO NPs significantly inhibited the expressions and catalytic activities of nitrate reductase and nitrite reductase. These results provided a fundamental understanding of the negative influences of CuO NPs on bacterial denitrification.

  7. Alteration of intracellular protein expressions as a key mechanism of the deterioration of bacterial denitrification caused by copper oxide nanoparticles

    PubMed Central

    Su, Yinglong; Zheng, Xiong; Chen, Yinguang; Li, Mu; Liu, Kun

    2015-01-01

    The increasing production and utilization of copper oxide nanoparticles (CuO NPs) result in the releases into the environment. However, the influence of CuO NPs on bacterial denitrification, one of the most important pathways to transform nitrate to dinitrogen in environment, has seldom been studied. Here we reported that CuO NPs caused a significant alteration of key protein expressions of a model denitrifier, Paracoccus denitrificans, leading to severe inhibition to denitrification. Total nitrogen removal efficiency was decreased from 98.3% to 62.1% with the increase of CuO NPs from 0.05 to 0.25 mg/L. Cellular morphology and integrity studies indicated that nanoparticles entered the cells. The proteomic bioinformatics analysis showed that CuO NPs caused regulation of proteins involved in nitrogen metabolism, electron transfer and substance transport. The down-regulation of GtsB protein (responsible for glucose transport) decreased the production of NADH (electron donor for denitrification). Also, the expressions of key electron-transfer proteins (including NADH dehydrogenase and cytochrome) were suppressed by CuO NPs, which adversely affected electrons transfer for denitrification. Further investigation revealed that CuO NPs significantly inhibited the expressions and catalytic activities of nitrate reductase and nitrite reductase. These results provided a fundamental understanding of the negative influences of CuO NPs on bacterial denitrification. PMID:26508362

  8. Alteration of intracellular protein expressions as a key mechanism of the deterioration of bacterial denitrification caused by copper oxide nanoparticles.

    PubMed

    Su, Yinglong; Zheng, Xiong; Chen, Yinguang; Li, Mu; Liu, Kun

    2015-01-01

    The increasing production and utilization of copper oxide nanoparticles (CuO NPs) result in the releases into the environment. However, the influence of CuO NPs on bacterial denitrification, one of the most important pathways to transform nitrate to dinitrogen in environment, has seldom been studied. Here we reported that CuO NPs caused a significant alteration of key protein expressions of a model denitrifier, Paracoccus denitrificans, leading to severe inhibition to denitrification. Total nitrogen removal efficiency was decreased from 98.3% to 62.1% with the increase of CuO NPs from 0.05 to 0.25 mg/L. Cellular morphology and integrity studies indicated that nanoparticles entered the cells. The proteomic bioinformatics analysis showed that CuO NPs caused regulation of proteins involved in nitrogen metabolism, electron transfer and substance transport. The down-regulation of GtsB protein (responsible for glucose transport) decreased the production of NADH (electron donor for denitrification). Also, the expressions of key electron-transfer proteins (including NADH dehydrogenase and cytochrome) were suppressed by CuO NPs, which adversely affected electrons transfer for denitrification. Further investigation revealed that CuO NPs significantly inhibited the expressions and catalytic activities of nitrate reductase and nitrite reductase. These results provided a fundamental understanding of the negative influences of CuO NPs on bacterial denitrification. PMID:26508362

  9. Identification of New Single Nucleotide Polymorphism-Based Markers for Inter- and Intraspecies Discrimination of Obligate Bacterial Parasites (Pasteuria spp.) of Invertebrates ?

    PubMed Central

    Mauchline, Tim H.; Knox, Rachel; Mohan, Sharad; Powers, Stephen J.; Kerry, Brian R.; Davies, Keith G.; Hirsch, Penny R.

    2011-01-01

    Protein-encoding and 16S rRNA genes of Pasteuria penetrans populations from a wide range of geographic locations were examined. Most interpopulation single nucleotide polymorphisms (SNPs) were detected in the 16S rRNA gene. However, in order to fully resolve all populations, these were supplemented with SNPs from protein-encoding genes in a multilocus SNP typing approach. Examination of individual 16S rRNA gene sequences revealed the occurrence of cryptic SNPs which were not present in the consensus sequences of any P. penetrans population. Additionally, hierarchical cluster analysis separated P. penetrans 16S rRNA gene clones into four groups, and one of which contained sequences from the most highly passaged population, demonstrating that it is possible to manipulate the population structure of this fastidious bacterium. The other groups were made from representatives of the other populations in various proportions. Comparison of sequences among three Pasteuria species, namely, P. penetrans, P. hartismeri, and P. ramosa, showed that the protein-encoding genes provided greater discrimination than the 16S rRNA gene. From these findings, we have developed a toolbox for the discrimination of Pasteuria at both the inter- and intraspecies levels. We also provide a model to monitor genetic variation in other obligate hyperparasites and difficult-to-culture microorganisms. PMID:21803895

  10. NCI & Division Obligations

    Cancer.gov

    Displays obligations for grants, contracts, training fellowships, intramural research, and management and support, including the number of grant awards, funding amounts, and percent of the total NCI budget.

  11. Ultrastructural Changes in an Obligately Barophilic Marine Bacterium after Decompression

    PubMed Central

    Chastain, Roger A.; Yayanos, A. Aristides

    1991-01-01

    The bacterial isolate MT-41 from 10,476 m, nearly the greatest ocean depth, is obligately barophilic. The purpose of this study was to describe the morphological changes in MT-41 due to nearly isothermal decompression followed by incubation at atmospheric pressure. Two cultures were grown at 103.5 MPa and 2°C and then decompressed to atmospheric pressure (0.101 MPa). One of the cultures was fixed just before decompression. The other culture, kept at 0°C, was sampled immediately and four more times over 168 h. The number of CFU (assayed at 103.5 MPa and 2°C) declined with incubation time at atmospheric pressure. Decompression itself did not lead to immediate morphological changes. The ultrastructure, however, was altered with increasing time at atmospheric pressure. The first aberrations were intracellular vesicles and membrane fragments in the medium. After these changes were plasmolysis, cell lysis, the formation of extracellular vesicles, and the formation of ghost cells. Intact cells in the longest incubation at atmospheric pressure had the normal cytoplasmic granularity suggestive of ribosomes but had few and poorly stained fibrils in the bacterial nucleoids. From the practical standpoint, samples of hadal deep-sea regions need to be fixed either in situ or shortly after arrival at the sea surface even when recovered in insulated sampling gear. This should prevent drastic structural degradation of sampled cells, thus allowing both accurate estimates of deep-sea benthic standing stock and realistic morphological descriptions. Images PMID:16348489

  12. Strategies of genomic integration within insect-bacterial mutualisms

    PubMed Central

    Wernegreen, Jennifer J.

    2013-01-01

    Insects, the most diverse group of macroorganisms with 900,000 known species, have been a rich playground for the evolution of symbiotic associations. Symbionts of this enormous animal group include a range of microbial partners. Insects are prone to establishing relationships with intracellular bacteria, which include the most intimate, highly integrated mutualisms known in the biological world. In recent years, an explosion of genomic studies has offered new insights into the molecular, functional, and evolutionary consequences of these insect-bacterial partnerships. In this review, I highlight some insights from genome sequences of bacterial endosymbionts and select insect hosts. Notably, comparisons of facultative versus obligate bacterial mutualists have revealed distinct genome features representing different stages along a shared trajectory of genome reduction. Bacteria associated with the cedar aphid offer a snapshot of a transition from facultative to obligate mutualism, illustrating the genomic basis of this key step along the symbiotic spectrum. In addition, genomes of stable, dual bacterial symbionts reflect independent instances of astonishing metabolic integration. In these systems, synthesis of key nutrients, and perhaps basic cellular processes, require collaboration among co-residing bacteria and their insect host. These findings provide a launching point for a new era of genomic explorations of bacterial-animal symbioses. Future studies promise to reveal symbiotic strategies across a broad ecological and phylogenetic range, to clarify key transitions along a spectrum of interaction types, and to fuel new experimental approaches to dissect the mechanistic basis of intimate host-symbiont associations. PMID:22983037

  13. Obesity and obligation.

    PubMed

    Jeppsson, Sofia

    2015-03-01

    The belief that obese people ought to lose weight and keep it off is widespread, and has a profound negative impact on the lives of the obese. I argue in this paper that most obese people have no such obligation, even if obesity is bad, and caused by calorie input exceeding output. Obese people do not have an obligation to achieve long-term weight loss if this is impossible for them, is worse than the alternative, or requires such an enormous effort in relation to what stands to be gained that this option is supererogatory rather than obligatory. It is highly plausible that most obese people fall into one of these three groups. Politicians may still have obligations to fight obesity, but they ought to do so through progressive politics rather than blaming and shaming. PMID:25843121

  14. The Serials Manager's Obligation.

    ERIC Educational Resources Information Center

    Tuttle, Marcia

    1987-01-01

    Discusses both the serials manager's external relationships with subscription agents and journal publishers and his/her obligation to be an equal and respected participant in acquiring information for users. Methods of gaining equality are considered, including education, communication with colleagues and vendors' representatives, and informed

  15. GRANDPARENTS' ENTITLEMENTS AND OBLIGATIONS

    PubMed Central

    Draper, Heather

    2013-01-01

    In this article, it is argued that grandparents' obligations originate from parental obligations (i.e from the relationship they have with their children, the parents of their grandchildren) and not from the role of grandparent per se, and any entitlements flow from the extent to which these obligations are met. The position defended is, therefore, that grandparents qua grandparents are not entitled to form or continue relationships with their grandchildren. A continuation of grandparent-grandchildren relationships may be in the interests of children, but the grandparental nature of the relationship is not decisive. What counts is the extent to which relationships children have with any adults who are not their parents are is significant to them. Sometimes, however, grandparents become parents or co-parents of their grandchildren. They then gain parental rights, and as such are as entitled, ceteris parius, as any parent to expect their relationship with the child to continue. The issue of grandparents' entitlements can come to the fore when parents separate, and grandparents are unhappy with the access they have to their grandchildren. Grandparents' obligations may become a particular issue when parents die, struggle, or fail to care for their children. This article focuses particularly on these kinds of circumstances. PMID:23718643

  16. Dehalococcoides mccartyi gen. nov., sp. nov., obligately organohalide-respiring anaerobic bacteria relevant to halogen cycling and bioremediation, belong to a novel bacterial class, Dehalococcoidia classis nov., order Dehalococcoidales ord. nov. and family Dehalococcoidaceae fam. nov., within the phylum Chloroflexi.

    PubMed

    Löffler, Frank E; Yan, Jun; Ritalahti, Kirsti M; Adrian, Lorenz; Edwards, Elizabeth A; Konstantinidis, Konstantinos T; Müller, Jochen A; Fullerton, Heather; Zinder, Stephen H; Spormann, Alfred M

    2013-02-01

    Six obligately anaerobic bacterial isolates (195(T), CBDB1, BAV1, VS, FL2 and GT) with strictly organohalide-respiring metabolisms were obtained from chlorinated solvent-contaminated aquifers, contaminated and uncontaminated river sediments or anoxic digester sludge. Cells were non-motile with a disc-shaped morphology, 0.3-1 µm in diameter and 0.1-0.2 µm thick, and characteristic indentations on opposite flat sides of the cell. Growth occurred in completely synthetic, reduced medium amended with a haloorganic electron acceptor (mostly chlorinated but also some brominated compounds), hydrogen as electron donor, acetate as carbon source, and vitamins. No other growth-supporting redox couples were identified. Aqueous hydrogen consumption threshold concentrations were <1 nM. Growth ceased when vitamin B(12) was omitted from the medium. Addition of sterile cell-free supernatant of Dehalococcoides-containing enrichment cultures enhanced dechlorination and growth of strains 195 and FL2, suggesting the existence of so-far unidentified stimulants. Dechlorination occurred between pH 6.5 and 8.0 and over a temperature range of 15-35 °C, with an optimum growth temperature between 25 and 30 °C. The major phospholipid fatty acids were 14 : 0 (15.7 mol%), br15 : 0 (6.2 mol%), 16 : 0 (22.7 mol%), 10-methyl 16 : 0 (25.8 mol%) and 18 : 0 (16.6 mol%). Unusual furan fatty acids including 9-(5-pentyl-2-furyl)-nonanoate and 8-(5-hexyl-2-furyl)-octanoate were detected in strains FL2, BAV1 and GT, but not in strains 195(T) and CBDB1. The 16S rRNA gene sequences of the six isolates shared more than 98 % identity, and phylogenetic analysis revealed an affiliation with the phylum Chloroflexi and more than 10 % sequence divergence from other described isolates. The genome sizes and G+C contents ranged from 1.34 to 1.47 Mbp and 47 to 48.9 mol% G+C, respectively. Based on 16S rRNA gene sequence comparisons, genome-wide average nucleotide identity and phenotypic characteristics, the organohalide-respiring isolates represent a new genus and species, for which the name Dehalococcoides mccartyi gen. nov., sp. nov. is proposed. Isolates BAV1 ( = ATCC BAA-2100  = JCM 16839  = KCTC 5957), FL2 ( = ATCC BAA-2098  = DSM 23585  = JCM 16840  = KCTC 5959), GT ( = ATCC BAA-2099  = JCM 16841  = KCTC 5958), CBDB1, 195(T) ( = ATCC BAA-2266(T)  = KCTC 15142(T)) and VS are considered strains of Dehalococcoides mccartyi, with strain 195(T) as the type strain. The new class Dehalococcoidia classis nov., order Dehalococcoidales ord. nov. and family Dehalococcoidaceae fam. nov. are described to accommodate the new taxon. PMID:22544797

  17. ATP-mediated killing of intracellular mycobacteria by macrophages is a P2X(7)-dependent process inducing bacterial death by phagosome-lysosome fusion.

    PubMed

    Fairbairn, I P; Stober, C B; Kumararatne, D S; Lammas, D A

    2001-09-15

    Mycobacterium tuberculosis survives within host macrophages by actively inhibiting phagosome fusion with lysosomes. Treatment of infected macrophages with ATP induces both cell apoptosis and rapid killing of intracellular mycobacteria. The following studies were undertaken to characterize the effector pathway(s) involved. Macrophages were obtained from p47(phox) and inducible NO synthase gene-disrupted mice (which are unable to produce reactive oxygen and nitrogen radicals, respectively) and P2X(7) gene-disrupted mice. RAW murine macrophages transfected with either the natural resistance-associated macrophage protein gene 1 (Nramp1)-resistant or Nramp1-susceptible gene were also used. The cells were infected with bacille Calmette-Guérin (BCG), and intracellular mycobacterial trafficking was analyzed using confocal and electron microscopy. P2X(7) receptor activation was essential for effective ATP-induced mycobacterial killing, as its bactericidal activity was radically diminished in P2X(7)(-/-) macrophages. ATP-mediated killing of BCG within p47(phox-/-), inducible NO synthase(-/-), and Nramp(s) cells was unaffected, demonstrating that none of these mechanisms have a role in the ATP/P2X(7) effector pathway. Following ATP stimulation, BCG-containing phagosomes rapidly coalesce and fuse with lysosomes. Blocking of macrophage phospholipase D activity with butan-1-ol blocked BCG killing, but not macrophage death. ATP stimulates phagosome-lysosome fusion with concomitant mycobacterial death via P2X(7) receptor activation. Macrophage death and mycobacterial killing induced by the ATP/P2X(7) signaling pathway can be uncoupled, and diverge proximal to phospholipase D activation. PMID:11544318

  18. Intracellular trafficking.

    PubMed Central

    Grant, Barth D; Sato, Miyuki

    2006-01-01

    Studies in C. elegans have begun to reveal new components and new mechanisms associated with intracellular membrane traffic in a variety of cell types. The worm benefits from many of the advantages of yeast as a genetically tractable organism for these kinds of studies while offering the unique opportunity to probe how these pathways have been extended and modified in the context of a multicellular animal undergoing development to produce diverse cell types such as muscles, nerves, and polarized epithelia. This review summarizes recent work elucidating endocytic pathways, primarily in the worm germ line and coelomocytes, and also touches on diverse studies of secretion, especially in ectodermal cells of epithelial character. PMID:18050485

  19. Intracellular microlasers

    NASA Astrophysics Data System (ADS)

    Humar, Matjaž; Hyun Yun, Seok

    2015-09-01

    Optical microresonators, which confine light within a small cavity, are widely exploited for various applications ranging from the realization of lasers and nonlinear devices to biochemical and optomechanical sensing. Here we use microresonators and suitable optical gain materials inside biological cells to demonstrate various optical functions in vitro including lasing. We explore two distinct types of microresonator—soft and hard—that support whispering-gallery modes. Soft droplets formed by injecting oil or using natural lipid droplets support intracellular laser action. The laser spectra from oil-droplet microlasers can chart cytoplasmic internal stress (˜500 pN μm-2) and its dynamic fluctuations at a sensitivity of 20 pN μm-2 (20 Pa). In a second form, whispering-gallery modes within phagocytized polystyrene beads of different sizes enable individual tagging of thousands of cells easily and, in principle, a much larger number by multiplexing with different dyes.

  20. Intracellular Biosynthesis of Fluorescent CdSe Quantum Dots in Bacillus subtilis: A Strategy to Construct Signaling Bacterial Probes for Visually Detecting Interaction Between Bacillus subtilis and Staphylococcus aureus.

    PubMed

    Yan, Zheng-Yu; Ai, Xiao-Xia; Su, Yi-Long; Liu, Xin-Ying; Shan, Xiao-Hui; Wu, Sheng-Mei

    2016-02-01

    In this work, fluorescent Bacillus subtilis (B. subtilis) cells were developed as probes for imaging applications and to explore behaviorial interaction between B. subtilis and Staphylococcus aureus (S. aureus). A novel biological strategy of coupling intracellular biochemical reactions for controllable biosynthesis of CdSe quantum dots by living B. subtilis cells was demonstrated, through which highly luminant and photostable fluorescent B. subtilis cells were achieved with good uniformity. With the help of the obtained fluorescent B. subtilis cells probes, S. aureus cells responded to co-cultured B. subtilis and to aggregate. The degree of aggregation was calculated and nonlinearly fitted to a polynomial model. Systematic investigations of their interactions implied that B. subtilis cells inhibit the growth of neighboring S. aureus cells, and this inhibition was affected by both the growth stage and the amount of surrounding B. subtilis cells. Compared to traditional methods of studying bacterial interaction between two species, such as solid culture medium colony observation and imaging mass spectrometry detection, the procedures were more simple, vivid, and photostable due to the efficient fluorescence intralabeling with less influence on the cells' surface, which might provide a new paradigm for future visualization of microbial behavior. PMID:26687198

  1. Intracellular microlasers

    PubMed Central

    Humar, Matjaž; Yun, Seok Hyun

    2015-01-01

    Optical microresonators1 which confine light within a small cavity are widely exploited for various applications ranging from the realization of lasers2 and nonlinear devices3, 4, 5 to biochemical and optomechanical sensing6, 7, 8, 9, 10, 11. Here we employ microresonators and suitable optical gain materials inside biological cells to demonstrate various optical functions in vitro including lasing. We explored two distinct types of microresonators: soft and hard, that support whispering-gallery modes (WGM). Soft droplets formed by injecting oil or using natural lipid droplets support intracellular laser action. The laser spectra from oil-droplet microlasers can chart cytoplasmic internal stress (~500 pN/μm2) and its dynamic fluctuations at a sensitivity of 20 pN/μm2 (20 Pa). In a second form, WGMs within phagocytized polystyrene beads of different sizes enable individual tagging of thousands of cells easily and, in principle, a much larger number by multiplexing with different dyes. PMID:26417383

  2. Lay obligations in professional relations.

    PubMed

    Benjamin, M

    1985-02-01

    Little has been written recently about the obligations of lay people in professional relationships. Yet the Code of Medical Ethics adopted by the American Medical Association in 1847 included an extensive statement on "Obligations of patients to their physicians'. After critically examining the philosophical foundations of this statement, I provide an alternative account of lay obligations in professional relationships. Based on a hypothetical social contract and included in a full specification of professional as well as lay obligations, this account requires lay people to honor commitments and disclose relevant information. Ethically, the account assumes that all parties in lay-professional relationships should be given equal consideration and respect in determining rights and obligations. Factually, it assumes that the treatment of many illnesses and injuries required collaboration and cooperation among lay persons and health professionals, that medical resources and personnel are limited, and that medicine, nursing, and related health professions, are, in MacIntyre's sense, practices. PMID:3884726

  3. The genome of the obligate endobacterium of an AM fungus reveals an interphylum network of nutritional interactions.

    PubMed

    Ghignone, Stefano; Salvioli, Alessandra; Anca, Iulia; Lumini, Erica; Ortu, Giuseppe; Petiti, Luca; Cruveiller, Stéphane; Bianciotto, Valeria; Piffanelli, Pietro; Lanfranco, Luisa; Bonfante, Paola

    2012-01-01

    As obligate symbionts of most land plants, arbuscular mycorrhizal fungi (AMF) have a crucial role in ecosystems, but to date, in the absence of genomic data, their adaptive biology remains elusive. In addition, endobacteria are found in their cytoplasm, the role of which is unknown. In order to investigate the function of the Gram-negative Candidatus Glomeribacter gigasporarum, an endobacterium of the AMF Gigaspora margarita, we sequenced its genome, leading to an ∼1.72-Mb assembly. Phylogenetic analyses placed Ca. G. gigasporarum in the Burkholderiaceae whereas metabolic network analyses clustered it with insect endobacteria. This positioning of Ca. G. gigasporarum among different bacterial classes reveals that it has undergone convergent evolution to adapt itself to intracellular lifestyle. The genome annotation of this mycorrhizal-fungal endobacterium has revealed an unexpected genetic mosaic where typical determinants of symbiotic, pathogenic and free-living bacteria are integrated in a reduced genome. Ca. G. gigasporarum is an aerobic microbe that depends on its host for carbon, phosphorus and nitrogen supply; it also expresses type II and type III secretion systems and synthesizes vitamin B12, antibiotics- and toxin-resistance molecules, which may contribute to the fungal host's ecological fitness. Ca. G. gigasporarum has an extreme dependence on its host for nutrients and energy, whereas the fungal host is itself an obligate biotroph that relies on a photosynthetic plant. Our work represents the first step towards unraveling a complex network of interphylum interactions, which is expected to have a previously unrecognized ecological impact. PMID:21866182

  4. Obligately barophilic bacterium from the Mariana trench.

    PubMed Central

    Yayanos, A A; Dietz, A S; Van Boxtel, R

    1981-01-01

    An amphipod (Hirondellea gigas) was retrieved with decompression in an insulated trap from an ocean depth of 10,476 m. Bacterial isolates were obtained from the dead and cold animal by using silica gel medium incubated at 1000 bars (1 bar = 10(5) Pa) and 2 degrees C. The isolate designated MT41 was found to be obligately barophilic and did not grow at a pressure close to that of 380 bars found at average depths of the sea. The optimal generation time of about 25 hr was at 2 degrees C and 690 bars. The generation time at 2 degrees C and 1,035 bars, a pressure close to that at the depth of origin, was about 33 hr. Among the conclusions are: (i) pressure is an important determinant of zonation along the water column of the sea; (ii) some obligately barophilic bacteria survive decompressions; (iii) the pressure of optimal growth at 2 degrees C appears to be less than the pressure at the depth of origin and may be diagnostic for the depth of origin; (iv) rates of reproduction are slow yet significant and an order of magnitude greater than previously thought; and (v) much of deep-sea microbiology may have been done with spurious deep-sea organisms due to warming of samples. Images PMID:6946468

  5. Obligately barophilic bacterium from the Mariana trench.

    PubMed

    Yayanos, A A; Dietz, A S; Van Boxtel, R

    1981-08-01

    An amphipod (Hirondellea gigas) was retrieved with decompression in an insulated trap from an ocean depth of 10,476 m. Bacterial isolates were obtained from the dead and cold animal by using silica gel medium incubated at 1000 bars (1 bar = 10(5) Pa) and 2 degrees C. The isolate designated MT41 was found to be obligately barophilic and did not grow at a pressure close to that of 380 bars found at average depths of the sea. The optimal generation time of about 25 hr was at 2 degrees C and 690 bars. The generation time at 2 degrees C and 1,035 bars, a pressure close to that at the depth of origin, was about 33 hr. Among the conclusions are: (i) pressure is an important determinant of zonation along the water column of the sea; (ii) some obligately barophilic bacteria survive decompressions; (iii) the pressure of optimal growth at 2 degrees C appears to be less than the pressure at the depth of origin and may be diagnostic for the depth of origin; (iv) rates of reproduction are slow yet significant and an order of magnitude greater than previously thought; and (v) much of deep-sea microbiology may have been done with spurious deep-sea organisms due to warming of samples. PMID:6946468

  6. Endosymbiosis In Statu Nascendi: Close Phylogenetic RelationshipBetween Obligately Endosymbiotic and Obligately Free-LivingPolynucleobacter Strains (Betaproteobacteria)

    SciTech Connect

    Vannini, Claudia; Pockl, Matthias; Petroni, Giulio; Wu, Qinglong; Lang, Elke; Stackebrandt, Erko; Schrallhammer, Martina; Richardson, PaulM.; Hahn, Martin W.

    2006-07-21

    Bacterial strains affiliated to the phylogenetically shallowsubcluster C (PnecC) of the 28 Polynucleobacter cluster, which ischaracterized by a minimal 16S rRNA gene sequence similarity of approx.98.5 percent, have been reported to occur as obligate endosymbionts of 30ciliates (Euplotes spp.), as well as to occur as free-living cells in thepelagic zone of freshwater habitats. We investigated if these two groupsof closely related bacteria represent 32 strains fundamentally differingin lifestyle, or if they simply represent different stages of afacultative endosymbiotic lifestyle. The phylogenetic analysis of 16SrRNA gene and 16S34 23S ITS sequences of five endosymbiont strains fromtwo different Euplotes species and 40 pure culture strains demonstratedhost-species-specific clustering of the endosymbiont 36 sequences withinthe PnecC subcluster. The sequences of the endosymbionts showedcharacteristics indicating an obligate endosymbiotic lifestyle.Cultivation experiments 38 revealed fundamental differences inphysiological adaptations, and determination of the genome sizesindicated a slight size reduction in endosymbiotic strains. We concludethat the 40 two groups of PnecC bacteria represent obligately free-livingand obligately endosymbiotic strains, respectively, and do not representdifferent stages of the same complex lifecycle. 42 These closely relatedstrains occupy completely separated ecological niches. To our bestknowledge, this is the closest phylogenetic relationship between obligateendosymbionts and 44 obligately free-living bacteria everrevealed.

  7. Targeting intracellular targets.

    PubMed

    Panyam, Jayanth; Labhasetwar, Vinod

    2004-07-01

    Many therapeutic agents have intracellular compartments as their site of action. Targeted delivery of these agents to their specific intracellular targets could result in enhanced therapeutic efficacy and reduced toxicity. Various carriers have been shown useful in targeted delivery of different classes of therapeutic agents. Among these carriers, biodegradable nanoparticles formulated from biocompatible polymers poly(D,L-lactide-co-glycolide) (PLGA) and polylactide (PLA) have shown the potential for sustained intracellular delivery of different therapeutic agents. In this review, we discuss different intracellular targets, barriers to intracellular delivery, mechanism and pathways of intracellular delivery, and various carriers and approaches that have been investigated for intracellular drug delivery. PMID:16305387

  8. Studies of polyamine metabolism in obligately alkalophilic Bacillus alcalophilus that grow at pH 11

    SciTech Connect

    Cheng, S.; Chen, K.Y.

    1987-05-01

    Bacillus alcalophilus, an obligately alkalophilic bacterium, grow at pH 11 with an intracellular pH greater than 9.5. Polyamines are positively charged at physiological pH, but less than 50% of polyamines will be charged at pH 9.5 and above. In view of the importance of polycationic nature of polyamines in their physiological functions, it is of interest to study the polyamine metabolism in B. alcalophilus, an unusual organism that grow at very high pH. Spermidine is the major polyamine in this organism, accounts for more than 90% of total polyamine. The level of spermidine fluctuates between 10 to 30 nmol per mg protein during growth. In contrast, putrescine and spermine levels stay constant during entire period of growth. No ornithine decarboxylase (DC) activity can be detected in B. alcalophilus under all conditions examined. When (/sup 3/H)arginine was added to the bacterial culture, the distribution of radioactivity in polyamine pool was 3% for putrescine, 94% for spermidine, and 3% for spermine, suggesting the presence of arginine pathway for polyamine biosynthesis. B. alcalophilus appears to possess a polyamine transport system that is Na/sup +/-dependent. Putrescine uptake in B. alcalophilus is sensitive to the inhibition of gramicidine S (10 ..mu..M) and valinomycin (2..mu..M).

  9. An Acanthamoeba sp. containing two phylogenetically different bacterial endosymbionts

    PubMed Central

    Heinz, Eva; Kolarov, Irina; Kästner, Christian; Toenshoff, Elena R; Wagner, Michael; Horn, Matthias

    2007-01-01

    Acanthamoebae are ubiquitous free-living amoebae and important predators of microbial communities. They frequently contain obligate intracellular bacterial symbionts, which show a worldwide distribution. All Acanthamoeba spp. described so far harboured no or only a single specific endosymbiont phylotype, and in some cases evidence for coevolution between the symbiotic bacteria and the amoeba host has been reported. In this study we have isolated and characterized an Acanthamoeba sp. (strain OEW1) showing a stable symbiotic relationship with two morphologically different endosymbionts. 16S rRNA sequence analysis assigned these symbionts to the candidate genus Procabacter (Betaproteobacteria) and the genus Parachlamydia (Chlamydiae) respectively. Fluorescence in situ hybridization and transmission electron microscopy confirmed the affiliation of the endosymbionts and showed their co-occurrence in the amoeba host cells and their intracellular location within separate compartments enclosed by host-derived membranes. Further analysis of this stable relationship should provide novel insights into the complex interactions of intracellular multiple-partner associations. PMID:17504498

  10. Bacterial-induced cell reprogramming to stem cell-like cells: new premise in host-pathogen interactions

    PubMed Central

    Hess, Samuel; Rambukkana, Anura

    2015-01-01

    Bacterial pathogens employ a myriad of strategies to alter host tissue cell functions for bacterial advantage during infection. Recent advances revealed a fusion of infection biology with stem cell biology by demonstrating developmental reprogramming of lineage committed host glial cells to progenitor/stem cell-like cells by an intracellular bacterial pathogen Mycobacterium leprae. Acquisition of migratory and immunomodulatory properties of such reprogrammed cells provides an added advantage for promoting bacterial spread. This presents a previously unseen sophistication of cell manipulation by hijacking the genomic plasticity of host cells by a human bacterial pathogen. The rationale for such extreme fate conversion of host cells may be directly linked to the exceedingly passive obligate life style of M. leprae with a degraded genome and host cell dependence for both bacterial survival and dissemination, particularly the use of host-derived stem cell-like cells as a vehicle for spreading infection without being detected by immune cells. Thus, this unexpected link between cell reprogramming and infection opens up a new premise in host-pathogen interactions. Furthermore, such bacterial ingenuity could also be harnessed for developing natural ways of reprogramming host cells for repairing damaged tissues from infection, injury and diseases. PMID:25541240

  11. 12 CFR 987.10 - Obligations of United States with respect to consolidated obligations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Obligations of United States with respect to consolidated obligations. 987.10 Section 987.10 Banks and Banking FEDERAL HOUSING FINANCE BOARD OFFICE OF FINANCE BOOK-ENTRY PROCEDURE FOR CONSOLIDATED OBLIGATIONS § 987.10 Obligations of United States...

  12. Intracellular fate of Mycobacterium avium: use of dual-label spectrofluorometry to investigate the influence of bacterial viability and opsonization on phagosomal pH and phagosome-lysosome interaction.

    PubMed

    Oh, Y K; Straubinger, R M

    1996-01-01

    Mycobacterium avium is a facultative intracellular pathogen that can survive and replicate within macrophages. We tested the hypotheses that survival mechanisms may include alteration of phagosomal pH or inhibition of phagosome-lysosome fusion. M. avium was surface labeled with N-hydroxysuccinimidyl esters of carboxyfluorescein (CF) and rhodamine (Rho) to enable measurement of the pH of individual M. avium-containing phagosomes and the interactions of bacterium-containing phagosomes with labeled secondary lysosomes. CF fluorescence is pH sensitive, whereas Rho is pH insensitive; pH can be calculated from their fluorescence ratios. Surface labeling of M. avium did not affect viability in broth cultures or within J774, a murine macrophage-like cell line. By fluorescence spectroscopy, live M. avium was exposed to an environmental pH of approximately 5.7 at 6 h after phagocytosis, whereas similarly labeled Salmonella typhimurium, zymosan A, or heat-killed M. avium encountered an environmental pH of < 5.0. Video fluorescence and laser scanning confocal microscopy gave consistent pH results and demonstrated the heterogeneity of intracellular fate early in infection. pH became more homogeneous 6 h after infection. M. avium cells were coated with immunoglobulin G (IgG) or opsonized to investigate whether phagocytosis by the corresponding receptors would alter intracellular fate. Opsonized, unopsonized, and IgG-coated M. avium cells entered compartments of similar pH. Finally, the spatial distribution of intracellular bacteria and secondary lysosomes was compared. Only 18% of live fluorescent M. avium cells colocalized with fluorescent lysosomes, while 98% of heat-killed bacteria colocalized. Thus, both inhibition of phagosome-lysosome fusion and alteration of phagosomal pH may contribute to the intracellular survival of M. avium. PMID:8557358

  13. Ehrlichia chaffeensis Exploits Host SUMOylation Pathways To Mediate Effector-Host Interactions and Promote Intracellular Survival

    PubMed Central

    Dunphy, Paige Selvy; Luo, Tian

    2014-01-01

    Ehrlichia chaffeensis is an obligately intracellular Gram-negative bacterium that selectively infects mononuclear phagocytes. We recently reported that E. chaffeensis utilizes a type 1 secretion (T1S) system to export tandem repeat protein (TRP) effectors and demonstrated that these effectors interact with a functionally diverse array of host proteins. By way of these interactions, TRP effectors modulate host cell functions; however, the molecular basis of these interactions and their roles in ehrlichial pathobiology are not well defined. In this study, we describe the first bacterial protein posttranslational modification (PTM) by the small ubiquitin-like modifier (SUMO). The E. chaffeensis T1S effector TRP120 is conjugated to SUMO at a carboxy-terminal canonical consensus SUMO conjugation motif in vitro and in human cells. In human cells, TRP120 was selectively conjugated with SUMO2/3 isoforms. Disruption of TRP120 SUMOylation perturbed interactions with known host proteins, through predicted SUMO interaction motif-dependent and -independent mechanisms. E. chaffeensis infection did not result in dramatic changes in the global host SUMOylated protein profile, but a robust colocalization of predominately SUMO1 with ehrlichial inclusions was observed. Inhibiting the SUMO pathway with a small-molecule inhibitor had a significant impact on E. chaffeensis replication and recruitment of the TRP120-interacting protein polycomb group ring finger protein 5 (PCGF5) to the inclusion, indicating that the SUMO pathway is critical for intracellular survival. This study reveals the novel exploitation of the SUMO pathway by Ehrlichia, which facilitates effector-eukaryote interactions necessary to usurp the host and create a permissive intracellular niche. PMID:25047847

  14. Genome sequence of Blochmannia pennsylvanicus indicates parallel evolutionary trends among bacterial mutualists of insects

    PubMed Central

    Degnan, Patrick H.; Lazarus, Adam B.; Wernegreen, Jennifer J.

    2005-01-01

    The distinct lifestyle of obligately intracellular bacteria can alter fundamental forces that drive and constrain genome change. In this study, sequencing the 792-kb genome of Blochmannia pennsylvanicus, an obligate endosymbiont of Camponotus pennsylvanicus, enabled us to trace evolutionary changes that occurred in the context of a bacterial–ant association. Comparison to the genome of Blochmannia floridanus reveals differential loss of genes involved in cofactor biosynthesis, the composition and structure of the cell wall and membrane, gene regulation, and DNA replication. However, the two Blochmannia species show complete conservation in the order and strand orientation of shared genes. This finding of extreme stasis in genome architecture, also reported previously for the aphid endosymbiont Buchnera, suggests that genome stability characterizes long-term bacterial mutualists of insects and constrains their evolutionary potential. Genome-wide analyses of protein divergences reveal 10- to 50-fold faster amino acid substitution rates in Blochmannia compared to related bacteria. Despite these varying features of genome evolution, a striking correlation in the relative divergences of proteins indicates parallel functional constraints on gene functions across ecologically distinct bacterial groups. Furthermore, the increased rates of amino acid substitution and gene loss in Blochmannia have occurred in a lineage-specific fashion, which may reflect life history differences of their ant hosts. PMID:16077009

  15. Can’t Take the Heat: High Temperature Depletes Bacterial Endosymbionts of Ants

    PubMed Central

    Fan, Yongliang; Wernegreen, Jennifer J.

    2014-01-01

    Members of the ant tribe Camponotini have coevolved with Blochmannia, an obligate intracellular bacterial mutualist. This endosymbiont lives within host bacteriocyte cells that line the ant midgut, undergoes maternal transmission from host queens to offspring, and contributes to host nutrition via nitrogen recycling and nutrient biosynthesis. While elevated temperature has been shown to disrupt obligate bacterial mutualists of some insects, its impact on the ant-Blochmannia partnership is less clear. Here, we test the effect of heat on the density of Blochmannia in two related Camponotus species in the lab. Transcriptionally active Blochmannia were quantified using RT-qPCR as the ratio of Blochmannia 16S rRNA to ant host elongation factor 1-α transcripts. Our results showed that 4 weeks of heat treatment depleted active Blochmannia by >99 % in minor workers and unmated queens. However, complete elimination of Blochmannia transcripts rarely occurred, even after 16 weeks of heat treatment. Possible mechanisms of observed thermal sensitivity may include extreme AT-richness and related features of Blochmannia genomes, as well as host stress responses. Broadly, the observed depletion of an essential microbial mutualist in heat-treated ants is analogous to the loss of zooanthellae during coral bleaching. While the ecological relevance of Blochmannia’s thermal sensitivity is uncertain, our results argue that symbiont dynamics should be part of models predicting how ants and other animals will respond and adapt to a warming climate. PMID:23872930

  16. Strategies for Intracellular Survival of Burkholderia pseudomallei

    PubMed Central

    Allwood, Elizabeth M.; Devenish, Rodney J.; Prescott, Mark; Adler, Ben; Boyce, John D.

    2011-01-01

    Burkholderia pseudomallei is the causative agent of melioidosis, a disease with high mortality that is prevalent in tropical regions of the world. A key component of the pathogenesis of melioidosis is the ability of B. pseudomallei to enter, survive, and replicate within mammalian host cells. For non-phagocytic cells, bacterial adhesins have been identified both on the bacterial surface and associated with Type 4 pili. Cell invasion involves components of one or more of the three Type 3 Secretion System clusters, which also mediate, at least in part, the escape of bacteria from the endosome into the cytoplasm, where bacteria move by actin-based motility. The mechanism of actin-based motility is not clearly understood, but appears to differ from characterized mechanisms in other bacterial species. A small proportion of intracellular bacteria is targeted by host cell autophagy, involving direct recruitment of LC3 to endosomes rather than through uptake by canonical autophagosomes. However, the majority of bacterial cells are able to circumvent autophagy and other intracellular defense mechanisms such as the induction of inducible nitric oxide synthase, and then replicate in the cytoplasm and spread to adjacent cells via membrane fusion, resulting in the formation of multi-nucleated giant cells. A potential role for host cell ubiquitin in the autophagic response to bacterial infection has recently been proposed. PMID:22007185

  17. The role of autophagy in intracellular pathogen nutrient acquisition

    PubMed Central

    Steele, Shaun; Brunton, Jason; Kawula, Thomas

    2015-01-01

    Following entry into host cells intracellular pathogens must simultaneously evade innate host defense mechanisms and acquire energy and anabolic substrates from the nutrient-limited intracellular environment. Most of the potential intracellular nutrient sources are stored within complex macromolecules that are not immediately accessible by intracellular pathogens. To obtain nutrients for proliferation, intracellular pathogens must compete with the host cell for newly-imported simple nutrients or degrade host nutrient storage structures into their constituent components (fatty acids, carbohydrates, and amino acids). It is becoming increasingly evident that intracellular pathogens have evolved a wide variety of strategies to accomplish this task. One recurrent microbial strategy is to exploit host degradative processes that break down host macromolecules into simple nutrients that the microbe can use. Herein we focus on how a subset of bacterial, viral, and eukaryotic pathogens leverage the host process of autophagy to acquire nutrients that support their growth within infected cells. PMID:26106587

  18. Cell-cycle progress in obligate predatory bacteria is dependent upon sequential sensing of prey recognition and prey quality cues.

    PubMed

    Rotem, Or; Pasternak, Zohar; Shimoni, Eyal; Belausov, Eduard; Porat, Ziv; Pietrokovski, Shmuel; Jurkevitch, Edouard

    2015-11-01

    Predators feed on prey to acquire the nutrients necessary to sustain their survival, growth, and replication. In Bdellovibrio bacteriovorus, an obligate predator of Gram-negative bacteria, cell growth and replication are tied to a shift from a motile, free-living phase of search and attack to a sessile, intracellular phase of growth and replication during which a single prey cell is consumed. Engagement and sustenance of growth are achieved through the sensing of two unidentified prey-derived cues. We developed a novel ex vivo cultivation system for B. bacteriovorus composed of prey ghost cells that are recognized and invaded by the predator. By manipulating their content, we demonstrated that an early cue is located in the prey envelope and a late cue is found within the prey soluble fraction. These spatially and temporally separated cues elicit discrete and combinatory regulatory effects on gene transcription. Together, they delimit a poorly characterized transitory phase between the attack phase and the growth phase, during which the bdelloplast (the invaded prey cell) is constructed. This transitory phase constitutes a checkpoint in which the late cue presumably acts as a determinant of the prey's nutritional value before the predator commits. These regulatory adaptations to a unique bacterial lifestyle have not been reported previously. PMID:26487679

  19. Cell-cycle progress in obligate predatory bacteria is dependent upon sequential sensing of prey recognition and prey quality cues

    PubMed Central

    Rotem, Or; Pasternak, Zohar; Shimoni, Eyal; Belausov, Eduard; Porat, Ziv; Pietrokovski, Shmuel; Jurkevitch, Edouard

    2015-01-01

    Predators feed on prey to acquire the nutrients necessary to sustain their survival, growth, and replication. In Bdellovibrio bacteriovorus, an obligate predator of Gram-negative bacteria, cell growth and replication are tied to a shift from a motile, free-living phase of search and attack to a sessile, intracellular phase of growth and replication during which a single prey cell is consumed. Engagement and sustenance of growth are achieved through the sensing of two unidentified prey-derived cues. We developed a novel ex vivo cultivation system for B. bacteriovorus composed of prey ghost cells that are recognized and invaded by the predator. By manipulating their content, we demonstrated that an early cue is located in the prey envelope and a late cue is found within the prey soluble fraction. These spatially and temporally separated cues elicit discrete and combinatory regulatory effects on gene transcription. Together, they delimit a poorly characterized transitory phase between the attack phase and the growth phase, during which the bdelloplast (the invaded prey cell) is constructed. This transitory phase constitutes a checkpoint in which the late cue presumably acts as a determinant of the prey’s nutritional value before the predator commits. These regulatory adaptations to a unique bacterial lifestyle have not been reported previously. PMID:26487679

  20. Intracellular Parasite Invasion Strategies

    NASA Astrophysics Data System (ADS)

    Sibley, L. D.

    2004-04-01

    Intracellular parasites use various strategies to invade cells and to subvert cellular signaling pathways and, thus, to gain a foothold against host defenses. Efficient cell entry, ability to exploit intracellular niches, and persistence make these parasites treacherous pathogens. Most intracellular parasites gain entry via host-mediated processes, but apicomplexans use a system of adhesion-based motility called ``gliding'' to actively penetrate host cells. Actin polymerization-dependent motility facilitates parasite migration across cellular barriers, enables dissemination within tissues, and powers invasion of host cells. Efficient invasion has brought widespread success to this group, which includes Toxoplasma, Plasmodium, and Cryptosporidium.

  1. The Olive Fly Endosymbiont, “Candidatus Erwinia dacicola,” Switches from an Intracellular Existence to an Extracellular Existence during Host Insect Development▿ †

    PubMed Central

    Estes, Anne M.; Hearn, David J.; Bronstein, Judith L.; Pierson, Elizabeth A.

    2009-01-01

    As polyphagous, holometabolous insects, tephritid fruit flies (Diptera: Tephritidae) provide a unique habitat for endosymbiotic bacteria, especially those microbes associated with the digestive system. Here we examine the endosymbiont of the olive fly [Bactrocera oleae (Rossi) (Diptera: Tephritidae)], a tephritid of great economic importance. “Candidatus Erwinia dacicola” was found in the digestive systems of all life stages of wild olive flies from the southwestern United States. PCR and microscopy demonstrated that “Ca. Erwinia dacicola” resided intracellularly in the gastric ceca of the larval midgut but extracellularly in the lumen of the foregut and ovipositor diverticulum of adult flies. “Ca. Erwinia dacicola” is one of the few nonpathogenic endosymbionts that transitions between intracellular and extracellular lifestyles during specific stages of the host's life cycle. Another unique feature of the olive fly endosymbiont is that unlike obligate endosymbionts of monophagous insects, “Ca. Erwinia dacicola” has a G+C nucleotide composition similar to those of closely related plant-pathogenic and free-living bacteria. These two characteristics of “Ca. Erwinia dacicola,” the ability to transition between intracellular and extracellular lifestyles and a G+C nucleotide composition similar to those of free-living relatives, may facilitate survival in a changing environment during the development of a polyphagous, holometabolous host. We propose that insect-bacterial symbioses should be classified based on the environment that the host provides to the endosymbiont (the endosymbiont environment). PMID:19767463

  2. Real-Time Molecular Monitoring of Chemical Environment in ObligateAnaerobes during Oxygen Adaptive Response

    SciTech Connect

    Holman, Hoi-Ying N.; Wozei, Eleanor; Lin, Zhang; Comolli, Luis R.; Ball, David. A.; Borglin, Sharon; Fields, Matthew W.; Hazen, Terry C.; Downing, Kenneth H.

    2009-02-25

    Determining the transient chemical properties of the intracellular environment canelucidate the paths through which a biological system adapts to changes in its environment, for example, the mechanisms which enable some obligate anaerobic bacteria to survive a sudden exposure to oxygen. Here we used high-resolution Fourier Transform Infrared (FTIR) spectromicroscopy to continuously follow cellular chemistry within living obligate anaerobes by monitoring hydrogen bonding in their cellular water. We observed a sequence of wellorchestrated molecular events that correspond to changes in cellular processes in those cells that survive, but only accumulation of radicals in those that do not. We thereby can interpret the adaptive response in terms of transient intracellular chemistry and link it to oxygen stress and survival. This ability to monitor chemical changes at the molecular level can yield important insights into a wide range of adaptive responses.

  3. Collectivizing rescue obligations in bioethics.

    PubMed

    Garrett, Jeremy R

    2015-01-01

    Bioethicists invoke a duty to rescue in a wide range of cases. Indeed, arguably, there exists an entire medical paradigm whereby vast numbers of medical encounters are treated as rescue cases. The intuitive power of the rescue paradigm is considerable, but much of this power stems from the problematic way that rescue cases are conceptualized-namely, as random, unanticipated, unavoidable, interpersonal events for which context is irrelevant and beneficence is the paramount value. In this article, I critique the basic assumptions of the rescue paradigm, reframe the ethical landscape in which rescue obligations are understood, and defend the necessity and value of a wider social and institutional view. Along the way, I move back and forth between ethical theory and a concrete case where the duty to rescue has been problematically applied: the purported duty to regularly return incidental findings and individual research results in genomic and genetic research. PMID:25674948

  4. Bacterial DNA Sifted from the Trichoplax adhaerens (Animalia: Placozoa) Genome Project Reveals a Putative Rickettsial Endosymbiont

    PubMed Central

    Driscoll, Timothy; Gillespie, Joseph J.; Nordberg, Eric K.; Azad, Abdu F.; Sobral, Bruno W.

    2013-01-01

    Eukaryotic genome sequencing projects often yield bacterial DNA sequences, data typically considered as microbial contamination. However, these sequences may also indicate either symbiont genes or lateral gene transfer (LGT) to host genomes. These bacterial sequences can provide clues about eukaryote–microbe interactions. Here, we used the genome of the primitive animal Trichoplax adhaerens (Metazoa: Placozoa), which is known to harbor an uncharacterized Gram-negative endosymbiont, to search for the presence of bacterial DNA sequences. Bioinformatic and phylogenomic analyses of extracted data from the genome assembly (181 bacterial coding sequences [CDS]) and trace read archive (16S rDNA) revealed a dominant proteobacterial profile strongly skewed to Rickettsiales (Alphaproteobacteria) genomes. By way of phylogenetic analysis of 16S rDNA and 113 proteins conserved across proteobacterial genomes, as well as identification of 27 rickettsial signature genes, we propose a Rickettsiales endosymbiont of T. adhaerens (RETA). The majority (93%) of the identified bacterial CDS belongs to small scaffolds containing prokaryotic-like genes; however, 12 CDS were identified on large scaffolds comprised of eukaryotic-like genes, suggesting that T. adhaerens might have recently acquired bacterial genes. These putative LGTs may coincide with the placozoan’s aquatic niche and symbiosis with RETA. This work underscores the rich, and relatively untapped, resource of eukaryotic genome projects for harboring data pertinent to host–microbial interactions. The nature of unknown (or poorly characterized) bacterial species may only emerge via analysis of host genome sequencing projects, particularly if these species are resistant to cell culturing, as are many obligate intracellular microbes. Our work provides methodological insight for such an approach. PMID:23475938

  5. 38 CFR 17.607 - Obligated service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Obligated service. 17.607 Section 17.607 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Va Health Professional Scholarship Program § 17.607 Obligated service. (a) General. Except as provided in paragraph (d) of this section, each...

  6. 43 CFR 3104.1 - Bond obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Bond obligations. 3104.1 Section 3104.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Bonds § 3104.1 Bond obligations. (a..., operating rights owner (sublessee), or operator shall submit a surety or a personal bond, conditioned...

  7. 43 CFR 3104.1 - Bond obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Bond obligations. 3104.1 Section 3104.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Bonds § 3104.1 Bond obligations. (a..., operating rights owner (sublessee), or operator shall submit a surety or a personal bond, conditioned...

  8. 43 CFR 3104.1 - Bond obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Bond obligations. 3104.1 Section 3104.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Bonds § 3104.1 Bond obligations. (a..., operating rights owner (sublessee), or operator shall submit a surety or a personal bond, conditioned...

  9. 43 CFR 3104.1 - Bond obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Bond obligations. 3104.1 Section 3104.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Bonds § 3104.1 Bond obligations. (a..., operating rights owner (sublessee), or operator shall submit a surety or a personal bond, conditioned...

  10. 5 CFR 352.908 - Agency obligation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Agency obligation. 352.908 Section 352.908 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights After Service With the Panama Canal Commission § 352.908 Agency obligation....

  11. 5 CFR 352.908 - Agency obligation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Agency obligation. 352.908 Section 352.908 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights After Service With the Panama Canal Commission § 352.908 Agency obligation....

  12. 5 CFR 352.908 - Agency obligation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Agency obligation. 352.908 Section 352.908 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights After Service With the Panama Canal Commission § 352.908 Agency obligation....

  13. 5 CFR 352.908 - Agency obligation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Agency obligation. 352.908 Section 352.908 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights After Service With the Panama Canal Commission § 352.908 Agency obligation....

  14. 5 CFR 352.908 - Agency obligation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Agency obligation. 352.908 Section 352.908 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights After Service With the Panama Canal Commission § 352.908 Agency obligation. (a) Time limits. An employee is to be...

  15. 5 CFR 724.203 - Training obligations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Training obligations. 724.203 Section 724... RETALIATION ACT OF 2002 Notification of Rights and Protections and Training § 724.203 Training obligations. (a) Each agency must develop a written plan to train all of its employees (including supervisors...

  16. 17 CFR 200.54 - Constitutional obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Constitutional obligations. 200.54 Section 200.54 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Canons of Ethics § 200.54 Constitutional obligations. The members of this Commission...

  17. 17 CFR 200.55 - Statutory obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Statutory obligations. 200.55 Section 200.55 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Canons of Ethics § 200.55 Statutory obligations. In administering the law, members of this...

  18. 47 CFR 27.1340 - Reporting obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Reporting obligations. 27.1340 Section 27.1340 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1340 Reporting obligations. (a) The Upper 700...

  19. 48 CFR 519.7013 - Obligation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Obligation. 519.7013 Section 519.7013 Federal Acquisition Regulations System GENERAL SERVICES ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS GSA Mentor-Protégé Program 519.7013 Obligation. (a) The mentor or protégé may terminate the Agreement in...

  20. 47 CFR 7.5 - General Obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false General Obligations. 7.5 Section 7.5 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO VOICEMAIL AND INTERACTIVE MENU SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Obligations-What Must Covered Entities Do? § 7.5 General...

  1. 47 CFR 7.5 - General Obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false General Obligations. 7.5 Section 7.5 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO VOICEMAIL AND INTERACTIVE MENU SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Obligations-What Must Covered Entities Do? § 7.5 General...

  2. 47 CFR 7.5 - General Obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false General Obligations. 7.5 Section 7.5 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO VOICEMAIL AND INTERACTIVE MENU SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Obligations-What Must Covered Entities Do? § 7.5 General...

  3. 47 CFR 7.5 - General Obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false General Obligations. 7.5 Section 7.5 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO VOICEMAIL AND INTERACTIVE MENU SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Obligations-What Must Covered Entities Do? § 7.5 General...

  4. 47 CFR 7.5 - General Obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false General Obligations. 7.5 Section 7.5 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO VOICEMAIL AND INTERACTIVE MENU SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Obligations-What Must Covered Entities Do? § 7.5 General...

  5. 17 CFR 200.55 - Statutory obligations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Statutory obligations. 200.55 Section 200.55 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Canons of Ethics § 200.55 Statutory obligations....

  6. 17 CFR 200.55 - Statutory obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 3 2014-04-01 2014-04-01 false Statutory obligations. 200.55 Section 200.55 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Canons of Ethics § 200.55 Statutory obligations....

  7. 17 CFR 200.55 - Statutory obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 2 2013-04-01 2013-04-01 false Statutory obligations. 200.55 Section 200.55 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Canons of Ethics § 200.55 Statutory obligations....

  8. Antibody- and TRIM21-dependent intracellular restriction of Salmonella enterica.

    PubMed

    Rakebrandt, Nikolas; Lentes, Sabine; Neumann, Heinz; James, Leo C; Neumann-Staubitz, Petra

    2014-11-01

    TRIM21 ('tripartite motif-containing protein 21', Ro52) is a ubiquitously expressed cytosolic Fc receptor, which has a potent role in protective immunity against nonenveloped viruses. TRIM21 mediates intracellular neutralisation of antibody-coated viruses, a process called ADIN (antibody-dependent intracellular neutralisation). Our results reveal a similar mechanism to fight bacterial infections. TRIM21 is recruited to the intracellular pathogen Salmonella enterica in epithelial cells early in infection. TRIM21 does not bind directly to S. enterica, but to antibodies opsonising it. Most importantly, bacterial restriction is dependent on TRIM21 as well as on the opsonisation state of the bacteria. Finally, Salmonella and TRIM21 colocalise with the autophagosomal marker LC3, and intracellular defence is enhanced in starved cells suggesting an involvement of the autophagocytic pathway. Our data extend the protective role of TRIM21 from viruses to bacteria and thereby strengthening the general role of ADIN in cellular immunity. PMID:24920099

  9. Toward Intracellular Targeted Delivery of Cancer Therapeutics

    PubMed Central

    Pandya, Hetal; Debinski, Waldemar

    2013-01-01

    A number of anti-cancer drugs have their targets localized to particular intracellular compartments. These drugs reach the targets mainly through diffusion, dependent on biophysical and biochemical forces that allow cell penetration. This means that both cancer cells and normal cells will be subjected to such diffusion; hence many of these drugs, like chemotherapeutics, are potentially toxic and the concentration achieved at the site of their action is often suboptimal. The same relates to radiation that indiscriminately affects normal and diseased cells. However, nature-designed systems enable compounds present in the extracellular environment to end up inside the cell and even travel to more specific intracellular compartments. For example, viruses and bacterial toxins can more or less specifically recognize eukaryotic cells, enter these cells, and direct some protein portions to designated intracellular areas. These phenomena have led to creative thinking, such as employing viruses or bacterial toxins for cargo delivery to cells and, more specifically, to cancer cells. Proteins can be genetically engineered in order to not only mimic what viruses and bacterial toxins can do, but also to add new functions, extending or changing the intracellular routes. It is possible to make conjugates or, more preferably, single-chain proteins that recognize cancer cells and deliver cargo inside the cells, even to the desired subcellular compartment. These findings offer new opportunities to deliver drugs/labels only to cancer cells and only to their site of action within the cells. The development of such dual-specificity vectors for targeting cancer cells is an attractive and potentially safer and more efficacious way of delivering drugs. We provide examples of this approach for delivering brain cancer therapeutics, using a specific biomarker on glioblastoma tumor cells. PMID:22671766

  10. Detection of a novel intracellular microbiome hosted in arbuscular mycorrhizal fungi

    PubMed Central

    Desirò, Alessandro; Salvioli, Alessandra; Ngonkeu, Eddy L; Mondo, Stephen J; Epis, Sara; Faccio, Antonella; Kaech, Andres; Pawlowska, Teresa E; Bonfante, Paola

    2014-01-01

    Arbuscular mycorrhizal fungi (AMF) are important members of the plant microbiome. They are obligate biotrophs that colonize the roots of most land plants and enhance host nutrient acquisition. Many AMF themselves harbor endobacteria in their hyphae and spores. Two types of endobacteria are known in Glomeromycota: rod-shaped Gram-negative Candidatus Glomeribacter gigasporarum, CaGg, limited in distribution to members of the Gigasporaceae family, and coccoid Mollicutes-related endobacteria, Mre, widely distributed across different lineages of AMF. The goal of the present study is to investigate the patterns of distribution and coexistence of the two endosymbionts, CaGg and Mre, in spore samples of several strains of Gigaspora margarita. Based on previous observations, we hypothesized that some AMF could host populations of both endobacteria. To test this hypothesis, we performed an extensive investigation of both endosymbionts in G. margarita spores sampled from Cameroonian soils as well as in the Japanese G. margarita MAFF520054 isolate using different approaches (molecular phylotyping, electron microscopy, fluorescence in situ hybridization and quantitative real-time PCR). We found that a single AMF host can harbour both types of endobacteria, with Mre population being more abundant, variable and prone to recombination than the CaGg one. Both endosymbionts seem to retain their genetic and lifestyle peculiarities regardless of whether they colonize the host alone or together. These findings show for the first time that fungi support an intracellular bacterial microbiome, in which distinct types of endobacteria coexist in a single cell. PMID:24008325

  11. Detection of a novel intracellular microbiome hosted in arbuscular mycorrhizal fungi.

    PubMed

    Desirò, Alessandro; Salvioli, Alessandra; Ngonkeu, Eddy L; Mondo, Stephen J; Epis, Sara; Faccio, Antonella; Kaech, Andres; Pawlowska, Teresa E; Bonfante, Paola

    2014-02-01

    Arbuscular mycorrhizal fungi (AMF) are important members of the plant microbiome. They are obligate biotrophs that colonize the roots of most land plants and enhance host nutrient acquisition. Many AMF themselves harbor endobacteria in their hyphae and spores. Two types of endobacteria are known in Glomeromycota: rod-shaped Gram-negative Candidatus Glomeribacter gigasporarum, CaGg, limited in distribution to members of the Gigasporaceae family, and coccoid Mollicutes-related endobacteria, Mre, widely distributed across different lineages of AMF. The goal of the present study is to investigate the patterns of distribution and coexistence of the two endosymbionts, CaGg and Mre, in spore samples of several strains of Gigaspora margarita. Based on previous observations, we hypothesized that some AMF could host populations of both endobacteria. To test this hypothesis, we performed an extensive investigation of both endosymbionts in G. margarita spores sampled from Cameroonian soils as well as in the Japanese G. margarita MAFF520054 isolate using different approaches (molecular phylotyping, electron microscopy, fluorescence in situ hybridization and quantitative real-time PCR). We found that a single AMF host can harbour both types of endobacteria, with Mre population being more abundant, variable and prone to recombination than the CaGg one. Both endosymbionts seem to retain their genetic and lifestyle peculiarities regardless of whether they colonize the host alone or together. These findings show for the first time that fungi support an intracellular bacterial microbiome, in which distinct types of endobacteria coexist in a single cell. PMID:24008325

  12. Caring work, personal obligation and collective responsibility.

    PubMed

    Provis, Chris; Stack, Sue

    2004-01-01

    Studies of workers in health care and the care of older people disclose tensions that emerge partly from their conflicting obligations. They incur some obligations from the personal relationships they have with clients, but these can be at odds with organizational demands and resource constraints. One implication is the need for policies to recognize the importance of allowing workers some discretion in decison making. Another implication may be that sometimes care workers can meet their obligations to clients only by taking collective action. PMID:14763646

  13. Inhibition or killing of an intracellular pathogen by activated macrophages is abrogated by TLCK or aminophylline.

    PubMed Central

    McLeod, R; Remington, J S

    1980-01-01

    Agents that are known to inhibit certain metabolic pathways or cell functions were evaluated to determine their effects on the capacity of activated macrophages to inhibit or kill obligate intracellular pathogens. Tosyllysine chloromethyl ketone (TLCK) and aminophylline abrogate inhibition or killing of Toxoplasma gondii by activated macrophages. PMID:7380481

  14. Bacterial computing with engineered populations.

    PubMed

    Amos, Martyn; Axmann, Ilka Maria; Blüthgen, Nils; de la Cruz, Fernando; Jaramillo, Alfonso; Rodriguez-Paton, Alfonso; Simmel, Friedrich

    2015-07-28

    We describe strategies for the construction of bacterial computing platforms by describing a number of results from the recently completed bacterial computing with engineered populations project. In general, the implementation of such systems requires a framework containing various components such as intracellular circuits, single cell input/output and cell-cell interfacing, as well as extensive analysis. In this overview paper, we describe our approach to each of these, and suggest possible areas for future research. PMID:26078340

  15. Species-specific engagement of human nucleotide oligomerization domain 2 (NOD)2 and Toll-like receptor (TLR) signalling upon intracellular bacterial infection: role of Crohn’s associated NOD2 gene variants

    PubMed Central

    Salem, M; Seidelin, J B; Eickhardt, S; Alhede, M; Rogler, G; Nielsen, O H

    2015-01-01

    Recognition of bacterial peptidoglycan-derived muramyl-dipeptide (MDP) by nucleotide oligomerization domain 2 (NOD2) induces crucial innate immune responses. Most bacteria carry the N-acetylated form of MDP (A-MDP) in their cell membranes, whereas N-glycolyl MDP (G-MDP) is typical for mycobacteria. Experimental murine studies have reported G-MDP to have a greater NOD2-stimulating capacity than A-MDP. As NOD2 polymorphisms are associated with Crohn's disease (CD), a link has been suggested between mycobacterial infections and CD. Thus, the aim was to investigate if NOD2 responses are dependent upon type of MDP and further to determine the role of NOD2 gene variants for the bacterial recognition in CD. The response pattern to A-MDP, G-MDP, Mycobacterium segmatis (expressing mainly G-MDP) and M. segmatisΔnamH (expressing A-MDP), Listeria monocytogenes (LM) (an A-MDP-containing bacteria) and M. avium paratuberculosis (MAP) (a G-MDP-containing bacteria associated with CD) was investigated in human peripheral blood mononuclear cells (PBMCs). A-MDP and M. segmatisΔnamH induced significantly higher tumour necrosis factor (TNF)-α protein levels in healthy wild-type NOD2 PBMCs compared with G-MDP and M. segmatis. NOD2 mutations resulted in a low tumour necrosis factor (TNF)-α protein secretion following stimulation with LM. Contrary to this, TNF-α levels were unchanged upon MAP stimulation regardless of NOD2 genotype and MAP solely activated NOD2- and Toll-like receptor (TLRs)-pathway with an enhanced production of interleukin (IL)-1β and IL-10. In conclusion, the results indicate that CD-associated NOD2 deficiencies might affect the response towards a broader array of commensal and pathogenic bacteria expressing A-MDP, whereas they attenuate the role of mycobacteria in the pathogenesis of CD. PMID:25335775

  16. Species-specific engagement of human nucleotide oligomerization domain 2 (NOD)2 and Toll-like receptor (TLR) signalling upon intracellular bacterial infection: role of Crohn's associated NOD2 gene variants.

    PubMed

    Salem, M; Seidelin, J B; Eickhardt, S; Alhede, M; Rogler, G; Nielsen, O H

    2015-03-01

    Recognition of bacterial peptidoglycan-derived muramyl-dipeptide (MDP) by nucleotide oligomerization domain 2 (NOD2) induces crucial innate immune responses. Most bacteria carry the N-acetylated form of MDP (A-MDP) in their cell membranes, whereas N-glycolyl MDP (G-MDP) is typical for mycobacteria. Experimental murine studies have reported G-MDP to have a greater NOD2-stimulating capacity than A-MDP. As NOD2 polymorphisms are associated with Crohn's disease (CD), a link has been suggested between mycobacterial infections and CD. Thus, the aim was to investigate if NOD2 responses are dependent upon type of MDP and further to determine the role of NOD2 gene variants for the bacterial recognition in CD. The response pattern to A-MDP, G-MDP, Mycobacterium segmatis (expressing mainly G-MDP) and M. segmatisΔnamH (expressing A-MDP), Listeria monocytogenes (LM) (an A-MDP-containing bacteria) and M. avium paratuberculosis (MAP) (a G-MDP-containing bacteria associated with CD) was investigated in human peripheral blood mononuclear cells (PBMCs). A-MDP and M. segmatisΔnamH induced significantly higher tumour necrosis factor (TNF)-α protein levels in healthy wild-type NOD2 PBMCs compared with G-MDP and M. segmatis. NOD2 mutations resulted in a low tumour necrosis factor (TNF)-α protein secretion following stimulation with LM. Contrary to this, TNF-α levels were unchanged upon MAP stimulation regardless of NOD2 genotype and MAP solely activated NOD2- and Toll-like receptor (TLRs)-pathway with an enhanced production of interleukin (IL)-1β and IL-10. In conclusion, the results indicate that CD-associated NOD2 deficiencies might affect the response towards a broader array of commensal and pathogenic bacteria expressing A-MDP, whereas they attenuate the role of mycobacteria in the pathogenesis of CD. PMID:25335775

  17. Macrophage defense mechanisms against intracellular bacteria

    PubMed Central

    Weiss, Günter; Schaible, Ulrich E

    2015-01-01

    Macrophages and neutrophils play a decisive role in host responses to intracellular bacteria including the agent of tuberculosis (TB), Mycobacterium tuberculosis as they represent the forefront of innate immune defense against bacterial invaders. At the same time, these phagocytes are also primary targets of intracellular bacteria to be abused as host cells. Their efficacy to contain and eliminate intracellular M. tuberculosis decides whether a patient initially becomes infected or not. However, when the infection becomes chronic or even latent (as in the case of TB) despite development of specific immune activation, phagocytes have also important effector functions. Macrophages have evolved a myriad of defense strategies to combat infection with intracellular bacteria such as M. tuberculosis. These include induction of toxic anti-microbial effectors such as nitric oxide and reactive oxygen intermediates, the stimulation of microbe intoxication mechanisms via acidification or metal accumulation in the phagolysosome, the restriction of the microbe's access to essential nutrients such as iron, fatty acids, or amino acids, the production of anti-microbial peptides and cytokines, along with induction of autophagy and efferocytosis to eliminate the pathogen. On the other hand, M. tuberculosis, as a prime example of a well-adapted facultative intracellular bacterium, has learned during evolution to counter-balance the host's immune defense strategies to secure survival or multiplication within this otherwise hostile environment. This review provides an overview of innate immune defense of macrophages directed against intracellular bacteria with a focus on M. tuberculosis. Gaining more insights and knowledge into this complex network of host-pathogen interaction will identify novel target sites of intervention to successfully clear infection at a time of rapidly emerging multi-resistance of M. tuberculosis against conventional antibiotics. PMID:25703560

  18. 42 CFR 408.4 - Payment obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... kidney donors. (1) No premiums are required for SMI benefits related to the donation of a kidney if the donor is not an enrollee. (2) A kidney donor who is an enrollee is not relieved of the obligation...

  19. 42 CFR 408.4 - Payment obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... kidney donors. (1) No premiums are required for SMI benefits related to the donation of a kidney if the donor is not an enrollee. (2) A kidney donor who is an enrollee is not relieved of the obligation...

  20. 42 CFR 408.4 - Payment obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... kidney donors. (1) No premiums are required for SMI benefits related to the donation of a kidney if the donor is not an enrollee. (2) A kidney donor who is an enrollee is not relieved of the obligation...

  1. 42 CFR 408.4 - Payment obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... kidney donors. (1) No premiums are required for SMI benefits related to the donation of a kidney if the donor is not an enrollee. (2) A kidney donor who is an enrollee is not relieved of the obligation...

  2. 42 CFR 408.4 - Payment obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... kidney donors. (1) No premiums are required for SMI benefits related to the donation of a kidney if the donor is not an enrollee. (2) A kidney donor who is an enrollee is not relieved of the obligation...

  3. 46 CFR Sec. 11 - Guarantee obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 11 Guarantee obligations. (a) Under the provisions of Article 10 of the NSA-LUMPSUMREP...

  4. 46 CFR Sec. 11 - Guarantee obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 11 Guarantee obligations. (a) Under the provisions of Article 10 of the NSA-LUMPSUMREP...

  5. 46 CFR Sec. 11 - Guarantee obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 11 Guarantee obligations. (a) Under the provisions of Article 10 of the NSA-LUMPSUMREP...

  6. 46 CFR Sec. 11 - Guarantee obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 11 Guarantee obligations. (a) Under the provisions of Article 10 of the NSA-LUMPSUMREP...

  7. 46 CFR Sec. 11 - Guarantee obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 11 Guarantee obligations. (a) Under the provisions of Article 10 of the NSA-LUMPSUMREP...

  8. 30 CFR 717.11 - General obligations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... underground operations. Surface operations include construction, use, and reclamation of new and existing... construction, operation, and reclamation of shafts, adits, underground support facilities, underground mining... PROGRAM REGULATIONS UNDERGROUND MINING GENERAL PERFORMANCE STANDARDS § 717.11 General obligations....

  9. 30 CFR 717.11 - General obligations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... underground operations. Surface operations include construction, use, and reclamation of new and existing... construction, operation, and reclamation of shafts, adits, underground support facilities, underground mining... PROGRAM REGULATIONS UNDERGROUND MINING GENERAL PERFORMANCE STANDARDS § 717.11 General obligations....

  10. Bacterial gastroenteritis

    MedlinePlus

    Infectious diarrhea - bacterial gastroenteritis; Acute gastroenteritis; Gastroenteritis - bacterial ... the sickness. All types of food poisoning cause diarrhea . Other symptoms include: Abdominal cramps Abdominal pain Bloody ...

  11. Microbial minimalism: genome reduction in bacterial pathogens.

    PubMed

    Moran, Nancy A

    2002-03-01

    When bacterial lineages make the transition from free-living or facultatively parasitic life cycles to permanent associations with hosts, they undergo a major loss of genes and DNA. Complete genome sequences are providing an understanding of how extreme genome reduction affects evolutionary directions and metabolic capabilities of obligate pathogens and symbionts. PMID:11893328

  12. 46 CFR 298.30 - Nature and content of Obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Nature and content of Obligations. 298.30 Section 298.30 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VESSEL FINANCING ASSISTANCE OBLIGATION GUARANTEES Documentation § 298.30 Nature and content of Obligations. (a) Single page. An Obligation, in...

  13. 46 CFR 298.30 - Nature and content of Obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Nature and content of Obligations. 298.30 Section 298.30 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VESSEL FINANCING ASSISTANCE OBLIGATION GUARANTEES Documentation § 298.30 Nature and content of Obligations. (a) Single page. An Obligation, in...

  14. 46 CFR 298.30 - Nature and content of Obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Nature and content of Obligations. 298.30 Section 298.30 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VESSEL FINANCING ASSISTANCE OBLIGATION GUARANTEES Documentation § 298.30 Nature and content of Obligations. (a) Single page. An Obligation, in...

  15. 46 CFR 298.30 - Nature and content of Obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Nature and content of Obligations. 298.30 Section 298.30 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VESSEL FINANCING ASSISTANCE OBLIGATION GUARANTEES Documentation § 298.30 Nature and content of Obligations. (a) Single page. An Obligation, in...

  16. 46 CFR 298.30 - Nature and content of Obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Nature and content of Obligations. 298.30 Section 298.30 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VESSEL FINANCING ASSISTANCE OBLIGATION GUARANTEES Documentation § 298.30 Nature and content of Obligations. (a) Single page. An Obligation, in...

  17. Sterile-α- and armadillo motif-containing protein inhibits the TRIF-dependent downregulation of signal regulatory protein α to interfere with intracellular bacterial elimination in Burkholderia pseudomallei-infected mouse macrophages.

    PubMed

    Baral, Pankaj; Utaisincharoen, Pongsak

    2013-09-01

    Burkholderia pseudomallei, the causative agent of melioidosis, evades macrophage killing by suppressing the TRIF-dependent pathway, leading to inhibition of inducible nitric oxide synthase (iNOS) expression. We previously demonstrated that virulent wild-type B. pseudomallei inhibits the TRIF-dependent pathway by upregulating sterile-α- and armadillo motif-containing protein (SARM) and by inhibiting downregulation of signal regulatory protein α (SIRPα); both molecules are negative regulators of Toll-like receptor signaling. In contrast, the less virulent lipopolysaccharide (LPS) mutant of B. pseudomallei is unable to exhibit these features and is susceptible to macrophage killing. However, the functional relationship of these two negative regulators in the evasion of macrophage defense has not been elucidated. We demonstrated here that SIRPα downregulation was observed after inhibition of SARM expression by small interfering RNA in wild-type-infected macrophages, indicating that SIRPα downregulation is regulated by SARM. Furthermore, this downregulation requires activation of the TRIF signaling pathway, as we observed abrogation of SIRPα downregulation as well as restricted bacterial growth in LPS mutant-infected TRIF-depleted macrophages. Although inhibition of SARM expression is correlated to SIRPα downregulation and iNOS upregulation in gamma interferon-activated wild-type-infected macrophages, these phenomena appear to bypass the TRIF-dependent pathway. Similar to live bacteria, the wild-type LPS is able to upregulate SARM and to prevent SIRPα downregulation, implying that the LPS of B. pseudomallei may play a crucial role in regulating the expression of these two negative regulators. Altogether, our findings show a previously unrecognized role of B. pseudomallei-induced SARM in inhibiting SIRPα downregulation-mediated iNOS upregulation, facilitating the ability of the bacterium to multiply in macrophages. PMID:23836818

  18. Unveiling the Intracellular Survival Gene Kit of Trypanosomatid Parasites

    PubMed Central

    Bartholomeu, Daniella Castanheira; de Paiva, Rita Marcia Cardoso; Mendes, Tiago A. O.; DaRocha, Wanderson D.; Teixeira, Santuza M. R.

    2014-01-01

    Trypanosomatids are unicellular protozoans of medical and economical relevance since they are the etiologic agents of infectious diseases in humans as well as livestock. Whereas Trypanosoma cruzi and different species of Leishmania are obligate intracellular parasites, Trypanosoma brucei and other trypanosomatids develop extracellularly throughout their entire life cycle. After their genomes have been sequenced, various comparative genomic studies aimed at identifying sequences involved with host cell invasion and intracellular survival have been described. However, for only a handful of genes, most of them present exclusively in the T. cruzi or Leishmania genomes, has there been any experimental evidence associating them with intracellular parasitism. With the increasing number of published complete genome sequences of members of the trypanosomatid family, including not only different Trypanosoma and Leishmania strains and subspecies but also trypanosomatids that do not infect humans or other mammals, we may now be able to contemplate a slightly better picture regarding the specific set of parasite factors that defines each organism's mode of living and the associated disease phenotypes. Here, we review the studies concerning T. cruzi and Leishmania genes that have been implicated with cell invasion and intracellular parasitism and also summarize the wealth of new information regarding the mode of living of intracellular parasites that is resulting from comparative genome studies that are based on increasingly larger trypanosomatid genome datasets. PMID:25474314

  19. Quantification and characterization of mucosa-associated and intracellular Escherichia coli in inflamatory bowel disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background and aims: Mucosa-associated E. coli are abundant in Crohn’s disease (CD) but whether these bacteria gain intracellular access within the mucosa is less certain. If E. coli does gain intracellular access in CD, the contribution of bacterial pathogenicity as opposed to a defect in host inna...

  20. Nanovehicular Intracellular Delivery Systems

    PubMed Central

    PROKOP, ALES; DAVIDSON, JEFFREY M.

    2013-01-01

    This article provides an overview of principles and barriers relevant to intracellular drug and gene transport, accumulation and retention (collectively called as drug delivery) by means of nanovehicles (NV). The aim is to deliver a cargo to a particular intracellular site, if possible, to exert a local action. Some of the principles discussed in this article apply to noncolloidal drugs that are not permeable to the plasma membrane or to the blood–brain barrier. NV are defined as a wide range of nanosized particles leading to colloidal objects which are capable of entering cells and tissues and delivering a cargo intracelullarly. Different localization and targeting means are discussed. Limited discussion on pharmacokinetics and pharmacodynamics is also presented. NVs are contrasted to micro-delivery and current nanotechnologies which are already in commercial use. Newer developments in NV technologies are outlined and future applications are stressed. We also briefly review the existing modeling tools and approaches to quantitatively describe the behavior of targeted NV within the vascular and tumor compartments, an area of particular importance. While we list “elementary” phenomena related to different level of complexity of delivery to cancer, we also stress importance of multi-scale modeling and bottom-up systems biology approach. PMID:18200527

  1. 19 CFR 10.585 - Importer obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Importer obligations. 10.585 Section 10.585 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. Dominican Republic-Central America-United States Free Trade Agreement...

  2. 38 CFR 17.607 - Obligated service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... employee in full-time clinical practice in the participant's discipline in an assignment or location... date, or the date the participant becomes licensed in a State to practice in the discipline for which... obligated service for a participant who attended school as a full-time student shall be 1 year for...

  3. 38 CFR 17.607 - Obligated service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... employee in full-time clinical practice in the participant's discipline in an assignment or location... date, or the date the participant becomes licensed in a State to practice in the discipline for which... obligated service for a participant who attended school as a full-time student shall be 1 year for...

  4. 38 CFR 17.607 - Obligated service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... employee in full-time clinical practice in the participant's discipline in an assignment or location... date, or the date the participant becomes licensed in a State to practice in the discipline for which... obligated service for a participant who attended school as a full-time student shall be 1 year for...

  5. 47 CFR 27.1340 - Reporting obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Reporting obligations. 27.1340 Section 27.1340 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS... deployed, which public safety entities are using the broadband network in each area of operation,...

  6. Higher Education's Cultural Obligations: Views and Reviews.

    ERIC Educational Resources Information Center

    Reid, John Y., Ed.

    Perspectives on the cultural obligations of higher education are presented in this collection of papers. Higher education's possible and probable cultural function is addressed from the perspective of business, the arts, education, and religion. Also discussed is the role of institutions of higher education in establishing a system of values,…

  7. 19 CFR 10.905 - Importer obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Importer obligations. 10.905 Section 10.905 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Peru Trade...

  8. 19 CFR 10.3005 - Importer obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Importer obligations. 10.3005 Section 10.3005 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Colombia...

  9. 19 CFR 10.3005 - Importer obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Importer obligations. 10.3005 Section 10.3005 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Colombia...

  10. 47 CFR 27.1340 - Reporting obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1340 Reporting obligations. (a) The Upper 700 MHz D Block licensee and the Public Safety Broadband Licensee shall jointly file quarterly reports with... requirements of public safety are being met, detailed information on the areas where broadband service has...

  11. 47 CFR 90.1440 - Reporting obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES 700 MHz Public/Private Partnership § 90.1440 Reporting obligations. (a) The Upper 700 MHz D Block licensee and the Public Safety Broadband Licensee shall jointly file quarterly...

  12. The author’s opportunity and obligation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peer review is a critical component of the scientific method and therefore should be an obligation for everyone who desires to publish their research results in refereed journals. This editorial is written to address a specific problem being encountered by editors of Soil & Tillage Research, but the...

  13. 31 CFR 1021.311 - Filing obligations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Filing obligations. 1021.311 Section 1021.311 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FINANCIAL CRIMES ENFORCEMENT NETWORK, DEPARTMENT OF THE TREASURY RULES FOR CASINOS AND CARD CLUBS Reports Required To Be Made By Casinos and Card Clubs...

  14. 31 CFR 1021.311 - Filing obligations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Filing obligations. 1021.311 Section 1021.311 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FINANCIAL CRIMES ENFORCEMENT NETWORK, DEPARTMENT OF THE TREASURY RULES FOR CASINOS AND CARD CLUBS Reports Required To Be Made By Casinos and Card Clubs...

  15. 19 CFR 10.2005 - Importer obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Importer obligations. 10.2005 Section 10.2005 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Panama Trade...

  16. 34 CFR 108.5 - Compliance obligations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false Compliance obligations. 108.5 Section 108.5 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION EQUAL ACCESS TO PUBLIC SCHOOL FACILITIES FOR THE BOY SCOUTS OF AMERICA AND OTHER DESIGNATED YOUTH...

  17. 34 CFR 108.5 - Compliance obligations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Compliance obligations. 108.5 Section 108.5 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION EQUAL ACCESS TO PUBLIC SCHOOL FACILITIES FOR THE BOY SCOUTS OF AMERICA AND OTHER DESIGNATED YOUTH...

  18. 34 CFR 108.5 - Compliance obligations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Compliance obligations. 108.5 Section 108.5 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION EQUAL ACCESS TO PUBLIC SCHOOL FACILITIES FOR THE BOY SCOUTS OF AMERICA AND OTHER DESIGNATED YOUTH...

  19. Inability and Obligation in Moral Judgment

    PubMed Central

    Buckwalter, Wesley; Turri, John

    2015-01-01

    It is often thought that judgments about what we ought to do are limited by judgments about what we can do, or that “ought implies can.” We conducted eight experiments to test the link between a range of moral requirements and abilities in ordinary moral evaluations. Moral obligations were repeatedly attributed in tandem with inability, regardless of the type (Experiments 1–3), temporal duration (Experiment 5), or scope (Experiment 6) of inability. This pattern was consistently observed using a variety of moral vocabulary to probe moral judgments and was insensitive to different levels of seriousness for the consequences of inaction (Experiment 4). Judgments about moral obligation were no different for individuals who can or cannot perform physical actions, and these judgments differed from evaluations of a non-moral obligation (Experiment 7). Together these results demonstrate that commonsense morality rejects the “ought implies can” principle for moral requirements, and that judgments about moral obligation are made independently of considerations about ability. By contrast, judgments of blame were highly sensitive to considerations about ability (Experiment 8), which suggests that commonsense morality might accept a “blame implies can” principle. PMID:26296206

  20. 19 CFR 10.765 - Importer obligations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Importer obligations. 10.765 Section 10.765 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free...

  1. 19 CFR 10.765 - Importer obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Importer obligations. 10.765 Section 10.765 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free...

  2. 19 CFR 10.765 - Importer obligations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Importer obligations. 10.765 Section 10.765 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free...

  3. 19 CFR 10.765 - Importer obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Importer obligations. 10.765 Section 10.765 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free...

  4. 19 CFR 10.765 - Importer obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Importer obligations. 10.765 Section 10.765 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free...

  5. 7 CFR 993.56 - Reserve obligation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Reserve obligation. 993.56 Section 993.56 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... requirement as to setaside reflecting average marketable content of receipts is not essential to...

  6. 33 CFR 137.5 - Disclosure obligations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Disclosure obligations. 137.5 Section 137.5 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY: STANDARDS FOR...

  7. 33 CFR 137.5 - Disclosure obligations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Disclosure obligations. 137.5 Section 137.5 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY: STANDARDS FOR CONDUCTING ALL APPROPRIATE INQUIRIES UNDER THE...

  8. 7 CFR 987.145 - Withholding obligation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... an adequate quantity of that variety inspected and certified as meeting the applicable grade, size..., the quantity so credited shall never exceed 40 percent of the handler's withholding obligation of the... the inspection service, and in due course a copy of the on board bill of lading or other...

  9. 7 CFR 987.145 - Withholding obligation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... an adequate quantity of that variety inspected and certified as meeting the applicable grade, size..., the quantity so credited shall never exceed 40 percent of the handler's withholding obligation of the... the inspection service, and in due course a copy of the on board bill of lading or other...

  10. 7 CFR 987.145 - Withholding obligation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... an adequate quantity of that variety inspected and certified as meeting the applicable grade, size..., the quantity so credited shall never exceed 40 percent of the handler's withholding obligation of the... the inspection service, and in due course a copy of the on board bill of lading or other...

  11. 7 CFR 987.145 - Withholding obligation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... an adequate quantity of that variety inspected and certified as meeting the applicable grade, size..., the quantity so credited shall never exceed 40 percent of the handler's withholding obligation of the... the inspection service, and in due course a copy of the on board bill of lading or other...

  12. 19 CFR 10.412 - Importer obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Importer obligations. 10.412 Section 10.412 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free...

  13. 19 CFR 10.412 - Importer obligations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Importer obligations. 10.412 Section 10.412 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free...

  14. 19 CFR 10.412 - Importer obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Importer obligations. 10.412 Section 10.412 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free...

  15. 19 CFR 10.512 - Importer obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Importer obligations. 10.512 Section 10.512 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Singapore Free...

  16. 33 CFR 137.5 - Disclosure obligations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Disclosure obligations. 137.5 Section 137.5 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY: STANDARDS FOR...

  17. 33 CFR 137.5 - Disclosure obligations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Disclosure obligations. 137.5 Section 137.5 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY: STANDARDS FOR...

  18. 33 CFR 137.5 - Disclosure obligations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Disclosure obligations. 137.5 Section 137.5 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY: STANDARDS FOR...

  19. 19 CFR 10.905 - Importer obligations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Importer obligations. 10.905 Section 10.905 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Peru Trade...

  20. 19 CFR 10.905 - Importer obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Importer obligations. 10.905 Section 10.905 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Peru Trade...

  1. 5 CFR 724.103 - Agency obligations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Agency obligations. 724.103 Section 724.103 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) IMPLEMENTATION OF TITLE II OF THE NOTIFICATION AND FEDERAL EMPLOYEE ANTIDISCRIMINATION...

  2. VIEWING RESEARCH PARTICIPATION AS A MORAL OBLIGATION

    PubMed Central

    RENNIE, STUART

    2015-01-01

    A moral paradigm shift has proposed for participation in health-related research. It’s not just a praiseworthy option, some say; it’s a social obligation. Recasting research participation in this way would have global ramifications, however. Who ultimately stands to gain the most from it, and who has the most to lose? PMID:21495516

  3. 19 CFR 10.412 - Importer obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Importer obligations. 10.412 Section 10.412 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free...

  4. 19 CFR 10.412 - Importer obligations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Importer obligations. 10.412 Section 10.412 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free...

  5. 43 CFR 10005.8 - Mitigation obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Mitigation obligations. 10005.8 Section 10005.8 Public Lands: Interior Regulations Relating to Public Lands (Continued) UTAH RECLAMATION MITIGATION AND CONSERVATION COMMISSION POLICIES AND PROCEDURES FOR DEVELOPING AND IMPLEMENTING THE COMMISSION'S MITIGATION AND CONSERVATION PLAN §...

  6. 47 CFR 14.20 - Obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Obligations. 14.20 Section 14.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO ADVANCED COMMUNICATIONS SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Implementation Requirements-What Must Covered Entities Do? §...

  7. 47 CFR 14.20 - Obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Obligations. 14.20 Section 14.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO ADVANCED COMMUNICATIONS SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Implementation Requirements-What Must Covered Entities Do? §...

  8. 47 CFR 14.20 - Obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Obligations. 14.20 Section 14.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO ADVANCED COMMUNICATIONS SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Implementation Requirements-What Must Covered Entities Do? §...

  9. 17 CFR 200.54 - Constitutional obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 2 2013-04-01 2013-04-01 false Constitutional obligations. 200.54 Section 200.54 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Canons of Ethics § 200.54...

  10. 17 CFR 200.54 - Constitutional obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 3 2014-04-01 2014-04-01 false Constitutional obligations. 200.54 Section 200.54 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Canons of Ethics § 200.54...

  11. 17 CFR 200.54 - Constitutional obligations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Constitutional obligations. 200.54 Section 200.54 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Canons of Ethics § 200.54...

  12. 42 CFR 136.332 - Service obligation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Service obligation. 136.332 Section 136.332 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES INDIAN HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES INDIAN HEALTH Indian Health Care Improvement Act Programs Subdivision...

  13. The Bacterial Cytoskeleton

    PubMed Central

    Shih, Yu-Ling; Rothfield, Lawrence

    2006-01-01

    In recent years it has been shown that bacteria contain a number of cytoskeletal structures. The bacterial cytoplasmic elements include homologs of the three major types of eukaryotic cytoskeletal proteins (actin, tubulin, and intermediate filament proteins) and a fourth group, the MinD-ParA group, that appears to be unique to bacteria. The cytoskeletal structures play important roles in cell division, cell polarity, cell shape regulation, plasmid partition, and other functions. The proteins self-assemble into filamentous structures in vitro and form intracellular ordered structures in vivo. In addition, there are a number of filamentous bacterial elements that may turn out to be cytoskeletal in nature. This review attempts to summarize and integrate the in vivo and in vitro aspects of these systems and to evaluate the probable future directions of this active research field. PMID:16959967

  14. Understanding How Commensal Obligate Anaerobic Bacteria Regulate Immune Functions in the Large Intestine

    PubMed Central

    Maier, Eva; Anderson, Rachel C.; Roy, Nicole C.

    2014-01-01

    The human gastrointestinal tract is colonised by trillions of commensal bacteria, most of which are obligate anaerobes residing in the large intestine. Appropriate bacterial colonisation is generally known to be critical for human health. In particular, the development and function of the immune system depends on microbial colonisation, and a regulated cross-talk between commensal bacteria, intestinal epithelial cells and immune cells is required to maintain mucosal immune homeostasis. This homeostasis is disturbed in various inflammatory disorders, such as inflammatory bowel diseases. Several in vitro and in vivo studies indicate a role for Faecalibacterium prausnitzii, Bacteroides thetaiotaomicron, Bacteroides fragilis, Akkermansia muciniphila and segmented filamentous bacteria in maintaining intestinal immune homeostasis. These obligate anaerobes are abundant in the healthy intestine but reduced in several inflammatory diseases, suggesting an association with protective effects on human health. However, knowledge of the mechanisms underlying the effects of obligate anaerobic intestinal bacteria remains limited, in part due to the difficulty of co-culturing obligate anaerobes together with oxygen-requiring human epithelial cells. By using novel dual-environment co-culture models, it will be possible to investigate the effects of the unstudied majority of intestinal microorganisms on the human epithelia. This knowledge will provide opportunities for improving human health and reducing the risk of inflammatory diseases. PMID:25545102

  15. Bacterial Sialidase

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Data shows that elevated sialidase in bacterial vaginosis patients correlates to premature births in women. Bacterial sialidase also plays a significant role in the unusual colonization of Pseudomonas aeruginosa in cystic fibrosis patients. Crystals of Salmonella sialidase have been reproduced and are used for studying the inhibitor-enzyme complexes. These inhibitors may also be used to inhibit a trans-sialidase of Trypanosome cruzi, a very similar enzyme to bacterial sialidase, therefore preventing T. cruzi infection, the causitive agent of Chagas' disease. The Center for Macromolecular Crystallography suggests that inhibitors of bacterial sialidases can be used as prophylactic drugs to prevent bacterial infections in these critical cases.

  16. 47 CFR 64.1300 - Payphone compensation obligation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Payphone compensation obligation. 64.1300... compensation obligation. (a) For purposes of this subpart, a Completing Carrier is a long distance carrier or... parties by contract. (c) The compensation obligation set forth herein shall not apply to calls...

  17. 47 CFR 64.1300 - Payphone compensation obligation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Payphone compensation obligation. 64.1300... compensation obligation. (a) For purposes of this subpart, a Completing Carrier is a long distance carrier or... parties by contract. (c) The compensation obligation set forth herein shall not apply to calls...

  18. 47 CFR 64.1300 - Payphone compensation obligation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Payphone compensation obligation. 64.1300... compensation obligation. (a) For purposes of this subpart, a Completing Carrier is a long distance carrier or... parties by contract. (c) The compensation obligation set forth herein shall not apply to calls...

  19. 24 CFR 213.266a - Insurance fund obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... obligation either of the Cooperative Management Housing Insurance Fund or of the General Insurance Fund. The... Management Housing Insurance Fund, shall also be the obligation of the General Insurance Fund. ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Insurance fund obligations....

  20. 28 CFR 811.3 - Notice of obligation to register.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Notice of obligation to register. 811.3 Section 811.3 Judicial Administration COURT SERVICES AND OFFENDER SUPERVISION AGENCY FOR THE DISTRICT OF COLUMBIA SEX OFFENDER REGISTRATION § 811.3 Notice of obligation to register. (a) Sex offenders may be notified of their obligation to...

  1. 49 CFR 22.17 - Compliance with child support obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Compliance with child support obligations. 22.17...) Policies Applying to STLP Loans § 22.17 Compliance with child support obligations. Any holder of 50% or... than 60 days delinquent on any obligation to pay child support arising under: (a) An...

  2. 49 CFR 22.17 - Compliance with child support obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Compliance with child support obligations. 22.17...) Policies Applying to STLP Loans § 22.17 Compliance with child support obligations. Any holder of 50% or... than 60 days delinquent on any obligation to pay child support arising under: (a) An...

  3. 49 CFR 22.17 - Compliance with child support obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Compliance with child support obligations. 22.17...) Policies Applying to STLP Loans § 22.17 Compliance with child support obligations. Any holder of 50% or... than 60 days delinquent on any obligation to pay child support arising under: (a) An...

  4. 24 CFR 891.755 - Obligations of the family.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Obligations of the family. 891.755... the Elderly and Persons with Disabilities Section 202 Projects for the Nonelderly Handicapped Families and Individuals-Section 162 Assistance § 891.755 Obligations of the family. The obligations of...

  5. 24 CFR 891.615 - Obligations of the family.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Obligations of the family. 891.615 Section 891.615 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT... 8 Assistance § 891.615 Obligations of the family. The obligations of the family are provided...

  6. 24 CFR 891.755 - Obligations of the family.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Obligations of the family. 891.755... the Elderly and Persons with Disabilities Section 202 Projects for the Nonelderly Handicapped Families and Individuals-Section 162 Assistance § 891.755 Obligations of the family. The obligations of...

  7. 24 CFR 891.615 - Obligations of the family.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Obligations of the family. 891.615 Section 891.615 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT... 8 Assistance § 891.615 Obligations of the family. The obligations of the family are provided...

  8. 24 CFR 891.755 - Obligations of the family.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Obligations of the family. 891.755... the Elderly and Persons with Disabilities Section 202 Projects for the Nonelderly Handicapped Families and Individuals-Section 162 Assistance § 891.755 Obligations of the family. The obligations of...

  9. 24 CFR 891.615 - Obligations of the family.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Obligations of the family. 891.615 Section 891.615 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT... 8 Assistance § 891.615 Obligations of the family. The obligations of the family are provided...

  10. 24 CFR 891.755 - Obligations of the family.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Obligations of the family. 891.755... the Elderly and Persons with Disabilities Section 202 Projects for the Nonelderly Handicapped Families and Individuals-Section 162 Assistance § 891.755 Obligations of the family. The obligations of...

  11. 24 CFR 891.615 - Obligations of the family.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Obligations of the family. 891.615 Section 891.615 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT... 8 Assistance § 891.615 Obligations of the family. The obligations of the family are provided...

  12. 39 CFR 931.1 - Compromise of obligations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Compromise of obligations. 931.1 Section 931.1 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PROCEDURE GOVERNING THE COMPROMISE OF OBLIGATIONS § 931.1 Compromise of obligations. Any proposition of compromise shall be submitted in writing, and the amount offered in compromise...

  13. 31 CFR 225.5 - Pledge of definitive Government obligations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Government obligations to the bond official with all unmatured interest coupons attached. (2) Registered...) Delivery to bond official; receipt. All deliveries of definitive Government obligations from the obligor to... of definitive Government obligations, the bond official will issue the obligor a receipt. (c) Risk...

  14. 24 CFR 891.755 - Obligations of the family.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Obligations of the family. 891.755... the Elderly and Persons with Disabilities Section 202 Projects for the Nonelderly Handicapped Families and Individuals-Section 162 Assistance § 891.755 Obligations of the family. The obligations of...

  15. 24 CFR 891.615 - Obligations of the family.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Obligations of the family. 891.615 Section 891.615 Housing and Urban Development Regulations Relating to Housing and Urban Development... 8 Assistance § 891.615 Obligations of the family. The obligations of the family are provided...

  16. 31 CFR 149.3 - Maximum obligation limitation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Maximum obligation limitation. 149.3 Section 149.3 Money and Finance: Treasury Regulations Relating to Money and Finance MONETARY OFFICES, DEPARTMENT OF THE TREASURY CALCULATION OF MAXIMUM OBLIGATION LIMITATION § 149.3 Maximum obligation...

  17. 49 CFR 22.17 - Compliance with child support obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Compliance with child support obligations. 22.17...) Policies Applying to STLP Loans § 22.17 Compliance with child support obligations. Any holder of 50% or... than 60 days delinquent on any obligation to pay child support arising under: (a) An...

  18. 49 CFR 22.17 - Compliance with child support obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Compliance with child support obligations. 22.17...) Policies Applying to STLP Loans § 22.17 Compliance with child support obligations. Any holder of 50% or... than 60 days delinquent on any obligation to pay child support arising under: (a) An...

  19. A New Role of the Complement System: C3 Provides Protection in a Mouse Model of Lung Infection with Intracellular Chlamydia psittaci

    PubMed Central

    Bode, Jenny; Dutow, Pavel; Sommer, Kirsten; Janik, Katrin; Glage, Silke; Tümmler, Burkhard; Munder, Antje; Laudeley, Robert; Sachse, Konrad W.; Klos, Andreas

    2012-01-01

    The complement system modulates the intensity of innate and specific immunity. While it protects against infections by extracellular bacteria its role in infection with obligate intracellular bacteria, such as the avian and human pathogen Chlamydia (C.) psittaci, is still unknown. In the present study, knockout mice lacking C3 and thus all main complement effector functions were intranasally infected with C. psittaci strain DC15. Clinical parameters, lung histology, and cytokine levels were determined. A subset of infections was additionally performed with mice lacking C5 or C5a receptors. Complement activation occurred before symptoms of pneumonia appeared. Mice lacking C3 were ∼100 times more susceptible to the intracellular bacteria compared to wild-type mice, with all C3−/− mice succumbing to infection after day 9. At a low infective dose, C3−/− mice became severely ill after an even longer delay, the kinetics suggesting a so far unknown link of complement to the adaptive, protective immune response against chlamydiae. The lethal phenotype of C3−/− mice is not based on differences in the anti-chlamydial IgG response (which is slightly delayed) as demonstrated by serum transfer experiments. In addition, during the first week of infection, the absence of C3 was associated with partial protection characterized by reduced weight loss, better clinical score and lower bacterial burden, which might be explained by a different mechanism. Lack of complement functions downstream of C5 had little effect. This study demonstrates for the first time a strong and complex influence of complement effector functions, downstream of C3 and upstream of C5, on the outcome of an infection with intracellular bacteria, such as C. psittaci. PMID:23189195

  20. Intracellular trafficking of integrins in cancer cells.

    PubMed

    Onodera, Yasuhito; Nam, Jin-Min; Sabe, Hisataka

    2013-10-01

    Integrins are heterodimeric cell surface receptors, which principally mediate the interaction between cells and their extracellular microenvironments. Because of their pivotal roles in cancer proliferation, survival, invasion and metastasis, integrins have been recognized as promising targets for cancer treatment. As is the case with other receptors, the localization of integrins on the cell surface has provided opportunities to block their functions by various inhibitory monoclonal antibodies. A number of small molecule agents blocking integrin-ligand binding have also been established, and some such agents are currently on the market or in clinical trials for some diseases including cancer. This review exclusively focuses on another strategy for cancer therapy, which comes from the obligate localization of integrins on the cell surface; targeting the intracellular trafficking of integrins. A number of studies have shown the essential roles of integrin trafficking in hallmarks of cancer, such as activation of oncogenic signaling pathways as well as acquisition of invasiveness. Recent findings have shown that increased integrin recycling activity is associated with some types of gain-of-function mutations of p53, a common feature of diverse types of cancers, which also indicates that targeting integrin recycling could be widely applicable and effective against many cancers. We also discuss possible therapeutic contexts where integrin trafficking can be effectively targeted, and what molecular interfaces may hopefully be druggable. PMID:23711790

  1. Dominant Obligate Anaerobes Revealed in Lower Respiratory Tract Infection in Horses by 16S rRNA Gene Sequencing

    PubMed Central

    KINOSHITA, Yuta; NIWA, Hidekazu; KATAYAMA, Yoshinari; HARIU, Kazuhisa

    2013-01-01

    ABSTRACT Obligate anaerobes are important etiological agents in pneumonia or pleuropneumonia in horses, because they are isolated more commonly from ill horses that have died or been euthanized than from those that survive. We performed bacterial identification and antimicrobial susceptibility testing for obligate anaerobes to establish effective antimicrobial therapy. We used 16S rRNA gene sequencing to identify 58 obligate anaerobes and compared the results with those from a phenotypic identification kit. The identification results of 16S rRNA gene sequencing were more reliable than those of the commercial kit. We concluded that genera Bacteroides and Prevotellaespecially B. fragilis and P. heparinolyticaare dominant anaerobes in lower respiratory tract infection in horses; these organisms were susceptible to metronidazole, imipenem and clindamycin. PMID:24366152

  2. Dominant obligate anaerobes revealed in lower respiratory tract infection in horses by 16S rRNA gene sequencing.

    PubMed

    Kinoshita, Yuta; Niwa, Hidekazu; Katayama, Yoshinari; Hariu, Kazuhisa

    2014-04-01

    Obligate anaerobes are important etiological agents in pneumonia or pleuropneumonia in horses, because they are isolated more commonly from ill horses that have died or been euthanized than from those that survive. We performed bacterial identification and antimicrobial susceptibility testing for obligate anaerobes to establish effective antimicrobial therapy. We used 16S rRNA gene sequencing to identify 58 obligate anaerobes and compared the results with those from a phenotypic identification kit. The identification results of 16S rRNA gene sequencing were more reliable than those of the commercial kit. We concluded that genera Bacteroides and Prevotella-especially B. fragilis and P. heparinolytica-are dominant anaerobes in lower respiratory tract infection in horses; these organisms were susceptible to metronidazole, imipenem and clindamycin. PMID:24366152

  3. NK Cell-Mediated Regulation of Protective Memory Responses against Intracellular Ehrlichial Pathogens

    PubMed Central

    Habib, Samar; El Andaloussi, Abdeljabar; Hisham, Ahmed; Ismail, Nahed

    2016-01-01

    Ehrlichiae are gram-negative obligate intracellular bacteria that cause potentially fatal human monocytic ehrlichiosis. We previously showed that natural killer (NK) cells play a critical role in host defense against Ehrlichia during primary infection. However, the contribution of NK cells to the memory response against Ehrlichia remains elusive. Primary infection of C57BL/6 mice with Ehrlichia muris provides long-term protection against a second challenge with the highly virulent Ixodes ovatus Ehrlichia (IOE), which ordinarily causes fatal disease in naïve mice. Here, we show that the depletion of NK cells in E. muris-primed mice abrogates the protective memory response against IOE. Approximately, 80% of NK cell-depleted E. muris-primed mice succumbed to lethal IOE infection on days 8–10 after IOE infection, similar to naïve mice infected with the same dose of IOE. The lack of a recall response in NK cell-depleted mice correlated with an increased bacterial burden, extensive liver injury, decreased frequency of Ehrlichia-specific IFN-γ-producing memory CD4+ and CD8+ T-cells, and a low titer of Ehrlichia-specific antibodies. Intraperitoneal infection of mice with E. muris resulted in the production of IL-15, IL-12, and IFN-γ as well as an expansion of activated NKG2D+ NK cells. The adoptive transfer of purified E. muris-primed hepatic and splenic NK cells into Rag2-/-Il2rg-/- recipient mice provided protective immunity against challenge with E. muris. Together, these data suggest that E. muris-induced memory-like NK cells, which contribute to the protective, recall response against Ehrlichia. PMID:27092553

  4. Informed consent: Enforcing pharmaceutical companies' obligations abroad.

    PubMed

    Lee, Stacey B

    2010-01-01

    The past several years have seen an evolution in the obligations of pharmaceutical companies conducting clinical trials abroad. Key players, such as international human rights organizations, multinational pharmaceutical companies, the United States government and courts, and the media, have played a significant role in defining these obligations. This article examines how such obligations have developed through the lens of past, present, and future recommendations for informed consent protections. In doing so, this article suggests that, no matter how robust obligations appear, they will continue to fall short of providing meaningful protection until they are accompanied by a substantive enforcement mechanism that holds multinational pharmaceutical companies accountable for their conduct. Issues of national sovereignty, particularly in the United States, will continue to prevent meaningful enforcement by an international tribunal or through one universally adopted code of ethics. This article argues that, rather than continuing to pursue an untenable international approach, the Alien Torts Statute (ATS) offers a viable enforcement mechanism, at least for US-based pharmaceutical companies. Recent federal appellate court precedent interpreting the ATS provides the mechanism for granting victims redress and enforcing accountability of sponsors (usually pharmaceutical companies and research and academic institutions) for informed consent misconduct. Substantive human rights protections are vital in order to ensure that every person can realize the "right to health." This article concludes that by building on the federal appellate court's ATS analysis, which grants foreign trial participants the right to pursue claims of human rights violations in US courts, a mechanism can be created for enforcing not only substantive informed consent, but also human rights protections. PMID:20930251

  5. Intracellular Sterol Dynamics

    PubMed Central

    Mesmin, Bruno; Maxfield, Frederick R.

    2009-01-01

    We review the cellular mechanisms implicated in cholesterol trafficking and distribution. Recent studies have provided new information about the distribution of sterols within cells, including analysis of its transbilayer distribution. The cholesterol interaction with other lipids and its engagement in various trafficking processes will determine its proper level in a specific membrane; making the cholesterol distribution uneven among the various intracellular organelles. The cholesterol content is important since cholesterol plays an essential role in membranes by controlling their physicochemical properties as well as key cellular events such as signal transduction and protein trafficking. Cholesterol movement between cellular organelles is highly dynamic, and can be achieved by vesicular and non-vesicular processes. Various studies have analyzed the proteins that play a significant role in these processes, giving us new information about the relative importance of these two trafficking pathways in cholesterol transport. Although still poorly characterized in many trafficking routes, several potential sterol transport proteins have been described in detail; as a result, molecular mechanisms for sterol transport among membranes start to be appreciated. PMID:19286471

  6. Value, obligation and the asymmetry question.

    PubMed

    Tooley, Michael

    1998-04-01

    Is there a prima facie obligation to produce additional individuals whose lives would be worth living? In his paper 'Is it good to make happy people?', Stuart Rachels argues not only that there is, but, also, that precisely as much weight should be assigned to the quality of life that would be enjoyed by such potential persons, if they were to be actualized, as to the quality of life enjoyed by actually existing persons. In response, I shall argue, first, that Rachels' view is exposed to very serious objections, and secondly, that his arguments in support of his position involve a crucial assumption, which cannot be sustained, concerning the relation between, on the one hand, propositions about good-making and bad-making properties, and, on the other, propositions about right-making and wrong-making ones. I shall then argue that there is a very plausible position concerning the conditions under which an action can be morally wrong which entails the following asymmetry: there is a prima facie obligation not to bring into existence individuals whose lives are not worth living, but there is no corresponding obligation to create additional individuals whose lives would be worth living. PMID:11655328

  7. Quantitative Proteomics of Intracellular Campylobacter jejuni Reveals Metabolic Reprogramming

    PubMed Central

    Liu, Xiaoyun; Gao, Beile; Novik, Veronica; Galán, Jorge E.

    2012-01-01

    Campylobacter jejuni is the major cause of bacterial food-borne illness in the USA and Europe. An important virulence attribute of this bacterial pathogen is its ability to enter and survive within host cells. Here we show through a quantitative proteomic analysis that upon entry into host cells, C. jejuni undergoes a significant metabolic downshift. Furthermore, our results indicate that intracellular C. jejuni reprograms its respiration, favoring the respiration of fumarate. These results explain the poor ability of C. jejuni obtained from infected cells to grow under standard laboratory conditions and provide the bases for the development of novel anti microbial strategies that would target relevant metabolic pathways. PMID:22412372

  8. Bacterial Vaginosis

    MedlinePlus

    ... About NIAID News & Events Volunteer NIAID > Health & Research Topics > Bacterial Vaginosis Skip Website Tools Website Tools Print this page Order publications Volunteer for Clinical Studies Help people ...

  9. Bacterial Proteasomes

    PubMed Central

    Jastrab, Jordan B.; Darwin, K. Heran

    2015-01-01

    Interest in bacterial proteasomes was sparked by the discovery that proteasomal degradation is required for the pathogenesis of Mycobacterium tuberculosis, one of the world's deadliest pathogens. Although bacterial proteasomes are structurally similar to their eukaryotic and archaeal homologs, there are key differences in their mechanisms of assembly, activation, and substrate targeting for degradation. In this article, we compare and contrast bacterial proteasomes with their archaeal and eukaryotic counterparts, and we discuss recent advances in our understanding of how bacterial proteasomes function to influence microbial physiology. PMID:26488274

  10. A Genetically Encoded FRET Sensor for Intracellular Heme.

    PubMed

    Song, Yanqun; Yang, Maiyun; Wegner, Seraphine V; Zhao, Jingyi; Zhu, Rongfeng; Wu, Yun; He, Chuan; Chen, Peng R

    2015-07-17

    Heme plays pivotal roles in various cellular processes as well as in iron homeostasis in living systems. Here, we report a genetically encoded fluorescence resonance energy transfer (FRET) sensor for selective heme imaging by employing a pair of bacterial heme transfer chaperones as the sensory components. This heme-specific probe allows spatial-temporal visualization of intracellular heme distribution within living cells. PMID:25860383

  11. Glutathione activates virulence gene expression of an intracellular pathogen

    PubMed Central

    Reniere, Michelle L.; Whiteley, Aaron T.; Hamilton, Keri L.; John, Sonya M.; Lauer, Peter; Brennan, Richard G.; Portnoy, Daniel A.

    2015-01-01

    Intracellular pathogens are responsible for much of the world-wide morbidity and mortality due to infectious diseases. To colonize their hosts successfully, pathogens must sense their environment and regulate virulence gene expression appropriately. Accordingly, on entry into mammalian cells, the facultative intracellular bacterial pathogen Listeria monocytogenes remodels its transcriptional program by activating the master virulence regulator PrfA. Here we show that bacterial and host-derived glutathione are required to activate PrfA. In this study a genetic selection led to the identification of a bacterial mutant in glutathione synthase that exhibited reduced virulence gene expression and was attenuated 150-fold in mice. Genome sequencing of suppressor mutants that arose spontaneously in vivo revealed a single nucleotide change in prfA that locks the protein in the active conformation (PrfA*) and completely bypassed the requirement for glutathione during infection. Biochemical and genetic studies support a model in which glutathione-dependent PrfA activation is mediated by allosteric binding of glutathione to PrfA. Whereas glutathione and other low-molecular-weight thiols have important roles in redox homeostasis in all forms of life, here we demonstrate that glutathione represents a critical signalling molecule that activates the virulence of an intracellular pathogen. PMID:25567281

  12. Salmonella enterica Serovar Typhimurium Response Involved in Attenuation of Pathogen Intracellular Proliferation

    PubMed Central

    Cano, David A.; Martínez-Moya, Marina; Pucciarelli, M. Graciela; Groisman, Eduardo A.; Casadesús, Josep; García-Del Portillo, Francisco

    2001-01-01

    Salmonella enterica serovar Typhimurium proliferates within cultured epithelial and macrophage cells. Intracellular bacterial proliferation is, however, restricted within normal fibroblast cells. To characterize this phenomenon in detail, we investigated the possibility that the pathogen itself might contribute to attenuating the intracellular growth rate. S. enterica serovar Typhimurium mutants were selected in normal rat kidney fibroblasts displaying an increased intracellular proliferation rate. These mutants harbored loss-of-function mutations in the virulence-related regulatory genes phoQ, rpoS, slyA, and spvR. Lack of a functional PhoP-PhoQ system caused the most dramatic change in the intracellular growth rate. phoP- and phoQ-null mutants exhibited an intracellular growth rate 20- to 30-fold higher than that of the wild-type strain. This result showed that the PhoP-PhoQ system exerts a master regulatory function for preventing bacterial overgrowth within fibroblasts. In addition, an overgrowing clone was isolated harboring a mutation in a previously unknown serovar Typhimurium open reading frame, named igaA for intracellular growth attenuator. Mutations in other serovar Typhimurium virulence genes, such as ompR, dam, crp, cya, mviA, spiR (ssrA), spiA, and rpoE, did not result in pathogen intracellular overgrowth. Nonetheless, lack of either SpiA or the alternate sigma factor RpoE led to a substantial decrease in intracellular bacterial viability. These results prove for the first time that specific serovar Typhimurium virulence regulators are involved in a response designed to attenuate the intracellular growth rate within a nonphagocytic host cell. This growth-attenuating response is accompanied by functions that ensure the viability of intracellular bacteria. PMID:11553591

  13. Intracellular Adaptation of Brucella abortus

    PubMed Central

    Lamontagne, Julie; Forest, Anik; Marazzo, Elena; Denis, François; Butler, Heather; Michaud, Jean-François; Boucher, Lyne; Pedro, Ida; Villeneuve, Annie; Sitnikov, Dmitri; Trudel, Karine; Nassif, Najib; Boudjelti, Djamila; Tomaki, Fadi; Chaves-Olarte, Esteban; Guzmán-Verri, Caterina; Brunet, Sylvain; Côté-Martin, Alexandra; Hunter, Joanna; Moreno, Edgardo; Paramithiotis, Eustache

    2009-01-01

    Macrophages were infected with virulent B. abortus strain 2308 or attenuated strain 19. Intracellular bacteria were recovered at different times after infection and their proteomes compared. The virulent strain initially reduced most biosynthesis and altered its respiration, adaptations reversed later in infection. The attenuated strain was unable to match the magnitude of the virulent strain’s adjustments. The results provide insight into mechanisms utilized by Brucella to establish intracellular infections. PMID:19216536

  14. Evaluation of the bacterial microbiome of two flea species using different DNA-isolation techniques provides insights into flea host ecology.

    PubMed

    Lawrence, Andrea L; Hii, Sze-Fui; Chong, Rowena; Webb, Cameron E; Traub, Rebecca; Brown, Graeme; Šlapeta, Jan

    2015-12-01

    Fleas (Siphonaptera) are ubiquitous blood-sucking pests of animals worldwide and are vectors of zoonotic bacteria such as Rickettsia and Bartonella. We performed Ion Torrent PGM amplicon sequencing for the bacterial 16S rRNA gene to compare the microbiome of the ubiquitous cat flea (Ctenocephalides f. felis) and the host-specific echidna stickfast flea (Echidnophaga a. ambulans) and evaluated potential bias produced during common genomic DNA-isolation methods. We demonstrated significant differences in the bacterial community diversity between the two flea species but not between protocols combining surface sterilisation with whole flea homogenisation or exoskeleton retention. Both flea species were dominated by obligate intracellular endosymbiont Wolbachia, and the echidna stickfast fleas possessed the endosymbiont Cardinium. Cat fleas that were not surface sterilised showed presence of Candidatus 'Rickettsia senegalensis' DNA, the first report of its presence in Australia. In the case of Rickettsia, we show that sequencing depth of 50 000 was required for comparable sensitivity with Rickettsia qPCR. Low-abundance bacterial genera are suggested to reflect host ecology. The deep-sequencing approach demonstrates feasibility of pathogen detection with simultaneous quantitative analysis and evaluation of the inter-relationship of microbes within vectors. PMID:26542076

  15. High-Throughput Intracellular Antimicrobial Susceptibility Testing of Legionella pneumophila.

    PubMed

    Chiaraviglio, Lucius; Kirby, James E

    2015-12-01

    Legionella pneumophila is a Gram-negative opportunistic human pathogen that causes a severe pneumonia known as Legionnaires' disease. Notably, in the human host, the organism is believed to replicate solely within an intracellular compartment, predominantly within pulmonary macrophages. Consequently, successful therapy is predicated on antimicrobials penetrating into this intracellular growth niche. However, standard antimicrobial susceptibility testing methods test solely for extracellular growth inhibition. Here, we make use of a high-throughput assay to characterize intracellular growth inhibition activity of known antimicrobials. For select antimicrobials, high-resolution dose-response analysis was then performed to characterize and compare activity levels in both macrophage infection and axenic growth assays. Results support the superiority of several classes of nonpolar antimicrobials in abrogating intracellular growth. Importantly, our assay results show excellent correlations with prior clinical observations of antimicrobial efficacy. Furthermore, we also show the applicability of high-throughput automation to two- and three-dimensional synergy testing. High-resolution isocontour isobolograms provide in vitro support for specific combination antimicrobial therapy. Taken together, findings suggest that high-throughput screening technology may be successfully applied to identify and characterize antimicrobials that target bacterial pathogens that make use of an intracellular growth niche. PMID:26392509

  16. Bacterial Exotoxins and the Inflammasome

    PubMed Central

    Greaney, Allison J.; Leppla, Stephen H.; Moayeri, Mahtab

    2015-01-01

    The inflammasomes are intracellular protein complexes that play an important role in innate immune sensing. Activation of inflammasomes leads to activation of caspase-1 and maturation and secretion of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18. In certain myeloid cells, this activation can also lead to an inflammatory cell death (pyroptosis). Inflammasome sensor proteins have evolved to detect a range of microbial ligands and bacterial exotoxins either through direct interaction or by detection of host cell changes elicited by these effectors. Bacterial exotoxins activate the inflammasomes through diverse processes, including direct sensor cleavage, modulation of ion fluxes through plasma membrane pore formation, and perturbation of various host cell functions. In this review, we summarize the findings on some of the bacterial exotoxins that activate the inflammasomes. PMID:26617605

  17. "Obligated aliens": recognizing sperm donors' ethical obligation to disclose genetic information.

    PubMed

    Tamir, Sivan

    2013-03-01

    Sperm donors' obligations are typically constrained to the immediate circumstances surrounding the donation and to its time frame. This paper makes the case for recognizing an ongoing ethical obligation that binds sperm donors to disclose, in a timely manner, meaningful genetic information to recipients and donor-conceived children. The paper delineates and conceptualizes the suggested (potentially reciprocal) duty and argues that it is not the genetic link between the donor and the donor-conceived child that binds donors by said duty, but rather social responsibility. Accordingly, an original perception of the donor as an obligated alien is suggested and developed. The main thesis of the paper is supported inter alia by a comparison between transmitting infectious diseases and passing faulty genes on to donor-conceived children. The paper also provides an in-depth analysis of the conflicting interests of the parties generated by such an obligation and proposes a model for embedding this ethical duty in a (legal) contractual framework. PMID:23678628

  18. Is there a moral obligation not to infect others?

    PubMed

    Harris, J; Holm, S

    1995-11-01

    The emergence of HIV infection and AIDS has refocused concern on the obligations surrounding the carrying and transmission of communicable diseases. This article asks three related questions: Is there a general duty not to spread contagion? Are there special obligations not to communicate disease in the workplace? And does the mode of transmission of the disease affect the ethics of transmission and, if so, how and to what extent? There seems to be a strong prima facie obligation not to harm others by making them ill where this is avoidable, and this obligation not to communicate disease applies as much to relatively trivial diseases like the common cold as it does to HIV disease. The reasonableness of expecting people to live up to this obligation, however, depends on society reciprocating the obligation in the form of providing protection and compensation. PMID:7488907

  19. Bacterial Vaginosis

    MedlinePlus

    ... incubation period for bacterial vaginosis. How Is the Diagnosis Made? Your childs pediatrician can make the diagnosis ... Editorial Policy This site complies with the HONcode standard for trustworthy health information: verify here. Copyright 2016 ...

  20. Experimental replacement of an obligate insect symbiont

    PubMed Central

    Moran, Nancy A.; Yun, Yueli

    2015-01-01

    Symbiosis, the close association of unrelated organisms, has been pivotal in biological diversification. In the obligate symbioses found in many insect hosts, organisms that were once independent are permanently and intimately associated, resulting in expanded ecological capabilities. The primary model for this kind of symbiosis is the association between the bacterium Buchnera and the pea aphid (Acyrthosiphon pisum). A longstanding obstacle to efforts to illuminate genetic changes underlying obligate symbioses has been the inability to experimentally disrupt and reconstitute symbiont–host partnerships. Our experiments show that Buchnera can be experimentally transferred between aphid matrilines and, furthermore, that Buchnera replacement has a massive effect on host fitness. Using a recipient pea aphid matriline containing Buchnera that are heat sensitive because of an allele eliminating the heat shock response of a small chaperone, we reduced native Buchnera through heat exposure and introduced a genetically distinct Buchnera from another matriline, achieving complete replacement and stable inheritance. This transfer disrupted 100 million years (∼1 billion generations) of continuous maternal transmission of Buchnera in its host aphids. Furthermore, aphids with the Buchnera replacement enjoyed a dramatic increase in heat tolerance, directly demonstrating a strong effect of symbiont genotype on host ecology. PMID:25561531

  1. Experimental replacement of an obligate insect symbiont.

    PubMed

    Moran, Nancy A; Yun, Yueli

    2015-02-17

    Symbiosis, the close association of unrelated organisms, has been pivotal in biological diversification. In the obligate symbioses found in many insect hosts, organisms that were once independent are permanently and intimately associated, resulting in expanded ecological capabilities. The primary model for this kind of symbiosis is the association between the bacterium Buchnera and the pea aphid (Acyrthosiphon pisum). A longstanding obstacle to efforts to illuminate genetic changes underlying obligate symbioses has been the inability to experimentally disrupt and reconstitute symbiont-host partnerships. Our experiments show that Buchnera can be experimentally transferred between aphid matrilines and, furthermore, that Buchnera replacement has a massive effect on host fitness. Using a recipient pea aphid matriline containing Buchnera that are heat sensitive because of an allele eliminating the heat shock response of a small chaperone, we reduced native Buchnera through heat exposure and introduced a genetically distinct Buchnera from another matriline, achieving complete replacement and stable inheritance. This transfer disrupted 100 million years (∼ 1 billion generations) of continuous maternal transmission of Buchnera in its host aphids. Furthermore, aphids with the Buchnera replacement enjoyed a dramatic increase in heat tolerance, directly demonstrating a strong effect of symbiont genotype on host ecology. PMID:25561531

  2. Metabolic Complementarity and Genomics of the Dual Bacterial Symbiosis of Sharpshooters

    PubMed Central

    Wu, Dongying; Daugherty, Sean C; Van Aken, Susan E; Pai, Grace H; Watkins, Kisha L; Khouri, Hoda; Tallon, Luke J; Zaborsky, Jennifer M; Dunbar, Helen E; Tran, Phat L; Moran, Nancy A

    2006-01-01

    Mutualistic intracellular symbiosis between bacteria and insects is a widespread phenomenon that has contributed to the global success of insects. The symbionts, by provisioning nutrients lacking from diets, allow various insects to occupy or dominate ecological niches that might otherwise be unavailable. One such insect is the glassy-winged sharpshooter (Homalodisca coagulata), which feeds on xylem fluid, a diet exceptionally poor in organic nutrients. Phylogenetic studies based on rRNA have shown two types of bacterial symbionts to be coevolving with sharpshooters: the gamma-proteobacterium Baumannia cicadellinicola and the Bacteroidetes species Sulcia muelleri. We report here the sequencing and analysis of the 686,192–base pair genome of B. cicadellinicola and approximately 150 kilobase pairs of the small genome of S. muelleri, both isolated from H. coagulata. Our study, which to our knowledge is the first genomic analysis of an obligate symbiosis involving multiple partners, suggests striking complementarity in the biosynthetic capabilities of the two symbionts: B. cicadellinicola devotes a substantial portion of its genome to the biosynthesis of vitamins and cofactors required by animals and lacks most amino acid biosynthetic pathways, whereas S. muelleri apparently produces most or all of the essential amino acids needed by its host. This finding, along with other results of our genome analysis, suggests the existence of metabolic codependency among the two unrelated endosymbionts and their insect host. This dual symbiosis provides a model case for studying correlated genome evolution and genome reduction involving multiple organisms in an intimate, obligate mutualistic relationship. In addition, our analysis provides insight for the first time into the differences in symbionts between insects (e.g., aphids) that feed on phloem versus those like H. coagulata that feed on xylem. Finally, the genomes of these two symbionts provide potential targets for controlling plant pathogens such as Xylella fastidiosa, a major agroeconomic problem, for which H. coagulata and other sharpshooters serve as vectors of transmission. PMID:16729848

  3. Release of lipopolysaccharide from intracellular compartments containing Salmonella typhimurium to vesicles of the host epithelial cell.

    PubMed Central

    Garcia-del Portillo, F; Stein, M A; Finlay, B B

    1997-01-01

    The biological effects of bacterial lipopolysaccharide (LPS) on eucaryotic cells have traditionally been characterized following extracellular challenge of LPS on susceptible cells. In this study, we report the capacity of Salmonella typhimurium to release LPS once it is located in the intracellular environment of cultured epithelial cells. LPS is liberated from vacuolar compartments, where intracellular bacteria reside, to vesicles present in the host cell cytosol. The vesicle-associated LPS is detected in infected cells from the time when invading bacteria enter the host cell. Release of LPS is restricted to S. typhimurium-infected cells, with no LPS observed in neighboring uninfected cells, suggesting that dissemination of LPS occurs entirely within the intracellular environment of the infected cell. The amount of LPS present in host vesicles reaches a maximum when intracellular S. typhimurium cells start to proliferate, a time at which the entire host cell cytosol is filled with numerous vesicles containing LPS. All these data support the concept that intracellular bacterial pathogens might signal the host cell from intracellular locations by releasing bioactive bacterial components such as LPS. PMID:8975888

  4. Bacterial rheotaxis.

    PubMed

    Marcos; Fu, Henry C; Powers, Thomas R; Stocker, Roman

    2012-03-27

    The motility of organisms is often directed in response to environmental stimuli. Rheotaxis is the directed movement resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates, and spermatozoa. Using carefully controlled microfluidic flows, we show that rheotaxis also occurs in bacteria. Excellent quantitative agreement between experiments with Bacillus subtilis and a mathematical model reveals that bacterial rheotaxis is a purely physical phenomenon, in contrast to fish rheotaxis but in the same way as sperm rheotaxis. This previously unrecognized bacterial taxis results from a subtle interplay between velocity gradients and the helical shape of flagella, which together generate a torque that alters a bacterium's swimming direction. Because this torque is independent of the presence of a nearby surface, bacterial rheotaxis is not limited to the immediate neighborhood of liquid-solid interfaces, but also takes place in the bulk fluid. We predict that rheotaxis occurs in a wide range of bacterial habitats, from the natural environment to the human body, and can interfere with chemotaxis, suggesting that the fitness benefit conferred by bacterial motility may be sharply reduced in some hydrodynamic conditions. PMID:22411815

  5. Bacterial rheotaxis

    PubMed Central

    Marcos; Fu, Henry C.; Powers, Thomas R.; Stocker, Roman

    2012-01-01

    The motility of organisms is often directed in response to environmental stimuli. Rheotaxis is the directed movement resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates, and spermatozoa. Using carefully controlled microfluidic flows, we show that rheotaxis also occurs in bacteria. Excellent quantitative agreement between experiments with Bacillus subtilis and a mathematical model reveals that bacterial rheotaxis is a purely physical phenomenon, in contrast to fish rheotaxis but in the same way as sperm rheotaxis. This previously unrecognized bacterial taxis results from a subtle interplay between velocity gradients and the helical shape of flagella, which together generate a torque that alters a bacterium's swimming direction. Because this torque is independent of the presence of a nearby surface, bacterial rheotaxis is not limited to the immediate neighborhood of liquid–solid interfaces, but also takes place in the bulk fluid. We predict that rheotaxis occurs in a wide range of bacterial habitats, from the natural environment to the human body, and can interfere with chemotaxis, suggesting that the fitness benefit conferred by bacterial motility may be sharply reduced in some hydrodynamic conditions. PMID:22411815

  6. Metallochaperones Regulate Intracellular Copper Levels

    PubMed Central

    Pang, W. Lee; Kaur, Amardeep; Ratushny, Alexander V.; Cvetkovic, Aleksandar; Kumar, Sunil; Pan, Min; Arkin, Adam P.; Aitchison, John D.; Adams, Michael W. W.; Baliga, Nitin S.

    2013-01-01

    Copper (Cu) is an important enzyme co-factor that is also extremely toxic at high intracellular concentrations, making active efflux mechanisms essential for preventing Cu accumulation. Here, we have investigated the mechanistic role of metallochaperones in regulating Cu efflux. We have constructed a computational model of Cu trafficking and efflux based on systems analysis of the Cu stress response of Halobacterium salinarum. We have validated several model predictions via assays of transcriptional dynamics and intracellular Cu levels, discovering a completely novel function for metallochaperones. We demonstrate that in addition to trafficking Cu ions, metallochaperones also function as buffers to modulate the transcriptional responsiveness and efficacy of Cu efflux. This buffering function of metallochaperones ultimately sets the upper limit for intracellular Cu levels and provides a mechanistic explanation for previously observed Cu metallochaperone mutation phenotypes. PMID:23349626

  7. The Obligation to Participate in Biomedical Research

    PubMed Central

    Schaefer, G. Owen; Emanuel, Ezekiel J.; Wertheimer, Alan

    2009-01-01

    The prevailing view is that participation in biomedical research is above and beyond the call of duty. While some commentators have offered reasons against this, we propose a novel public goods argument for an obligation to participate in biomedical research. Biomedical knowledge is a public good, available to any individual even if that individual does not contribute to it. Participation in research is a critical way to support that important public good. Consequently, we all have a duty to participate. The current social norm is that people participate only if they have a good reason to do so. The public goods argument implies that people should participate unless they have a good reason not to. Such a shift would be of great aid to the progress of biomedical research, eventually making our society significantly healthier and longer-lived. PMID:19567441

  8. Ethical theory, "common morality," and professional obligations.

    PubMed

    Alexandra, Andrew; Miller, Seumas

    2009-01-01

    We have two aims in this paper. The first is negative: to demonstrate the problems in Bernard Gert's account of common morality, in particular as it applies to professional morality. The second is positive: to suggest a more satisfactory explanation of the moral basis of professional role morality, albeit one that is broadly consistent with Gert's notion of common morality, but corrects and supplements Gert's theory. The paper is in three sections. In the first, we sketch the main features of Gert's account of common morality in general. In the second, we outline Gert's explanation of the source of professional moral rules and demonstrate its inadequacy. In the third section, we provide an account of our own collectivist needs-based view of the source of the role-moral obligations of many professional roles, including those of health care professionals. PMID:19199076

  9. Intracellular recording in behaving animals

    PubMed Central

    Long, Michael A.; Lee, Albert K.

    2011-01-01

    Electrophysiological recordings from behaving animals provide an unparalleled view into the functional role of individual neurons. Intracellular approaches can be especially revealing as they provide information about a neuron’s inputs and intrinsic cellular properties, which together determine its spiking output. Recent technical developments have made intracellular recording possible during an ever-increasing range of behaviors in both head-fixed and freely moving animals. These recordings have yielded fundamental insights into the cellular and circuit mechanisms underlying neural activity during natural behaviors in such areas as sensory perception, motor sequence generation, and spatial navigation, forging a direct link between cellular and systems neuroscience. PMID:22054814

  10. 12 CFR 560.42 - State and local government obligations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 6 2012-01-01 2012-01-01 false State and local government obligations. 560.42 Section 560.42 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY LENDING AND INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.42 State and local government obligations. (a) What...

  11. 48 CFR 252.239-7013 - Obligation of the Government.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Government. 252.239-7013 Section 252.239-7013 Federal Acquisition Regulations System DEFENSE ACQUISITION... of Provisions And Clauses 252.239-7013 Obligation of the Government. As prescribed in 239.7411(c), use the following clause: Obligation of the Government (JUL 2006) (a) This basic agreement is not...

  12. 18 CFR 367.22 - Accounting for asset retirement obligations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Accounting for asset... GAS ACT General Instructions § 367.22 Accounting for asset retirement obligations. (a) An asset... obligation. For purposes of analysis, a service company must maintain supporting documentation so as to...

  13. 13 CFR 500.213 - Termination of obligations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Termination of obligations. 500.213 Section 500.213 Business Credit and Assistance EMERGENCY OIL AND GAS GUARANTEED LOAN BOARD EMERGENCY OIL AND GAS GUARANTEED LOAN PROGRAM Oil and Gas Guaranteed Loans § 500.213 Termination of obligations. (a) The Board, in its discretion, shall...

  14. 29 CFR 1985.102 - Obligations and prohibited acts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false Obligations and prohibited acts. 1985.102 Section 1985.102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Preliminary Orders § 1985.102 Obligations and prohibited acts. (a) No covered person or service provider...

  15. 22 CFR 221.15 - Fiscal Agent obligations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Fiscal Agent obligations. 221.15 Section 221.15 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS The Guarantee § 221.15 Fiscal Agent obligations. Failure of the Fiscal Agent to perform any of...

  16. 22 CFR 221.15 - Fiscal Agent obligations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Fiscal Agent obligations. 221.15 Section 221.15 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS The Guarantee § 221.15 Fiscal Agent obligations. Failure of the Fiscal Agent to perform any of...

  17. 22 CFR 221.15 - Fiscal Agent obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Fiscal Agent obligations. 221.15 Section 221.15 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS The Guarantee § 221.15 Fiscal Agent obligations. Failure of the Fiscal Agent to perform any of...

  18. 22 CFR 221.15 - Fiscal Agent obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Fiscal Agent obligations. 221.15 Section 221.15 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS The Guarantee § 221.15 Fiscal Agent obligations. Failure of the Fiscal Agent to perform any of...

  19. 22 CFR 221.15 - Fiscal Agent obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Fiscal Agent obligations. 221.15 Section 221.15 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS The Guarantee § 221.15 Fiscal Agent obligations. Failure of the Fiscal Agent to perform any of...

  20. 34 CFR 686.40 - Documenting the service obligation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (TEACH) GRANT PROGRAM Service and Repayment Obligations § 686.40 Documenting the service obligation. (a... in a program of study for which a TEACH Grant was received, the grant recipient must confirm to the... period being certified in any of the high-need fields of mathematics, science, a foreign...

  1. 12 CFR 160.42 - State and local government obligations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false State and local government obligations. 160.42 Section 160.42 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY LENDING AND INVESTMENT § 160.42 State and local government obligations. (a) Pursuant to HOLA section 5(c)(1)(H),...

  2. 12 CFR 160.42 - State and local government obligations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false State and local government obligations. 160.42 Section 160.42 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY LENDING AND INVESTMENT § 160.42 State and local government obligations. (a) What limitations apply? Pursuant to...

  3. 7 CFR 4274.355 - Loan approval and obligating funds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 4274.355 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS... Intermediary Relending Program (IRP) § 4274.355 Loan approval and obligating funds. The loan will be considered approved on the date the signed copy of the obligation of funds document is mailed to the intermediary....

  4. 7 CFR 4274.355 - Loan approval and obligating funds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 4274.355 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS... Intermediary Relending Program (IRP) § 4274.355 Loan approval and obligating funds. The loan will be considered approved on the date the signed copy of the obligation of funds document is mailed to the intermediary....

  5. 7 CFR 4274.355 - Loan approval and obligating funds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 4274.355 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS... Intermediary Relending Program (IRP) § 4274.355 Loan approval and obligating funds. The loan will be considered approved on the date the signed copy of the obligation of funds document is mailed to the intermediary....

  6. 7 CFR 4274.355 - Loan approval and obligating funds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 4274.355 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS... Intermediary Relending Program (IRP) § 4274.355 Loan approval and obligating funds. The loan will be considered approved on the date the signed copy of the obligation of funds document is mailed to the intermediary....

  7. 7 CFR 4274.355 - Loan approval and obligating funds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 4274.355 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS... Intermediary Relending Program (IRP) § 4274.355 Loan approval and obligating funds. The loan will be considered approved on the date the signed copy of the obligation of funds document is mailed to the intermediary....

  8. 29 CFR 4043.20 - Post-Event filing obligation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Post-Event filing obligation. 4043.20 Section 4043.20 Labor... EVENTS AND CERTAIN OTHER NOTIFICATION REQUIREMENTS Post-Event Notice of Reportable Events § 4043.20 Post-Event filing obligation. The plan administrator and each contributing sponsor of a plan for which...

  9. 11 CFR 9034.5 - Net outstanding campaign obligations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Net outstanding campaign obligations. 9034.5 Section 9034.5 Federal Elections FEDERAL ELECTION COMMISSION PRESIDENTIAL ELECTION CAMPAIGN FUND: PRESIDENTIAL PRIMARY MATCHING FUND ENTITLEMENTS § 9034.5 Net outstanding campaign obligations. (a) Within 15 calendar days after the candidate's date...

  10. 24 CFR 291.565 - Continuing obligations after purchase.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Continuing obligations after purchase. 291.565 Section 291.565 Housing and Urban Development Regulations Relating to Housing and Urban... Neighbor Next Door Sales Program § 291.565 Continuing obligations after purchase. To remain in...

  11. 24 CFR 291.565 - Continuing obligations after purchase.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Continuing obligations after purchase. 291.565 Section 291.565 Housing and Urban Development Regulations Relating to Housing and Urban... Neighbor Next Door Sales Program § 291.565 Continuing obligations after purchase. To remain in...

  12. 24 CFR 291.565 - Continuing obligations after purchase.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Continuing obligations after purchase. 291.565 Section 291.565 Housing and Urban Development Regulations Relating to Housing and Urban... Neighbor Next Door Sales Program § 291.565 Continuing obligations after purchase. To remain in...

  13. 24 CFR 291.565 - Continuing obligations after purchase.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Continuing obligations after purchase. 291.565 Section 291.565 Housing and Urban Development Regulations Relating to Housing and Urban... Neighbor Next Door Sales Program § 291.565 Continuing obligations after purchase. To remain in...

  14. 24 CFR 291.565 - Continuing obligations after purchase.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Continuing obligations after purchase. 291.565 Section 291.565 Housing and Urban Development Regulations Relating to Housing and Urban... Neighbor Next Door Sales Program § 291.565 Continuing obligations after purchase. To remain in...

  15. 10 CFR 600.29 - Fixed obligation awards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Fixed obligation awards. 600.29 Section 600.29 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS FINANCIAL ASSISTANCE RULES General § 600.29 Fixed obligation awards. (a) General. This section contains provisions applicable to the award of financial assistance instruments on a fixed amount...

  16. Deconfounding Distance Effects in Judgments of Moral Obligation

    ERIC Educational Resources Information Center

    Nagel, Jonas; Waldmann, Michael R.

    2013-01-01

    A heavily disputed question of moral philosophy is whether spatial distance between agent and victim is normatively relevant for the degree of obligation to help strangers in need. In this research, we focus on the associated descriptive question whether increased distance does in fact reduce individuals' sense of helping obligation. One problem…

  17. 29 CFR 4043.61 - Advance reporting filing obligation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Advance reporting filing obligation. 4043.61 Section 4043... TERMINATIONS REPORTABLE EVENTS AND CERTAIN OTHER NOTIFICATION REQUIREMENTS Advance Notice of Reportable Events § 4043.61 Advance reporting filing obligation. (a) In general. Unless a waiver or extension applies...

  18. 23 CFR 230.205 - Supportive services funds obligation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Supportive services funds obligation. 230.205 Section 230.205 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Supportive Services for Minority, Disadvantaged, and Women Business Enterprises § 230.205 Supportive services funds obligation....

  19. 47 CFR 25.701 - Public interest obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... COMMUNICATIONS Public Interest Obligations § 25.701 Public interest obligations. (a) DBS providers are subject to... used in this section, DBS providers are any of the following: (1) Entities licensed to operate satellites in the 12.2 to 12.7 GHz DBS frequency bands; or (2) Entities licensed to operate satellites in...

  20. 47 CFR 25.701 - Public interest obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... COMMUNICATIONS Public Interest Obligations § 25.701 Public interest obligations. (a) DBS providers are subject to... used in this section, DBS providers are any of the following: (1) Entities licensed to operate satellites in the 12.2 to 12.7 GHz DBS frequency bands; or (2) Entities licensed to operate satellites in...

  1. 47 CFR 25.701 - Public interest obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... COMMUNICATIONS Public Interest Obligations § 25.701 Public interest obligations. (a) DBS providers are subject to... used in this section, DBS providers are any of the following: (1) Entities licensed to operate satellites in the 12.2 to 12.7 GHz DBS frequency bands; or (2) Entities licensed to operate satellites in...

  2. 47 CFR 25.701 - Public interest obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... COMMUNICATIONS Public Interest Obligations § 25.701 Public interest obligations. (a) DBS providers are subject to... used in this section, DBS providers are any of the following: (1) Entities licensed to operate satellites in the 12.2 to 12.7 GHz DBS frequency bands; or (2) Entities licensed to operate satellites in...

  3. 47 CFR 25.701 - Public interest obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... COMMUNICATIONS Public Interest Obligations § 25.701 Public interest obligations. (a) DBS providers are subject to... used in this section, DBS providers are any of the following: (1) Entities licensed to operate satellites in the 12.2 to 12.7 GHz DBS frequency bands; or (2) Entities licensed to operate satellites in...

  4. 47 CFR 64.3001 - Obligation to transmit 911 calls.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Obligation to transmit 911 calls. 64.3001 Section 64.3001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Obligation to transmit 911 calls. All telecommunications carriers shall transmit all 911 calls to a PSAP,...

  5. 47 CFR 64.3001 - Obligation to transmit 911 calls.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Obligation to transmit 911 calls. 64.3001 Section 64.3001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Obligation to transmit 911 calls. All telecommunications carriers shall transmit all 911 calls to a PSAP,...

  6. 47 CFR 64.3001 - Obligation to transmit 911 calls.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Obligation to transmit 911 calls. 64.3001 Section 64.3001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Obligation to transmit 911 calls. All telecommunications carriers shall transmit all 911 calls to a PSAP,...

  7. 47 CFR 64.3001 - Obligation to transmit 911 calls.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Obligation to transmit 911 calls. 64.3001 Section 64.3001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Obligation to transmit 911 calls. All telecommunications carriers shall transmit all 911 calls to a PSAP,...

  8. 47 CFR 64.3001 - Obligation to transmit 911 calls.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Obligation to transmit 911 calls. 64.3001 Section 64.3001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Obligation to transmit 911 calls. All telecommunications carriers shall transmit all 911 calls to a PSAP,...

  9. 12 CFR 614.4358 - Computation of obligations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Computation of obligations. 614.4358 Section 614.4358 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM LOAN POLICIES AND OPERATIONS Lending and Leasing Limits § 614.4358 Computation of obligations. (a) Inclusions. The computation of...

  10. 12 CFR 1.100 - Indirect general obligations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Indirect general obligations. 1.100 Section 1.100 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY INVESTMENT SECURITIES.... These lease/rental agreement may, for instance, provide support for obligations financing...

  11. 12 CFR 1.100 - Indirect general obligations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Indirect general obligations. 1.100 Section 1.100 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY INVESTMENT SECURITIES.... These lease/rental agreement may, for instance, provide support for obligations financing...

  12. 22 CFR 62.9 - General obligations of sponsors.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false General obligations of sponsors. 62.9 Section 62.9 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM General Provisions § 62.9 General obligations of sponsors. (a) Adherence to Department of...

  13. 22 CFR 62.9 - General obligations of sponsors.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false General obligations of sponsors. 62.9 Section 62.9 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM General Provisions § 62.9 General obligations of sponsors. (a) Adherence to Department of...

  14. 22 CFR 62.9 - General obligations of sponsors.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false General obligations of sponsors. 62.9 Section 62.9 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM General Provisions § 62.9 General obligations of sponsors. (a) Adherence to Department of...

  15. 22 CFR 62.9 - General obligations of sponsors.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false General obligations of sponsors. 62.9 Section 62.9 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM General Provisions § 62.9 General obligations of sponsors. (a) Adherence to Department of...

  16. 22 CFR 62.9 - General obligations of sponsors.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false General obligations of sponsors. 62.9 Section 62.9 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM General Provisions § 62.9 General obligations of sponsors. (a) Adherence to Department of...

  17. 22 CFR 211.5 - Obligations of cooperating sponsor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Obligations of cooperating sponsor. 211.5 Section 211.5 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT TRANSFER OF FOOD COMMODITIES FOR FOOD USE IN DISASTER RELIEF, ECONOMIC DEVELOPMENT AND OTHER ASSISTANCE § 211.5 Obligations of cooperating sponsor. (a) Operational Plans....

  18. 43 CFR 3162.5-1 - Environmental obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... assessment, as appropriate. These environmental documents will be used in determining whether or not an... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Environmental obligations. 3162.5-1... for Operating Rights Owners and Operators § 3162.5-1 Environmental obligations. (a) The operator...

  19. Deconfounding Distance Effects in Judgments of Moral Obligation

    ERIC Educational Resources Information Center

    Nagel, Jonas; Waldmann, Michael R.

    2013-01-01

    A heavily disputed question of moral philosophy is whether spatial distance between agent and victim is normatively relevant for the degree of obligation to help strangers in need. In this research, we focus on the associated descriptive question whether increased distance does in fact reduce individuals' sense of helping obligation. One problem

  20. Standard of care, institutional obligations, and distributive justice.

    PubMed

    MacKay, Douglas

    2015-05-01

    The problem of standard of care in clinical research concerns the level of treatment that investigators must provide to subjects in clinical trials. Commentators often formulate answers to this problem by appealing to two distinct types of obligations: professional obligations and natural duties. In this article, I investigate whether investigators also possess institutional obligations that are directly relevant to the problem of standard of care, that is, those obligations a person has because she occupies a particular institutional role. I examine two types of institutional contexts: (1) public research agencies - agencies or departments of states that fund or conduct clinical research in the public interest; and (2) private-for-profit corporations. I argue that investigators who are employed or have their research sponsored by the former have a distinctive institutional obligation to conduct their research in a way that is consistent with the state's duty of distributive justice to provide its citizens with access to basic health care, and its duty to aid citizens of lower income countries. By contrast, I argue that investigators who are employed or have their research sponsored by private-for-profit corporations do not possess this obligation nor any other institutional obligation that is directly relevant to the ethics of RCTs. My account of the institutional obligations of investigators aims to contribute to the development of a reasonable, distributive justice-based account of standard of care. PMID:24117682

  1. Reflections on Obligation, Professionalism and the 21st Century.

    ERIC Educational Resources Information Center

    Van Patten, James J.

    A moral order exists that imposes on human beings an obligation toward other human beings, both present and future. This obligation includes making sure that the environment is maintained in a way that will provide for the basic human needs of future generations; accepting the responsibilities of professionalism, including the maintenance of…

  2. 47 CFR 211.7 - Obligation of carriers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Obligation of carriers. 211.7 Section 211.7 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EMERGENCY RESTORATION PRIORITY PROCEDURES FOR TELECOMMUNICATIONS SERVICES § 211.7 Obligation of carriers. (a) During the continuance of a war in which the...

  3. 47 CFR 211.7 - Obligation of carriers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Obligation of carriers. 211.7 Section 211.7 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EMERGENCY RESTORATION PRIORITY PROCEDURES FOR TELECOMMUNICATIONS SERVICES § 211.7 Obligation of carriers. (a) During...

  4. 47 CFR 211.7 - Obligation of carriers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Obligation of carriers. 211.7 Section 211.7 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EMERGENCY RESTORATION PRIORITY PROCEDURES FOR TELECOMMUNICATIONS SERVICES § 211.7 Obligation of carriers. (a) During...

  5. 47 CFR 211.7 - Obligation of carriers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Obligation of carriers. 211.7 Section 211.7 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EMERGENCY RESTORATION PRIORITY PROCEDURES FOR TELECOMMUNICATIONS SERVICES § 211.7 Obligation of carriers. (a) During...

  6. Cultural Generality of the Integration of Obligation and Other Motives

    ERIC Educational Resources Information Center

    Yang, Jen-Shou

    2012-01-01

    The purpose of the present study is twofold. One is to assess the cultural generality of the information integration rule for moral obligation. The other is to examine how people integrate moral obligation and self-interest. Two studies were implemented following the functional measurement methodology with Chinese samples. Study 1 replicated the…

  7. 18 CFR 37.8 - Obligations of OASIS users.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Obligations of OASIS... Obligations of OASIS users. Each OASIS user must notify the Responsible Party one month in advance of initiating a significant amount of automated queries. The OASIS user must also notify the Responsible...

  8. 18 CFR 37.8 - Obligations of OASIS users.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Obligations of OASIS... Obligations of OASIS users. Each OASIS user must notify the Responsible Party one month in advance of initiating a significant amount of automated queries. The OASIS user must also notify the Responsible...

  9. 18 CFR 37.8 - Obligations of OASIS users.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Obligations of OASIS... Obligations of OASIS users. Each OASIS user must notify the Responsible Party one month in advance of initiating a significant amount of automated queries. The OASIS user must also notify the Responsible...

  10. 5 CFR 334.105 - Obligated service requirement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Obligated service requirement. 334.105 Section 334.105 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS TEMPORARY ASSIGNMENTS UNDER THE INTERGOVERNMENTAL PERSONNEL ACT (IPA) § 334.105 Obligated...

  11. 5 CFR 334.105 - Obligated service requirement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Obligated service requirement. 334.105 Section 334.105 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS TEMPORARY ASSIGNMENTS UNDER THE INTERGOVERNMENTAL PERSONNEL ACT (IPA) § 334.105 Obligated...

  12. 5 CFR 334.105 - Obligated service requirement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Obligated service requirement. 334.105 Section 334.105 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS TEMPORARY ASSIGNMENTS UNDER THE INTERGOVERNMENTAL PERSONNEL ACT (IPA) § 334.105 Obligated...

  13. 5 CFR 334.105 - Obligated service requirement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Obligated service requirement. 334.105 Section 334.105 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS TEMPORARY ASSIGNMENTS UNDER THE INTERGOVERNMENTAL PERSONNEL ACT (IPA) § 334.105 Obligated...

  14. 5 CFR 334.105 - Obligated service requirement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Obligated service requirement. 334.105 Section 334.105 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS TEMPORARY ASSIGNMENTS UNDER THE INTERGOVERNMENTAL PERSONNEL ACT (IPA) § 334.105 Obligated...

  15. 10 CFR 611.112 - Termination of obligations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Termination of obligations. 611.112 Section 611.112 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS ADVANCED TECHNOLOGY VEHICLES MANUFACTURER ASSISTANCE PROGRAM Direct Loan Program § 611.112 Termination of obligations. DOE, the Federal Financing Bank, and...

  16. 10 CFR 611.112 - Termination of obligations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Termination of obligations. 611.112 Section 611.112 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS ADVANCED TECHNOLOGY VEHICLES MANUFACTURER ASSISTANCE PROGRAM Direct Loan Program § 611.112 Termination of obligations. DOE, the Federal Financing Bank, and...

  17. 10 CFR 611.112 - Termination of obligations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Termination of obligations. 611.112 Section 611.112 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS ADVANCED TECHNOLOGY VEHICLES MANUFACTURER ASSISTANCE PROGRAM Direct Loan Program § 611.112 Termination of obligations. DOE, the Federal Financing Bank, and...

  18. 10 CFR 611.112 - Termination of obligations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Termination of obligations. 611.112 Section 611.112 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS ADVANCED TECHNOLOGY VEHICLES MANUFACTURER ASSISTANCE PROGRAM Direct Loan Program § 611.112 Termination of obligations. DOE, the Federal Financing Bank, and...

  19. 10 CFR 611.112 - Termination of obligations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Termination of obligations. 611.112 Section 611.112 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS ADVANCED TECHNOLOGY VEHICLES MANUFACTURER ASSISTANCE PROGRAM Direct Loan Program § 611.112 Termination of obligations. DOE, the Federal Financing Bank, and...

  20. 48 CFR 32.705 - Unenforceability of unauthorized obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Unenforceability of unauthorized obligations. 32.705 Section 32.705 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Contract Funding 32.705 Unenforceability of unauthorized obligations. Many supplies...

  1. 47 CFR 211.7 - Obligation of carriers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Obligation of carriers. 211.7 Section 211.7 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EMERGENCY RESTORATION PRIORITY PROCEDURES FOR TELECOMMUNICATIONS SERVICES § 211.7 Obligation of carriers. (a) During...

  2. 18 CFR 35.18 - Asset retirement obligations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Asset retirement obligations. 35.18 Section 35.18 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Other Filing Requirements § 35.18 Asset retirement obligations. (a) A public utility that files a...

  3. 18 CFR 35.18 - Asset retirement obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Asset retirement obligations. 35.18 Section 35.18 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Other Filing Requirements § 35.18 Asset retirement obligations. (a) A public utility that files a...

  4. 18 CFR 35.18 - Asset retirement obligations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Asset retirement obligations. 35.18 Section 35.18 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Other Filing Requirements § 35.18 Asset retirement obligations. (a) A public utility that files a...

  5. 18 CFR 35.18 - Asset retirement obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Asset retirement obligations. 35.18 Section 35.18 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Other Filing Requirements § 35.18 Asset retirement obligations. (a) A public utility that files a...

  6. 12 CFR 380.10 - Maximum obligation limitation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Maximum obligation limitation. 380.10 Section 380.10 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY ORDERLY LIQUIDATION AUTHORITY General and Miscellaneous Provisions § 380.10 Maximum obligation limitation. (a) General rule. The FDIC shall...

  7. 6 CFR 25.5 - Obligations of seller.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 6 Domestic Security 1 2011-01-01 2011-01-01 false Obligations of seller. 25.5 Section 25.5 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY REGULATIONS TO SUPPORT ANTI-TERRORISM BY FOSTERING EFFECTIVE TECHNOLOGIES § 25.5 Obligations of seller. (a) Liability Insurance Required. The Seller shall obtain liability...

  8. 7 CFR 984.54 - Establishment of obligation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Reserve Walnuts § 984.54 Establishment of obligation. (a) Reserve obligation. Whenever... kernelweight of certified merchantable walnuts equal to a quantity derived by the application of the...

  9. 7 CFR 984.54 - Establishment of obligation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Reserve Walnuts § 984.54 Establishment of obligation. (a) Reserve obligation. Whenever... kernelweight of certified merchantable walnuts equal to a quantity derived by the application of the...

  10. 7 CFR 984.54 - Establishment of obligation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Reserve Walnuts § 984.54 Establishment of obligation. (a) Reserve obligation. Whenever... kernelweight of certified merchantable walnuts equal to a quantity derived by the application of the...

  11. 7 CFR 984.54 - Establishment of obligation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Reserve Walnuts § 984.54 Establishment of obligation. (a) Reserve obligation. Whenever... kernelweight of certified merchantable walnuts equal to a quantity derived by the application of the...

  12. 7 CFR 984.54 - Establishment of obligation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Reserve Walnuts § 984.54 Establishment of obligation. (a) Reserve obligation. Whenever... kernelweight of certified merchantable walnuts equal to a quantity derived by the application of the...

  13. 7 CFR 783.7 - Obligations of a participant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Obligations of a participant. 783.7 Section 783.7 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS TREE ASSISTANCE PROGRAM § 783.7 Obligations of a participant. (a)...

  14. Is there a moral obligation to select healthy children?

    PubMed

    Jacobs, Benjamin Meir

    2015-08-01

    Reproductive decision-making in the post-genetic age is a minefield of complex ethical problems. One such problem centres on whether there is an obligation on reproducers to choose the best possible child. This paper focusses on a simplified scenario: there are two embryos to choose from, one of which will develop a condition that diminishes quality of life but would still have 'a life worth living', the other of which is normal. Is there an obligation to choose the healthier child? If so, what is the nature and scope of this obligation? The answer to these questions relies on a satisfactory answer to the non-identity problem (NIP). This paper explores several solutions to the NIP and argues for a solution grounded in the concept of harm. Various accounts of harm are discussed and synthesised to provide a new 'comparative bad state view' of harm. This account is used to justify the obligation to choose the healthier child. How far should this obligation go? This paper rejects the conservative position of 'procreative autonomy' - which holds that such obligations have no place in reproductive decisions - and the radical position of 'procreative beneficence' - which holds that there is an even stronger obligation to make the best possible child. The obligation to choose the healthier child may be over-ridden by countervailing reasons; the moral calculus in any individual case will be largely dependent on the expected quality of life of the child. PMID:25370604

  15. 18 CFR 367.22 - Accounting for asset retirement obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Accounting for asset... GAS ACT General Instructions § 367.22 Accounting for asset retirement obligations. (a) An asset... measurement changes to the initial liability for the legal obligation recorded in account 230,...

  16. 18 CFR 367.22 - Accounting for asset retirement obligations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Accounting for asset... GAS ACT General Instructions § 367.22 Accounting for asset retirement obligations. (a) An asset... measurement changes to the initial liability for the legal obligation recorded in account 230,...

  17. 18 CFR 367.22 - Accounting for asset retirement obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Accounting for asset... GAS ACT General Instructions § 367.22 Accounting for asset retirement obligations. (a) An asset... measurement changes to the initial liability for the legal obligation recorded in account 230,...

  18. 37 CFR 251.30 - Basic obligations of arbitrators.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... principles where applicable. (1) Arbitrators are engaged in a matter of trust that requires them to place... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Basic obligations of... PROCEDURE Standards of Conduct § 251.30 Basic obligations of arbitrators. (a) Definitions. For purposes...

  19. Measurement of Religiosity and Work Obligations among Israeli Youth.

    ERIC Educational Resources Information Center

    Sagie, Abraham

    1993-01-01

    Reports on a study of 102 Israeli males, ages 22-30, on the relationship between religiosity and the obligation work norm. Finds that the level of obligation to work was significantly higher in the religious group than in the nonreligious group. (CFR)

  20. 7 CFR 623.11 - Obligations of the landowner.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Obligations of the landowner. 623.11 Section 623.11 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.11 Obligations of...

  1. Child Support Obligations and Low-Income Fathers

    ERIC Educational Resources Information Center

    Huang, Chien-Chung; Mincy, Ronald B.; Garfinkel, Irwin

    2005-01-01

    Using the 1994-1998 waves of the Current Population Survey--Child Support Supplement (N = 5,387), the aims of this study are to document child support obligation rates of nonresident fathers, to examine the effect of the obligation rate on child support compliance, and to calculate the trade-off between fathers' financial responsibility and…

  2. 7 CFR 1726.301 - Borrower contractual obligations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Borrower contractual obligations. 1726.301 Section 1726.301 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES RUS Standard Forms § 1726.301 Borrower contractual obligations....

  3. Identification of in vivo-induced bacterial protein antigens during calf infection with Chlamydia psittaci.

    PubMed

    Kästner, Julia; Saluz, Hans Peter; Hänel, Frank

    2015-05-01

    Chlamydia (C.) psittaci, the causative agent of ornithosis, is an obligate intracellular pathogen with a unique developmental cycle and a high potential for zoonotic transmission. Various mammalian hosts, such as cattle, horse, sheep and man that are in close contact with contaminated birds can get infected (referred to as psittacosis). Since little is known about long-term sequelae of chronic disease and the molecular mechanisms of chlamydial pathogenesis, a key step in understanding the in vivo situation is the identification of C. psittaci infection-associated proteins. For this, we investigated sera of infected calves. Using the immunoscreening approach In Vivo Induced Antigen Technology (IVIAT) including all relevant controls, we focused on C. psittaci proteins, which are induced in vivo during infection. Sera were pooled, extensively adsorbed against in vitro antigens to eliminate false positive results, and used to screen an inducible C. psittaci 02DC15 genomic expression library. Screening and control experiments revealed 19 immunogenic proteins, which are expressed during infection. They are involved in transport and oxidative stress response, heme and folate biosynthesis, DNA replication, recombination and repair, cell envelope, bacterial secretion systems and hypothetical proteins of so far unknown functions. Some of the proteins found may be considered as diagnostic markers or as candidates for the development of vaccines. PMID:25595025

  4. Dynamic Reorganization of Metabolic Enzymes into Intracellular Bodies

    PubMed Central

    OConnell, Jeremy D.; Zhao, Alice; Ellington, Andrew D.; Marcotte, Edward M.

    2013-01-01

    Both focused and large-scale cell biological and biochemical studies have revealed that hundreds of metabolic enzymes across diverse organisms form large intracellular bodies. These proteinaceous bodies range in form from fibers and intracellular focisuch as those formed by enzymes of nitrogen and carbon utilization and of nucleotide biosynthesisto high-density packings inside bacterial microcompartments and eukaryotic microbodies. Although many enzymes clearly form functional mega-assemblies, it is not yet clear for many recently discovered cases whether they represent functional entities, storage bodies, or aggregates. In this article, we survey intracellular protein bodies formed by metabolic enzymes, asking when and why such bodies form and what their formation implies for the functionalityand dysfunctionalityof the enzymes that comprise them. The panoply of intracellular protein bodies also raises interesting questions regarding their evolution and maintenance within cells. We speculate on models for how such structures form in the first place and why they may be inevitable. PMID:23057741

  5. Nutrient salvaging and metabolism by the intracellular pathogen Legionella pneumophila

    PubMed Central

    Fonseca, Maris V.; Swanson, Michele S.

    2014-01-01

    The Gram-negative bacterium Legionella pneumophila is ubiquitous in freshwater environments as a free-swimming organism, resident of biofilms, or parasite of protozoa. If the bacterium is aerosolized and inhaled by a susceptible human host, it can infect alveolar macrophages and cause a severe pneumonia known as Legionnaires' disease. A sophisticated cell differentiation program equips L. pneumophila to persist in both extracellular and intracellular niches. During its life cycle, L. pneumophila alternates between at least two distinct forms: a transmissive form equipped to infect host cells and evade lysosomal degradation, and a replicative form that multiplies within a phagosomal compartment that it has retooled to its advantage. The efficient changeover between transmissive and replicative states is fundamental to L. pneumophila's fitness as an intracellular pathogen. The transmission and replication programs of L. pneumophila are governed by a number of metabolic cues that signal whether conditions are favorable for replication or instead trigger escape from a spent host. Several lines of experimental evidence gathered over the past decade establish strong links between metabolism, cellular differentiation, and virulence of L. pneumophila. Herein, we focus on current knowledge of the metabolic components employed by intracellular L. pneumophila for cell differentiation, nutrient salvaging and utilization of host factors. Specifically, we highlight the metabolic cues that are coupled to bacterial differentiation, nutrient acquisition systems, and the strategies utilized by L. pneumophila to exploit host metabolites for intracellular replication. PMID:24575391

  6. Bacterial Vaginosis

    MedlinePlus

    ... of getting an STD. BV may also affect women who have never had sex. You cannot get BV from toilet seats, bedding, or swimming pools. How can I avoid getting bacterial vaginosis? Doctors and scientists do not completely understand how BV is spread, ...

  7. Bacterial Immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of bacterial agents reside in and around the environment that can cause illness and death in a poultry flock. Many cause disseminated disease while others exert more local effects such as the respiratory or gastrointestinal tract. The host, for our current purposes the laying hen, has de...

  8. Review of International Experience with Renewable Energy Obligation Support Mechanisms

    SciTech Connect

    Wiser, R.

    2005-06-01

    The main policy instruments currently used in the EU Member States to achieve the targets set for electricity produced from renewable energy sources are: (1) the quota obligation system; (2) the feed-in tariff system; and (3) the tendering system. The current study aims to review the experience gained with the quota obligation system. The report provides an overview of the regions where obligation systems have been implemented and contains a detailed evaluation of the performance of the obligation systems in the USA, the UK and in Sweden. The obligation systems in these countries have been evaluated based on the following criteria: Effectiveness; Market efficiency; Certainty for the renewable energy industry; Cost effectiveness; Stakeholder support for the obligation system; and Equity. The evaluation of international experiences with the obligation system gives rise to a mixed picture. Although an obligation in theory is effective and cost effective, it seems too early to conclude that the system delivers these promises in practice. On the one hand this is due to the limited period of implementation that makes it hard to distinguish between the direct effect of the system and some teething problems that will be solved in due time. On the other hand, the conclusion can be drawn that the obligation is a complex system, which will only function well if designed carefully. It does seem worthwhile, however, to continue monitoring the experiences with the obligation system abroad, because this will further reveal whether the system is indeed effective and cost effective in practice. In the longer term, e.g. beyond 2010, the introduction of an obligation system in the Netherlands could be considered. Finally, as the design of support schemes is being improved, it appears that the basic concepts of both the obligation system and the feed in system have been refined in such a way that the two systems are gradually converging. An important difference between the two systems however remains, namely that an obligation system relies more on market forces whereas the feed-in system is based on a greater involvement of the government.

  9. A lack of parasitic reduction in the obligate parasitic green alga Helicosporidium.

    PubMed

    Pombert, Jean-François; Blouin, Nicolas Achille; Lane, Chris; Boucias, Drion; Keeling, Patrick J

    2014-05-01

    The evolution of an obligate parasitic lifestyle is often associated with genomic reduction, in particular with the loss of functions associated with increasing host-dependence. This is evident in many parasites, but perhaps the most extreme transitions are from free-living autotrophic algae to obligate parasites. The best-known examples of this are the apicomplexans such as Plasmodium, which evolved from algae with red secondary plastids. However, an analogous transition also took place independently in the Helicosporidia, where an obligate parasite of animals with an intracellular infection mechanism evolved from algae with green primary plastids. We characterised the nuclear genome of Helicosporidium to compare its transition to parasitism with that of apicomplexans. The Helicosporidium genome is small and compact, even by comparison with the relatively small genomes of the closely related green algae Chlorella and Coccomyxa, but at the functional level we find almost no evidence for reduction. Nearly all ancestral metabolic functions are retained, with the single major exception of photosynthesis, and even here reduction is not complete. The great majority of genes for light-harvesting complexes, photosystems, and pigment biosynthesis have been lost, but those for other photosynthesis-related functions, such as Calvin cycle, are retained. Rather than loss of whole function categories, the predominant reductive force in the Helicosporidium genome is a contraction of gene family complexity, but even here most losses affect families associated with genome maintenance and expression, not functions associated with host-dependence. Other gene families appear to have expanded in response to parasitism, in particular chitinases, including those predicted to digest the chitinous barriers of the insect host or remodel the cell wall of Helicosporidium. Overall, the Helicosporidium genome presents a fascinating picture of the early stages of a transition from free-living autotroph to parasitic heterotroph where host-independence has been unexpectedly preserved. PMID:24809511

  10. A Lack of Parasitic Reduction in the Obligate Parasitic Green Alga Helicosporidium

    PubMed Central

    Pombert, Jean-François; Blouin, Nicolas Achille; Lane, Chris; Boucias, Drion; Keeling, Patrick J.

    2014-01-01

    The evolution of an obligate parasitic lifestyle is often associated with genomic reduction, in particular with the loss of functions associated with increasing host-dependence. This is evident in many parasites, but perhaps the most extreme transitions are from free-living autotrophic algae to obligate parasites. The best-known examples of this are the apicomplexans such as Plasmodium, which evolved from algae with red secondary plastids. However, an analogous transition also took place independently in the Helicosporidia, where an obligate parasite of animals with an intracellular infection mechanism evolved from algae with green primary plastids. We characterised the nuclear genome of Helicosporidium to compare its transition to parasitism with that of apicomplexans. The Helicosporidium genome is small and compact, even by comparison with the relatively small genomes of the closely related green algae Chlorella and Coccomyxa, but at the functional level we find almost no evidence for reduction. Nearly all ancestral metabolic functions are retained, with the single major exception of photosynthesis, and even here reduction is not complete. The great majority of genes for light-harvesting complexes, photosystems, and pigment biosynthesis have been lost, but those for other photosynthesis-related functions, such as Calvin cycle, are retained. Rather than loss of whole function categories, the predominant reductive force in the Helicosporidium genome is a contraction of gene family complexity, but even here most losses affect families associated with genome maintenance and expression, not functions associated with host-dependence. Other gene families appear to have expanded in response to parasitism, in particular chitinases, including those predicted to digest the chitinous barriers of the insect host or remodel the cell wall of Helicosporidium. Overall, the Helicosporidium genome presents a fascinating picture of the early stages of a transition from free-living autotroph to parasitic heterotroph where host-independence has been unexpectedly preserved. PMID:24809511

  11. The Evolution of Genomic Instability in the Obligate Endosymbionts of Whiteflies

    PubMed Central

    Sloan, Daniel B.; Moran, Nancy A.

    2013-01-01

    Many insects depend on ancient associations with intracellular bacteria to perform essential metabolic functions. These endosymbionts exhibit striking examples of convergence in genome architecture, including a high degree of structural stability that is not typical of their free-living counterparts. However, the recently sequenced genome of the obligate whitefly endosymbiont Portiera revealed features that distinguish it from other ancient insect associates, such as a low gene density and the presence of perfectly duplicated sequences. Here, we report the comparative analysis of Portiera genome sequences both within and between host species. In one whitefly lineage (Bemisia tabaci), we identify large-scale structural polymorphisms in the Portiera genome that exist even within individual insects. This variation is likely mediated by recombination across identical repeats that are maintained by gene conversion. The complete Portiera genome sequence from a distantly related whitefly host (Trialeurodes vaporarium) confirms a history of extensive genome rearrangement in this ancient endosymbiont. Using gene-order-based phylogenetic analysis, we show that the majority of rearrangements have occurred in the B. tabaci lineage, coinciding with an increase in the rate of nucleotide substitutions, a proliferation of short tandem repeats (microsatellites) in intergenic regions, and the loss of many widely conserved genes involved in DNA replication, recombination, and repair. These results indicate that the loss of recombinational machinery is unlikely to be the cause of the extreme structural conservation that is generally observed in obligate endosymbiont genomes and that large, repetitive intergenic regions are an important substrate for genomic rearrangements. PMID:23542079

  12. The evolution of genomic instability in the obligate endosymbionts of whiteflies.

    PubMed

    Sloan, Daniel B; Moran, Nancy A

    2013-01-01

    Many insects depend on ancient associations with intracellular bacteria to perform essential metabolic functions. These endosymbionts exhibit striking examples of convergence in genome architecture, including a high degree of structural stability that is not typical of their free-living counterparts. However, the recently sequenced genome of the obligate whitefly endosymbiont Portiera revealed features that distinguish it from other ancient insect associates, such as a low gene density and the presence of perfectly duplicated sequences. Here, we report the comparative analysis of Portiera genome sequences both within and between host species. In one whitefly lineage (Bemisia tabaci), we identify large-scale structural polymorphisms in the Portiera genome that exist even within individual insects. This variation is likely mediated by recombination across identical repeats that are maintained by gene conversion. The complete Portiera genome sequence from a distantly related whitefly host (Trialeurodes vaporarium) confirms a history of extensive genome rearrangement in this ancient endosymbiont. Using gene-order-based phylogenetic analysis, we show that the majority of rearrangements have occurred in the B. tabaci lineage, coinciding with an increase in the rate of nucleotide substitutions, a proliferation of short tandem repeats (microsatellites) in intergenic regions, and the loss of many widely conserved genes involved in DNA replication, recombination, and repair. These results indicate that the loss of recombinational machinery is unlikely to be the cause of the extreme structural conservation that is generally observed in obligate endosymbiont genomes and that large, repetitive intergenic regions are an important substrate for genomic rearrangements. PMID:23542079

  13. Magnetic microbes: Bacterial magnetite biomineralization

    SciTech Connect

    Prozorov, Tanya

    2015-09-14

    Magnetotactic bacteria are a diverse group of prokaryotes with the ability to orient and migrate along the magnetic field lines in search for a preferred oxygen concentration in chemically stratified water columns and sediments. These microorganisms produce magnetosomes, the intracellular nanometer-sized magnetic crystals surrounded by a phospholipid bilayer membrane, typically organized in chains. Magnetosomes have nearly perfect crystal structures with narrow size distribution and species-specific morphologies, leading to well-defined magnetic properties. As a result, the magnetite biomineralization in these organisms is of fundamental interest to diverse disciplines, from biotechnology to astrobiology. As a result, this article highlights recent advances in the understanding of the bacterial magnetite biomineralization.

  14. Professionalism for medicine: opportunities and obligations.

    PubMed

    Cruess, Sylvia R; Johnston, Sharon; Cruess, Richard L

    2004-01-01

    Physicians' dual roles--as healer and professional--are linked by codes of ethics governing behaviour and are empowered by science. Being part of a profession entails a societal contract. The profession is granted a monopoly over the use of a body of knowledge and the privilege of self-regulation and, in return, guarantees society professional competence, integrity and the provision of altruistic service. Societal attitudes to professionalism have changed from supportive to increasingly critical--with physicians being criticised for pursuing their own financial interests, and failing to self-regulate in a way that guarantees competence. Professional values are also threatened by many other factors. The most important are the changes in healthcare delivery in the developed world, with control shifting from the profession to the State and/or the corporate sector. For the ideal of professionalism to survive, physicians must understand it and its role in the social contract. They must meet the obligations necessary to sustain professionalism and ensure that healthcare systems support, rather than subvert, behaviour that is compatible with professionalism's values. PMID:15296199

  15. Conflicts in nurse educators' role obligations.

    PubMed

    Kopala, B

    1994-01-01

    Nurse educators face conflicting obligations to nursing students, patients, and agencies/institutions that require weighing and prioritizing values and choosing a course of action. Several hypotheses are explored about judgements commonly made in the pediatric clinical setting. These judgements are whether to permit a student to perform a procedure for the first time, make a potentially dangerous mistake, or provide patient care despite limited knowledge and skills. The hypotheses address the ranking of values of safety and student learning, the differences in value hierarchies of nurse educators and practicing nurses, and the use of patients as a means to an end--the education of nursing students. Although patients can be viewed as experiencing some actual or potential loss because students are learning while providing care, a concern is whether the patient "suffers greatly" or is "deprived of essentials." Case analyses suggest that for nurse educators: client safety appears to be the primary value, student learning takes precedence over the fullest achievement of most nursing practice values, the values hierarchy differs somewhat from that of the practicing nurse, and important nursing practice values may appear to be compromised to secure appropriate learning experiences for the student. PMID:7930170

  16. Intercellular nanotubes mediate bacterial communication.

    PubMed

    Dubey, Gyanendra P; Ben-Yehuda, Sigal

    2011-02-18

    Bacteria are known to communicate primarily via secreted extracellular factors. Here we identify a previously uncharacterized type of bacterial communication mediated by nanotubes that bridge neighboring cells. Using Bacillus subtilis as a model organism, we visualized transfer of cytoplasmic fluorescent molecules between adjacent cells. Additionally, by coculturing strains harboring different antibiotic resistance genes, we demonstrated that molecular exchange enables cells to transiently acquire nonhereditary resistance. Furthermore, nonconjugative plasmids could be transferred from one cell to another, thereby conferring hereditary features to recipient cells. Electron microscopy revealed the existence of variously sized tubular extensions bridging neighboring cells, serving as a route for exchange of intracellular molecules. These nanotubes also formed in an interspecies manner, between B. subtilis and Staphylococcus aureus, and even between B. subtilis and the evolutionary distant bacterium Escherichia coli. We propose that nanotubes represent a major form of bacterial communication in nature, providing a network for exchange of cellular molecules within and between species. PMID:21335240

  17. Bacterial infections.

    PubMed

    Gray, F

    1997-01-01

    The organisms that produce bacterial infections of the nervous system in tropical regions are similar to those existing in the rest of the world. However, because of poor socio-economic conditions in the former areas, preventing the implementation of appropriate prophylactic and therapeutic measures, the incidence and course of these diseases may vary. In this paper the neuropathological appearances of the main bacterial diseases are reviewed and the main differences between those occurring in developed and developing countries emphasized. Despite great efforts by governments and communities, tuberculosis still remains a scourge in many countries and leprosy has not been eradicated from earth. Earlier optimism that antibiotics could finally put an end to syphilis have been dashed and the disease still persists. Moreover, the explosion of AIDS not only has produced a recrudescence of many of these diseases, but has also changed their clinical and pathological presentation. PMID:9034570

  18. Physicians' strikes and the competing bases of physicians' moral obligations.

    PubMed

    MacDougall, D Robert

    2013-09-01

    Many authors have addressed the morality of physicians' strikes on the assumption that medical practice is morally different from other kinds of occupations. This article analyzes three prominent theoretical accounts that attempt to ground such special moral obligations for physicians--practice-based accounts, utilitarian accounts, and social contract accounts--and assesses their applicability to the problem of the morality of strikes. After critiquing these views, it offers a fourth view grounding special moral obligations in voluntary commitments, and explains why this is a preferable basis for understanding physicians' moral obligations in general and especially as pertaining to strikes. PMID:24199524

  19. Direct Measurement of Intracellular Pressure

    PubMed Central

    Petrie, Ryan J.; Koo, Hyun

    2014-01-01

    A method to directly measure the intracellular pressure of adherent, migrating cells is described in the Basic Protocol. This approach is based on the servo-null method where a microelectrode is introduced into the cell to directly measure the physical pressure of the cytoplasm. We also describe the initial calibration of the microelectrode as well as the application of the method to cells migrating inside three-dimensional (3D) extracellular matrix (ECM). PMID:24894836

  20. Importance of Branched-Chain Amino Acid Utilization in Francisella Intracellular Adaptation

    PubMed Central

    Gesbert, Gael; Ramond, Elodie; Tros, Fabiola; Dairou, Julien; Frapy, Eric; Barel, Monique

    2014-01-01

    Intracellular bacterial pathogens have adapted their metabolism to optimally utilize the nutrients available in infected host cells. We recently reported the identification of an asparagine transporter required specifically for cytosolic multiplication of Francisella. In the present work, we characterized a new member of the major super family (MSF) of transporters, involved in isoleucine uptake. We show that this transporter (here designated IleP) plays a critical role in intracellular metabolic adaptation of Francisella. Inactivation of IleP severely impaired intracellular F. tularensis subsp. novicida multiplication in all cell types tested and reduced bacterial virulence in the mouse model. To further establish the importance of the ileP gene in F. tularensis pathogenesis, we constructed a chromosomal deletion mutant of ileP (ΔFTL_1803) in the F. tularensis subsp. holarctica live vaccine strain (LVS). Inactivation of IleP in the F. tularensis LVS provoked comparable intracellular growth defects, confirming the critical role of this transporter in isoleucine uptake. The data presented establish, for the first time, the importance of isoleucine utilization for efficient phagosomal escape and cytosolic multiplication of Francisella and suggest that virulent F. tularensis subspecies have lost their branched-chain amino acid biosynthetic pathways and rely exclusively on dedicated uptake systems. This loss of function is likely to reflect an evolution toward a predominantly intracellular life style of the pathogen. Amino acid transporters should be thus considered major players in the adaptation of intracellular pathogens. PMID:25332124

  1. Sequestration of host metabolism by an intracellular pathogen.

    PubMed

    Gehre, Lena; Gorgette, Olivier; Perrinet, Stéphanie; Prevost, Marie-Christine; Ducatez, Mathieu; Giebel, Amanda M; Nelson, David E; Ball, Steven G; Subtil, Agathe

    2016-01-01

    For intracellular pathogens, residence in a vacuole provides a shelter against cytosolic host defense to the cost of limited access to nutrients. The human pathogen Chlamydia trachomatis grows in a glycogen-rich vacuole. How this large polymer accumulates there is unknown. We reveal that host glycogen stores shift to the vacuole through two pathways: bulk uptake from the cytoplasmic pool, and de novo synthesis. We provide evidence that bacterial glycogen metabolism enzymes are secreted into the vacuole lumen through type 3 secretion. Our data bring strong support to the following scenario: bacteria co-opt the host transporter SLC35D2 to import UDP-glucose into the vacuole, where it serves as substrate for de novo glycogen synthesis, through a remarkable adaptation of the bacterial glycogen synthase. Based on these findings we propose that parasitophorous vacuoles not only offer protection but also provide a microorganism-controlled metabolically active compartment essential for redirecting host resources to the pathogens. PMID:26981769

  2. Intracellular Calcium Channels in Protozoa

    PubMed Central

    Docampo, Roberto; Moreno, Silvia N.J.; Plattner, Helmut

    2014-01-01

    Ca2+-signaling pathways and intracellular Ca2+ channels are present in protozoa. Ancient origin of inositol 1,4,5-trisphosphate receptors (IP3Rs) and other intracellular channels predates the divergence of animals and fungi as evidenced by their presence in the choanoflagellate Monosiga brevicollis, the closest known relative to metazoans. The first protozoan IP3R cloned, from the ciliate Paramecium, displays strong sequence similarity to the rat type 3 IP3R. This ciliate has a large number of IP3- and ryanodine(Ry)-like receptors in 6 subfamilies suggesting the evolutionary adaptation to local requirements for an expanding diversification of vesicle trafficking. IP3Rs have also been functionally characterized in trypanosomatids, where they are essential for growth, differentiation, and establishment of infection. The presence of the mitochondrial calcium uniporter (MCU) in a number of protozoa indicates that mitochondrial regulation of Ca2+ signaling is also an early appearance in evolution, and contributed to the discovery of the molecular nature of this channel in mammalian cells. There is only sequence evidence for the occurrence of two-pore channels (TPCs), transient receptor potential Ca2+ channels (TRPCs) and intracellular mechanosensitive Ca2+-channels in Paramecium and in parasitic protozoa. PMID:24291099

  3. Intracellular calcium channels in protozoa.

    PubMed

    Docampo, Roberto; Moreno, Silvia N J; Plattner, Helmut

    2014-09-15

    Ca(2+)-signaling pathways and intracellular Ca(2+) channels are present in protozoa. Ancient origin of inositol 1,4,5-trisphosphate receptors (IP3Rs) and other intracellular channels predates the divergence of animals and fungi as evidenced by their presence in the choanoflagellate Monosiga brevicollis, the closest known relative to metazoans. The first protozoan IP3R cloned, from the ciliate Paramecium, displays strong sequence similarity to the rat type 3 IP3R. This ciliate has a large number of IP3- and ryanodine(Ry)-like receptors in six subfamilies suggesting the evolutionary adaptation to local requirements for an expanding diversification of vesicle trafficking. IP3Rs have also been functionally characterized in trypanosomatids, where they are essential for growth, differentiation, and establishment of infection. The presence of the mitochondrial calcium uniporter (MCU) in a number of protozoa indicates that mitochondrial regulation of Ca(2+) signaling is also an early appearance in evolution, and contributed to the discovery of the molecular nature of this channel in mammalian cells. There is only sequence evidence for the occurrence of two-pore channels (TPCs), transient receptor potential Ca(2+) channels (TRPCs) and intracellular mechanosensitive Ca(2+)-channels in Paramecium and in parasitic protozoa. PMID:24291099

  4. Microsporidia Are Natural Intracellular Parasites of the Nematode Caenorhabditis elegans

    PubMed Central

    Troemel, Emily R; Félix, Marie-Anne; Whiteman, Noah K; Barrière, Antoine; Ausubel, Frederick M

    2008-01-01

    For decades the soil nematode Caenorhabditis elegans has been an important model system for biology, but little is known about its natural ecology. Recently, C. elegans has become the focus of studies of innate immunity and several pathogens have been shown to cause lethal intestinal infections in C. elegans. However none of these pathogens has been shown to invade nematode intestinal cells, and no pathogen has been isolated from wild-caught C. elegans. Here we describe an intracellular pathogen isolated from wild-caught C. elegans that we show is a new species of microsporidia. Microsporidia comprise a large class of eukaryotic intracellular parasites that are medically and agriculturally important, but poorly understood. We show that microsporidian infection of the C. elegans intestine proceeds through distinct stages and is transmitted horizontally. Disruption of a conserved cytoskeletal structure in the intestine called the terminal web correlates with the release of microsporidian spores from infected cells, and appears to be part of a novel mechanism by which intracellular pathogens exit from infected cells. Unlike in bacterial intestinal infections, the p38 MAPK and insulin/insulin-like growth factor (IGF) signaling pathways do not appear to play substantial roles in resistance to microsporidian infection in C. elegans. We found microsporidia in multiple wild-caught isolates of Caenorhabditis nematodes from diverse geographic locations. These results indicate that microsporidia are common parasites of C. elegans in the wild. In addition, the interaction between C. elegans and its natural microsporidian parasites provides a system in which to dissect intracellular intestinal infection in vivo and insight into the diversity of pathogenic mechanisms used by intracellular microbes. PMID:19071962

  5. Bacterial pathogen manipulation of host membrane trafficking.

    PubMed

    Asrat, Seblewongel; de Jesús, Dennise A; Hempstead, Andrew D; Ramabhadran, Vinay; Isberg, Ralph R

    2014-01-01

    Pathogens use a vast number of strategies to alter host membrane dynamics. Targeting the host membrane machinery is important for the survival and pathogenesis of several extracellular, vacuolar, and cytosolic bacteria. Membrane manipulation promotes bacterial replication while suppressing host responses, allowing the bacterium to thrive in a hostile environment. This review provides a comprehensive summary of various strategies used by both extracellular and intracellular bacteria to hijack host membrane trafficking machinery. We start with mechanisms used by bacteria to alter the plasma membrane, delve into the hijacking of various vesicle trafficking pathways, and conclude by summarizing bacterial adaptation to host immune responses. Understanding bacterial manipulation of host membrane trafficking provides insights into bacterial pathogenesis and uncovers the molecular mechanisms behind various processes within a eukaryotic cell. PMID:25103867

  6. 7 CFR 400.166 - Obligations of the Corporation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... regulations under the Act published in chapter IV of 7 CFR. ... CORPORATION, DEPARTMENT OF AGRICULTURE GENERAL ADMINISTRATIVE REGULATIONS Reinsurance Agreement-Standards for Approval; Regulations for the 1997 and Subsequent Reinsurance Years § 400.166 Obligations of...

  7. 12 CFR 997.5 - Termination of the obligation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... April 15, 2030, will terminate when the aggregate actual quarterly payments made by the Banks exactly... first obligation of the REFCORP was issued and ends on April 15, 2030. (b) Date of the final...

  8. 12 CFR 997.5 - Termination of the obligation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... April 15, 2030, will terminate when the aggregate actual quarterly payments made by the Banks exactly... first obligation of the REFCORP was issued and ends on April 15, 2030. (b) Date of the final...

  9. 7 CFR 1488.12 - Coverage of bank obligations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Sales of Agricultural Commodities From Private Stocks Under CCC Export Credit Sales Program (GSM-5) Bank... obligation. (j) Collection of accounts receivable purchased under GSM-5 will be effected through the...

  10. 7 CFR 1488.12 - Coverage of bank obligations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Sales of Agricultural Commodities From Private Stocks Under CCC Export Credit Sales Program (GSM-5) Bank... obligation. (j) Collection of accounts receivable purchased under GSM-5 will be effected through the...

  11. 7 CFR 1488.12 - Coverage of bank obligations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Sales of Agricultural Commodities From Private Stocks Under CCC Export Credit Sales Program (GSM-5) Bank... obligation. (j) Collection of accounts receivable purchased under GSM-5 will be effected through the...

  12. 47 CFR 54.405 - Carrier obligation to offer Lifeline.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (CONTINUED) UNIVERSAL SERVICE Universal Service Support for Low-Income Consumers § 54.405 Carrier obligation... demonstrate continued eligibility within the 60-day time period. A carrier providing Lifeline service in...

  13. 47 CFR 54.405 - Carrier obligation to offer Lifeline.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) UNIVERSAL SERVICE Universal Service Support for Low-Income Consumers § 54.405 Carrier obligation... within the 60-day time period. A carrier providing Lifeline service in a state that has...

  14. The Ebola outbreak in Western Africa: ethical obligations for care.

    PubMed

    Yakubu, Aminu; Folayan, Morenike Oluwatoyin; Sani-Gwarzo, Nasir; Nguku, Patrick; Peterson, Kristin; Brown, Brandon

    2016-04-01

    The recent wave of the Ebola Virus Disease (EVD) in Western Africa and efforts to control the disease where the health system requires strengthening raises a number of ethical challenges for healthcare workers practicing in these countries. We discuss the implications of weak health systems for controlling EVD and limitations of the ethical obligation to provide care for patients with EVD using Nigeria as a case study. We highlight the right of healthcare workers to protection that should be obligatorily provided by the government. Where the national government cannot meet this obligation, healthcare workers only have a moral and not a professional obligation to provide care to patients with EVD. The national government also has an obligation to adequately compensate healthcare workers that become infected in the course of duty. Institutionalisation of policies that protect healthcare workers are required for effective control of the spread of highly contagious diseases like EVD in a timely manner. PMID:25205389

  15. 18 CFR 1314.6 - Obligations of TVA.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Obligations of TVA. 1314.6 Section 1314.6 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY BOOK-ENTRY PROCEDURES FOR TVA POWER SECURITIES ISSUED THROUGH THE FEDERAL RESERVE BANKS § 1314.6 Obligations of TVA. (a) Except in the case of a security...

  16. Antibodies protect against intracellular bacteria by Fc receptor-mediated lysosomal targeting.

    PubMed

    Joller, Nicole; Weber, Stefan S; Müller, Andreas J; Spörri, Roman; Selchow, Petra; Sander, Peter; Hilbi, Hubert; Oxenius, Annette

    2010-11-23

    The protective effect of antibodies (Abs) is generally attributed to neutralization or complement activation. Using Legionella pneumophila and Mycobacterium bovis bacillus Calmette-Guérin as a model, we discovered an additional mechanism of Ab-mediated protection effective against intracellular pathogens that normally evade lysosomal fusion. We show that Fc receptor (FcR) engagement by Abs, which can be temporally and spatially separated from bacterial infection, renders the host cell nonpermissive for bacterial replication and targets the pathogens to lysosomes. This process is strictly dependent on kinases involved in FcR signaling but not on host cell protein synthesis or protease activation. Based on these findings, we propose a mechanism whereby Abs and FcR engagement subverts the strategies by which intracellular bacterial pathogens evade lysosomal degradation. PMID:21048081

  17. Identification and antimicrobial susceptibility of obligate anaerobic bacteria from clinical samples of animal origin.

    PubMed

    Mayorga, Melissa; Rodríguez-Cavallini, Evelyn; López-Ureña, Diana; Barquero-Calvo, Elías; Quesada-Gómez, Carlos

    2015-12-01

    The etiology of veterinary infectious diseases has been the focus of considerable research, yet relatively little is known about the causative agents of anaerobic infections. Susceptibility studies have documented the emergence of antimicrobial resistance and indicate distinct differences in resistance patterns related to veterinary hospitals, geographic regions, and antibiotic-prescribing regimens. The aim of the present study was to identify the obligate anaerobic bacteria from veterinary clinical samples and to determinate the in vitro susceptibility to eight antimicrobials and their resistance-associated genes. 81 clinical specimens obtained from food-producing animals, pets and wild animals were examined to determine the relative prevalence of obligate anaerobic bacteria, and the species represented. Bacteroides spp, Prevotella spp and Clostridium spp represented approximately 80% of all anaerobic isolates. Resistance to metronidazole, clindamycin, tetracycline and fluoroquinolones was found in strains isolated from food-producing animals. Ciprofloxacin, enrofloxacin and cephalotin showed the highest resistance in all isolates. In 17%, 4% and 14% of tetracycline-resistant isolates, the resistance genes tetL, tetM and tetW were respectively amplified by PCR whereas in 4% of clindamycin-resistant strains the ermG gene was detected. 26% of the isolates were positive for cepA, while only 6% harbored the cfxA (resistance-conferring genes to beta-lactams). In this study, the obligate anaerobic bacteria from Costa Rica showed a high degree of resistance to most antimicrobials tested. Nevertheless, in the majority of cases this resistance was not related to the resistance acquired genes usually described in anaerobes. It is important to address and regulate the use of antimicrobials in the agricultural industry and the empirical therapy in anaerobic bacterial infections in veterinary medicine, especially since antibiotics and resistant bacteria can persist in the environment. PMID:26385434

  18. Spatially-resolved intracellular sensing of hydrogen peroxide in living cells

    PubMed Central

    Warren, Emilie A. K.; Netterfield, Tatiana S.; Sarkar, Saheli; Kemp, Melissa L.; Payne, Christine K.

    2015-01-01

    Understanding intracellular redox chemistry requires new tools for the site-specific visualization of intracellular oxidation. We have developed a spatially-resolved intracellular sensor of hydrogen peroxide, HyPer-Tau, for time-resolved imaging in live cells. This sensor consists of a hydrogen peroxide-sensing protein tethered to microtubules. We demonstrate the use of the HyPer-Tau sensor for three applications; dose-dependent response of human cells to exogenous hydrogen peroxide, a model immune response of mouse macrophages to stimulation by bacterial toxin, and a spatially-resolved response to localized delivery of hydrogen peroxide. These results demonstrate that HyPer-Tau can be used as an effective tool for tracking changes in spatially localized intracellular hydrogen peroxide and for future applications in redox signaling. PMID:26585385

  19. Intracellular parcel service: current issues in intracellular membrane trafficking.

    PubMed

    Herrmann, Johannes M; Spang, Anne

    2015-01-01

    Eukaryotic cells contain a multitude of membrane structures that are connected through a highly dynamic and complex exchange of their constituents. The vibrant instability of these structures challenges the classical view of defined, static compartments that are connected by different types of vesicles. Despite this astonishing complexity, proteins and lipids are accurately transported into the different intracellular membrane systems. Over the past few decades many factors have been identified that either mediate or regulate intracellular membrane trafficking. Like in a modern parcel sorting system of a logistics center, the cargo typically passes through several sequential sorting stations until it finally reaches the location that is specified by its individual address label. While each membrane system employs specific sets of factors, the transport processes typically operate on common principles. With the advent of genome- and proteome-wide screens, the availability of mutant collections, exciting new developments in microscope technology and sophisticated methods to study their dynamics, the future promises a broad and comprehensive picture of the processes by which eukaryotic cells sort their proteins. PMID:25702105

  20. Intense Transpositional Activity of Insertion Sequences in an Ancient Obligate Endosymbiont

    PubMed Central

    Pichon, Samuel; Ling, Alison; Pérez, Philippe; Delaunay, Carine; Vavre, Fabrice; Bouchon, Didier; Grève, Pierre

    2008-01-01

    The streamlined genomes of ancient obligate endosymbionts generally lack transposable elements, such as insertion sequences (IS). Yet, the genome of Wolbachia, one of the most abundant bacterial endosymbionts on Earth, is littered with IS. Such a paradox raises the question as to why there are so many ISs in the genome of this ancient endosymbiont. To address this question, we investigated IS transpositional activity in the unculturable Wolbachia by tracking the evolutionary dynamics and history of ISWpi1 elements. We show that 1) ISWpi1 is widespread in Wolbachia, being present in at least 55% of the 40 sampled strains, 2) ISWpi1 copies exhibit virtually identical nucleotide sequences both within and among Wolbachia genomes and possess an intact transposase gene, 3) individual ISWpi1 copies are differentially inserted among Wolbachia genomes, and 4) ISWpi1 occurs at variable copy numbers among Wolbachia genomes. Collectively, our results provide compelling evidence for intense ISWpi1 transpositional activity and frequent ISWpi1 horizontal transmission among strains during recent Wolbachia evolution. Thus, the genomes of ancient obligate endosymbionts can carry high loads of functional and transpositionally active transposable elements. Our results also indicate that Wolbachia genomes have experienced multiple and temporally distinct ISWpi1 invasions during their evolutionary history. Such recurrent exposition to new IS invasions may explain, at least partly, the unusually high density of transposable elements found in the genomes of Wolbachia endosymbionts. PMID:18562339

  1. Bacterial Games

    NASA Astrophysics Data System (ADS)

    Frey, Erwin; Reichenbach, Tobias

    Microbial laboratory communities have become model systems for studying the complex interplay between nonlinear dynamics of evolutionary selection forces, stochastic fluctuations arising from the probabilistic nature of interactions, and spatial organization. Major research goals are to identify and understand mechanisms that ensure viability of microbial colonies by allowing for species diversity, cooperative behavior and other kinds of "social" behavior. A synthesis of evolutionary game theory, nonlinear dynamics, and the theory of stochastic processes provides the mathematical tools and conceptual framework for a deeper understanding of these ecological systems. We give an introduction to the modern formulation of these theories and illustrate their effectiveness, focusing on selected examples of microbial systems. Intrinsic fluctuations, stemming from the discreteness of individuals, are ubiquitous, and can have important impact on the stability of ecosystems. In the absence of speciation, extinction of species is unavoidable, may, however, take very long times. We provide a general concept for defining survival and extinction on ecological time scales. Spatial degrees of freedom come with a certain mobility of individuals. When the latter is sufficiently high, bacterial community structures can be understood through mapping individual-based models, in a continuum approach, onto stochastic partial differential equations. These allow progress using methods of nonlinear dynamics such as bifurcation analysis and invariant manifolds. We conclude with a perspective on the current challenges in quantifying bacterial pattern formation, and how this might have an impact on fundamental research in nonequilibrium physics .

  2. Investigating interference with apoptosis induction by bacterial proteins.

    PubMed

    Niu, Hua; Rikihisa, Yasuko

    2014-01-01

    The modulation of host cell apoptosis by bacterial pathogens is critical for their intracellular survival. Several intracellular bacteria achieve this by secreting proteins that interact with apoptosis pathways to inhibit host cell apoptosis. Anaplasma phagocytophilum, which causes human granulocytic anaplasmosis, is such bacterium. The protein Ats-1, translocated from A. phagocytophilum by the bacterial type IV secretion system, localizes to host cell mitochondria, and interferes with apoptosis induction. In this chapter, we present a protocol applied to investigate an anti-apoptotic effect of Ats-1. PMID:25172281

  3. Pharmacology of intracellular signalling pathways

    PubMed Central

    Nahorski, Stefan R

    2006-01-01

    This article provides a brief and somewhat personalized review of the dramatic developments that have occurred over the last 45 years in our understanding of intracellular signalling pathways associated with G-protein-coupled receptor activation. Signalling via cyclic AMP, the phosphoinositides and Ca2+ is emphasized and these systems have already been revealed as new pharmacological targets. The therapeutic benefits of most of such targets are, however, yet to be realized, but it is certain that the discipline of pharmacology needs to widen its boundaries to meet these challenges in the future. PMID:16402119

  4. Mechanisms of Obligatory Intracellular Infection with Anaplasma phagocytophilum

    PubMed Central

    Rikihisa, Yasuko

    2011-01-01

    Summary: Anaplasma phagocytophilum persists in nature by cycling between mammals and ticks. Human infection by the bite of an infected tick leads to a potentially fatal emerging disease called human granulocytic anaplasmosis. A. phagocytophilum is an obligatory intracellular bacterium that replicates inside mammalian granulocytes and the salivary gland and midgut cells of ticks. A. phagocytophilum evolved the remarkable ability to hijack the regulatory system of host cells. A. phagocytophilum alters vesicular traffic to create an intracellular membrane-bound compartment that allows replication in seclusion from lysosomes. The bacterium downregulates or actively inhibits a number of innate immune responses of mammalian host cells, and it upregulates cellular cholesterol uptake to acquire cholesterol for survival. It also upregulates several genes critical for the infection of ticks, and it prolongs tick survival at freezing temperatures. Several host factors that exacerbate infection have been identified, including interleukin-8 (IL-8) and cholesterol. Host factors that overcome infection include IL-12 and gamma interferon (IFN-γ). Two bacterial type IV secretion effectors and several bacterial proteins that associate with inclusion membranes have been identified. An understanding of the molecular mechanisms underlying A. phagocytophilum infection will foster the development of creative ideas to prevent or treat this emerging tick-borne disease. PMID:21734244

  5. Intracellular Bacteria Encode Inhibitory SNARE-Like Proteins

    PubMed Central

    Paumet, Fabienne; Wesolowski, Jordan; Garcia-Diaz, Alejandro; Delevoye, Cedric; Aulner, Nathalie; Shuman, Howard A.; Subtil, Agathe; Rothman, James E.

    2009-01-01

    Pathogens use diverse molecular machines to penetrate host cells and manipulate intracellular vesicular trafficking. Viruses employ glycoproteins, functionally and structurally similar to the SNARE proteins, to induce eukaryotic membrane fusion. Intracellular pathogens, on the other hand, need to block fusion of their infectious phagosomes with various endocytic compartments to escape from the degradative pathway. The molecular details concerning the mechanisms underlying this process are lacking. Using both an in vitro liposome fusion assay and a cellular assay, we showed that SNARE-like bacterial proteins block membrane fusion in eukaryotic cells by directly inhibiting SNARE-mediated membrane fusion. More specifically, we showed that IncA and IcmG/DotF, two SNARE-like proteins respectively expressed by Chlamydia and Legionella, inhibit the endocytic SNARE machinery. Furthermore, we identified that the SNARE-like motif present in these bacterial proteins encodes the inhibitory function. This finding suggests that SNARE-like motifs are capable of specifically manipulating membrane fusion in a wide variety of biological environments. Ultimately, this motif may have been selected during evolution because it is an efficient structural motif for modifying eukaryotic membrane fusion and thus contribute to pathogen survival. PMID:19823575

  6. Review: Intracardiac intracellular angiotensin system in diabetes

    PubMed Central

    Kumar, Rajesh; Yong, Qian Chen; Thomas, Candice M.

    2012-01-01

    The renin-angiotensin system (RAS) has mainly been categorized as a circulating and a local tissue RAS. A new component of the local system, known as the intracellular RAS, has recently been described. The intracellular RAS is defined as synthesis and action of ANG II intracellularly. This RAS appears to differ from the circulating and the local RAS, in terms of components and the mechanism of action. These differences may alter treatment strategies that target the RAS in several pathological conditions. Recent work from our laboratory has demonstrated significant upregulation of the cardiac, intracellular RAS in diabetes, which is associated with cardiac dysfunction. Here, we have reviewed evidence supporting an intracellular RAS in different cell types, ANG II's actions in cardiac cells, and its mechanism of action, focusing on the intracellular cardiac RAS in diabetes. We have discussed the significance of an intracellular RAS in cardiac pathophysiology and implications for potential therapies. PMID:22170614

  7. 30 CFR 585.901 - When do I accrue decommissioning obligations?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false When do I accrue decommissioning obligations... Decommissioning Decommissioning Obligations and Requirements § 585.901 When do I accrue decommissioning obligations? You accrue decommissioning obligations when you are or become a lessee or grant holder, and...

  8. 30 CFR 285.901 - When do I accrue decommissioning obligations?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false When do I accrue decommissioning obligations... OUTER CONTINENTAL SHELF Decommissioning Decommissioning Obligations and Requirements § 285.901 When do I accrue decommissioning obligations? You accrue decommissioning obligations when you are or become...

  9. 30 CFR 250.1701 - Who must meet the decommissioning obligations in this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Who must meet the decommissioning obligations... SHELF Decommissioning Activities General § 250.1701 Who must meet the decommissioning obligations in... meeting decommissioning obligations for facilities on leases, including the obligations related to...

  10. 30 CFR 285.901 - When do I accrue decommissioning obligations?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When do I accrue decommissioning obligations... Decommissioning Decommissioning Obligations and Requirements § 285.901 When do I accrue decommissioning obligations? You accrue decommissioning obligations when you are or become a lessee or grant holder, and...

  11. 30 CFR 250.1701 - Who must meet the decommissioning obligations in this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Who must meet the decommissioning obligations... SHELF Decommissioning Activities General § 250.1701 Who must meet the decommissioning obligations in... meeting decommissioning obligations for facilities on leases, including the obligations related to...

  12. 30 CFR 585.901 - When do I accrue decommissioning obligations?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false When do I accrue decommissioning obligations... Decommissioning Decommissioning Obligations and Requirements § 585.901 When do I accrue decommissioning obligations? You accrue decommissioning obligations when you are or become a lessee or grant holder, and...

  13. 30 CFR 250.1701 - Who must meet the decommissioning obligations in this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Who must meet the decommissioning obligations... SHELF Decommissioning Activities General § 250.1701 Who must meet the decommissioning obligations in... meeting decommissioning obligations for facilities on leases, including the obligations related to...

  14. 30 CFR 585.901 - When do I accrue decommissioning obligations?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false When do I accrue decommissioning obligations..., COPs and GAPs Decommissioning Obligations and Requirements § 585.901 When do I accrue decommissioning obligations? You accrue decommissioning obligations when you are or become a lessee or grant holder, and...

  15. Microsporidia: Eukaryotic Intracellular Parasites Shaped by Gene Loss and Horizontal Gene Transfers.

    PubMed

    Corradi, Nicolas

    2015-01-01

    Microsporidia are eukaryotic parasites of many animals that appear to have adapted to an obligate intracellular lifestyle by modifying the morphology and content of their cells. Living inside other cells, they have lost many, or all, metabolic functions, resulting in genomes that are always gene poor and often very small. The minute content of microsporidian genomes led many to assume that these parasites are biochemically static and uninteresting. However, recent studies have demonstrated that these organisms can be surprisingly complex and dynamic. In this review I detail the most significant recent advances in microsporidian genomics and discuss how these have affected our understanding of many biological aspects of these peculiar eukaryotic intracellular pathogens. PMID:26195306

  16. Emancipating Chlamydia: Advances in the Genetic Manipulation of a Recalcitrant Intracellular Pathogen.

    PubMed

    Bastidas, Robert J; Valdivia, Raphael H

    2016-06-01

    Chlamydia species infect millions of individuals worldwide and are important etiological agents of sexually transmitted disease, infertility, and blinding trachoma. Historically, the genetic intractability of this intracellular pathogen has hindered the molecular dissection of virulence factors contributing to its pathogenesis. The obligate intracellular life cycle of Chlamydia and restrictions on the use of antibiotics as selectable markers have impeded the development of molecular tools to genetically manipulate these pathogens. However, recent developments in the field have resulted in significant gains in our ability to alter the genome of Chlamydia, which will expedite the elucidation of virulence mechanisms. In this review, we discuss the challenges affecting the development of molecular genetic tools for Chlamydia and the work that laid the foundation for recent advancements in the genetic analysis of this recalcitrant pathogen. PMID:27030552

  17. Forced Resurgence and Targeting of Intracellular Uropathogenic Escherichia coli Reservoirs

    PubMed Central

    Blango, Matthew G.; Ott, Elizabeth M.; Erman, Andreja; Veranic, Peter; Mulvey, Matthew A.

    2014-01-01

    Intracellular quiescent reservoirs of uropathogenic Escherichia coli (UPEC), which can seed the bladder mucosa during the acute phase of a urinary tract infection (UTI), are protected from antibiotic treatments and are extremely difficult to eliminate. These reservoirs are a potential source for recurrent UTIs that affect millions annually. Here, using murine infection models and the bladder cell exfoliant chitosan, we demonstrate that intracellular UPEC populations shift within the stratified layers of the urothelium during the course of a UTI. Following invasion of the terminally differentiated superficial layer of epithelial cells that line the bladder lumen, UPEC can multiply and disseminate, eventually establishing reservoirs within underlying immature host cells. If given access, UPEC can invade the superficial and immature bladder cells equally well. As infected immature host cells differentiate and migrate towards the apical surface of the bladder, UPEC can reinitiate growth and discharge into the bladder lumen. By inducing the exfoliation of the superficial layers of the urothelium, chitosan stimulates rapid regenerative processes and the reactivation and efflux of quiescent intracellular UPEC reservoirs. When combined with antibiotics, chitosan treatment significantly reduces bacterial loads within the bladder and may therefore be of therapeutic value to individuals with chronic, recurrent UTIs. PMID:24667805

  18. Lineage-Specific Patterns of Genome Deterioration in Obligate Symbionts of Sharpshooter Leafhoppers

    PubMed Central

    Bennett, Gordon M.; McCutcheon, John P.; McDonald, Bradon R.; Moran, Nancy A.

    2016-01-01

    Plant sap-feeding insects (Hemiptera) rely on obligate bacterial symbionts that provision nutrients. Some of these symbionts are ancient and have evolved tiny genomes, whereas others are younger and retain larger, dynamic genomes. Baumannia cicadellinicola, an obligate symbiont of sharpshooter leafhoppers, is derived from a relatively recent symbiont replacement. To better understand evolutionary decay of genomes, we compared Baumannia from three host species. A newly sequenced genome for Baumannia from the green sharpshooter (B-GSS) was compared with genomes of Baumannia from the blue-green sharpshooter (B-BGSS, 759 kilobases [kb]) and from the glassy-winged sharpshooter (B-GWSS, 680 kb). B-GSS has the smallest Baumannia genome sequenced to date (633 kb), with only three unique genes, all involved in membrane function. It has lost nearly all pathways involved in vitamin and cofactor synthesis, as well as amino acid biosynthetic pathways that are redundant with pathways of the host or the symbiotic partner, Sulcia muelleri. The entire biosynthetic pathway for methionine is eliminated, suggesting that methionine has become a dietary requirement for hosts. B-GSS and B-BGSS share 33 genes involved in bacterial functions (e.g., cell division, membrane synthesis, metabolite transport, etc.) that are lost from the more distantly related B-GWSS and most other tiny genome symbionts. Finally, pairwise divergence estimates indicate that B-GSS has experienced a lineage-specific increase in substitution rates. This increase correlates with accelerated protein-level changes and widespread gene loss. Thus, the mode and tempo of genome reduction vary widely among symbiont lineages and result in wide variation in metabolic capabilities across hosts. PMID:26260652

  19. Interactions between Autophagy and Bacterial Toxins: Targets for Therapy?

    PubMed Central

    Mathieu, Jacques

    2015-01-01

    Autophagy is a physiological process involved in defense mechanisms for clearing intracellular bacteria. The autophagic pathway is finely regulated and bacterial toxins interact with this process in a complex manner. Bacterial toxins also interact significantly with many biochemical processes. Evaluations of the effects of bacterial toxins, such as endotoxins, pore-forming toxins and adenylate cyclases, on autophagy could support the development of new strategies for counteracting bacterial pathogenicity. Treatment strategies could focus on drugs that enhance autophagic processes to improve the clearance of intracellular bacteria. However, further in vivo studies are required to decipher the upregulation of autophagy and potential side effects limiting such approaches. The capacity of autophagy activation strategies to improve the outcome of antibiotic treatment should be investigated in the future. PMID:26248079

  20. Bacterial Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Lauga, Eric

    2016-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells, yet they represent the bulk of the world's biomass and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micrometer scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically complex environments. Using hydrodynamics as an organizing framework, I review the biomechanics of bacterial motility and look ahead to future challenges.

  1. Amoebal Endosymbiont Neochlamydia Genome Sequence Illuminates the Bacterial Role in the Defense of the Host Amoebae against Legionella pneumophila

    PubMed Central

    Ishida, Kasumi; Sekizuka, Tsuyoshi; Hayashida, Kyoko; Matsuo, Junji; Takeuchi, Fumihiko; Kuroda, Makoto; Nakamura, Shinji; Yamazaki, Tomohiro; Yoshida, Mitsutaka; Takahashi, Kaori; Nagai, Hiroki; Sugimoto, Chihiro; Yamaguchi, Hiroyuki

    2014-01-01

    Previous work has shown that the obligate intracellular amoebal endosymbiont Neochlamydia S13, an environmental chlamydia strain, has an amoebal infection rate of 100%, but does not cause amoebal lysis and lacks transferability to other host amoebae. The underlying mechanism for these observations remains unknown. In this study, we found that the host amoeba could completely evade Legionella infection. The draft genome sequence of Neochlamydia S13 revealed several defects in essential metabolic pathways, as well as unique molecules with leucine-rich repeats (LRRs) and ankyrin domains, responsible for protein-protein interaction. Neochlamydia S13 lacked an intact tricarboxylic acid cycle and had an incomplete respiratory chain. ADP/ATP translocases, ATP-binding cassette transporters, and secretion systems (types II and III) were well conserved, but no type IV secretion system was found. The number of outer membrane proteins (OmcB, PomS, 76-kDa protein, and OmpW) was limited. Interestingly, genes predicting unique proteins with LRRs (30 genes) or ankyrin domains (one gene) were identified. Furthermore, 33 transposases were found, possibly explaining the drastic genome modification. Taken together, the genomic features of Neochlamydia S13 explain the intimate interaction with the host amoeba to compensate for bacterial metabolic defects, and illuminate the role of the endosymbiont in the defense of the host amoebae against Legionella infection. PMID:24747986

  2. The Effect of Bacteriophage Preparations on Intracellular Killing of Bacteria by Phagocytes

    PubMed Central

    Jończyk-Matysiak, Ewa; Łusiak-Szelachowska, Marzanna; Kłak, Marlena; Bubak, Barbara; Międzybrodzki, Ryszard; Weber-Dąbrowska, Beata; Żaczek, Maciej; Fortuna, Wojciech; Rogóż, Paweł; Letkiewicz, Sławomir; Szufnarowski, Krzysztof; Górski, Andrzej

    2015-01-01

    Intracellular killing of bacteria is one of the fundamental mechanisms against invading pathogens. Impaired intracellular killing of bacteria by phagocytes may be the reason of chronic infections and may be caused by antibiotics or substances that can be produced by some bacteria. Therefore, it was of great practical importance to examine whether phage preparations may influence the process of phagocyte intracellular killing of bacteria. It may be important especially in the case of patients qualified for experimental phage therapy (approximately half of the patients with chronic bacterial infections have their immunity impaired). Our analysis included 51 patients with chronic Gram-negative and Gram-positive bacterial infections treated with phage preparations at the Phage Therapy Unit in Wroclaw. The aim of the study was to investigate the effect of experimental phage therapy on intracellular killing of bacteria by patients' peripheral blood monocytes and polymorphonuclear neutrophils. We observed that phage therapy does not reduce patients' phagocytes' ability to kill bacteria, and it does not affect the activity of phagocytes in patients with initially reduced ability to kill bacteria intracellularly. Our results suggest that experimental phage therapy has no significant adverse effects on the bactericidal properties of phagocytes, which confirms the safety of the therapy. PMID:26783541

  3. Identification of a Novel Small Non-Coding RNA Modulating the Intracellular Survival of Brucella melitensis

    PubMed Central

    Wang, Yufei; Ke, Yuehua; Xu, Jie; Wang, Ligui; Wang, Tongkun; Liang, Hui; Zhang, Wei; Gong, Chunli; Yuan, Jiuyun; Zhuang, Yubin; An, Chang; Lei, Shuangshuang; Du, Xinying; Wang, Zhoujia; Li, Wenna; Yuan, Xitong; Huang, Liuyu; Yang, Xiaoli; Chen, Zeliang

    2015-01-01

    Bacterial small non-coding RNAs (sRNAs) are gene expression modulators respond to environmental changes, stressful conditions, and pathogenesis. In this study, by using a combined bioinformatic and experimental approach, eight novel sRNA genes were identified in intracellular pathogen Brucella melitensis. BSR0602, one sRNA that was highly induced in stationary phase, was further examined and found to modulate the intracellular survival of B. melitensis. BSR0602 was present at very high levels in vitro under stresses similar to those encountered during infection in host macrophages. Furthermore, BSR0602 was found to be highly expressed in the spleens of infected mice, suggesting its potential role in the control of pathogenesis. BSR0602 targets the mRNAs coding for gntR, a global transcriptional regulator, which is required for B. melitensis virulence. Overexpression of BSR0602 results in distinct reduction in the gntR mRNA level. B. melitensis with high level of BSR0602 is defective in bacteria intracellular survival in macrophages and defective in growth in the spleens of infected mice. Therefore, BSR0602 may directly inhibit the expression of gntR, which then impairs Brucellae intracellular survival and contributes to Brucella infection. Our findings suggest that BSR0602 is responsible for bacterial adaptation to stress conditions and thus modulate B. melitensis intracellular survival. PMID:25852653

  4. What are the public obligations to AIDS patients?

    PubMed

    Kelley, David

    2002-01-01

    The operating assumption in most discussions of health policy is that government has some responsibility for the health of its citizens and that it may legitimately tax, subsidize, and regulate its citizens in the exercise of that responsibility. On this assumption, public obligations to HIV/AIDS patients are a function of their needs in relationship to other health needs. This paper challenges the operating assumption by arguing that it cannot be grounded in the obligations that individuals have to each other. The paper rests on its own assumption: the moral theory of individualism. On this theory, individuals are ends in themselves who have the right to choose their own actions and uses of their resources; they do not have unchosen obligations to help others. In regard to HIV/AIDS patients, consequently, individuals have no duty to help, nor any other obligation beyond that of respecting their rights; and there is no valid basis for government regulations or subsidies on their behalf. The paper argues against the two approaches commonly used to defend a more expansive view of individual obligations and the role of government. The first is the assumption of welfare rights to goods and services; the second is the assumption that distributive justice requires some redistribution of health care resources. PMID:15971567

  5. [THE COMPARATIVE ANALYSIS OF INFORMATION VALUE OF MAIN CLINICAL CRITERIA USED TO DIAGNOSE OF BACTERIAL VAGINOSIS].

    PubMed

    Tsvetkova, A V; Murtazina, Z A; Markusheva, T V; Mavzutov, A R

    2015-05-01

    The bacterial vaginosis is one of the most frequent causes of women visiting gynecologist. The diagnostics of bacterial vaginosis is predominantly based on Amsel criteria (1983). Nowadays, the objectivity of these criteria is disputed more often. The analysis of excretion of mucous membranes of posterolateral fornix of vagina was applied to 640 women with clinical diagnosis bacterial vaginosis. The application of light microscopy to mounts of excretion confirmed in laboratory way the diagnosis of bacterial vaginosis in 100 (15.63%) women. The complaints of burning and unpleasant smell and the Amsel criterion of detection of "key cells" against the background of pH > 4.5 were established as statistically significant for bacterial vaginosis. According study data, the occurrence of excretions has no statistical reliable obligation for differentiation of bacterial vaginosis form other inflammatory pathological conditions of female reproductive sphere. At the same time, detection of "key cells" in mount reliably correlated with bacterial vaginosis. PMID:26470439

  6. Palladium-mediated intracellular chemistry

    NASA Astrophysics Data System (ADS)

    Yusop, Rahimi M.; Unciti-Broceta, Asier; Johansson, Emma M. V.; Sánchez-Martín, Rosario M.; Bradley, Mark

    2011-03-01

    Many important intracellular biochemical reactions are modulated by transition metals, typically in the form of metalloproteins. The ability to carry out selective transformations inside a cell would allow researchers to manipulate or interrogate innumerable biological processes. Here, we show that palladium nanoparticles trapped within polystyrene microspheres can enter cells and mediate a variety of Pd0-catalysed reactions, such as allylcarbamate cleavage and Suzuki-Miyaura cross-coupling. The work provides the basis for the customization of heterogeneous unnatural catalysts as tools to carry out artificial chemistries within cells. Such in cellulo synthesis has potential for a plethora of applications ranging from cellular labelling to synthesis of modulators or inhibitors of cell function.

  7. Interferon-gamma-activated primary enterocytes inhibit Toxoplasma gondii replication: a role for intracellular iron.

    PubMed Central

    Dimier, I H; Bout, D T

    1998-01-01

    Toxoplasma gondii is an obligate intracellular parasite that infects a wide variety of nucleated cells in its numerous intermediate hosts including man. The oral route is the natural portal of entry of T. gondii. Ingested organisms are released from cysts or oocysts within the gastrointestinal tract and initially invade the intestinal epithelium. We show that T. gondii invades and proliferates in cultured primary rat enterocytes, obtained with an original procedure. Activation of the enterocytes with rat recombinant interferon-gamma (IFN-gamma) inhibits T. gondii replication, the inhibition being dose dependent. Neither nitrogen and oxygen derivatives nor tryptophan starvation appear to be involved in the inhibition of parasite replication by IFN-gamma. Experiments using Fe2+ salt, carrier and chelator indicate that intracellular T. gondii replication is iron dependent, suggesting that IFN-gamma-treated enterocytes inhibit T. gondii replication by limiting the availability of intracellular iron to the parasite. Our data show that enterocytes probably play a major role on mucosal surfaces as a first line of defence against this coccidia, and possibly other pathogens, through an immune mechanism. The results suggest that limiting the availability of iron could represent a broad antimicrobial mechanism through which the activated enterocytes exert control over intracellular pathogens. PMID:9767436

  8. INTRACELLULAR SIGNALING BY BILE ACIDS

    PubMed Central

    Anwer, Mohammed Sawkat

    2014-01-01

    Bile acids, synthesized from cholesterol, are known to produce beneficial as well as toxic effects in the liver. The beneficial effects include choleresis, immunomodulation, cell survival, while the toxic effects include cholestasis, apoptosis and cellular toxicity. It is believed that bile acids produce many of these effects by activating intracellular signaling pathways. However, it has been a challenge to relate intracellular signaling to specific and at times opposing effects of bile acids. It is becoming evident that bile acids produce different effects by activating different isoforms of phosphoinositide 3-kinase (PI3K), Protein kinase Cs (PKCs), and mitogen activated protein kinases (MAPK). Thus, the apoptotic effect of bile acids may be mediated via PI3K-110γ, while cytoprotection induce by cAMP-GEF pathway involves activation of PI3K-p110α/β isoforms. Atypical PKCζ may mediate beneficial effects and nPKCε may mediate toxic effects, while cPKCα and nPKCδ may be involved in both beneficial and toxic effects of bile acids. The opposing effects of nPKCδ activation may depend on nPKCδ phosphorylation site(s). Activation of ERK1/2 and JNK1/2 pathway appears to mediate beneficial and toxic effects, respectively, of bile acids. Activation of p38α MAPK and p38β MAPK may mediate choleretic and cholestatic effects, respectively, of bile acids. Future studies clarifying the isoform specific effects on bile formation should allow us to define potential therapeutic targets in the treatment of cholestatic disorders. PMID:25378891

  9. In vitro and intracellular activities of peptide deformylase inhibitor GSK1322322 against Legionella pneumophila isolates.

    PubMed

    Dubois, Jacques; Dubois, Maïtée; Martel, Jean-François; Aubart, Kelly; Butler, Deborah

    2015-01-01

    GSK1322322, a novel peptide deformylase inhibitor currently in development as an oral and intravenous agent for the treatment of hospitalized community-acquired bacterial pneumonia, showed poor in vitro activity against a panel of 50 Legionella pneumophila strains, with MICs ranging from 1 to 16 μg/ml and an MIC90 of 16 μg/ml, but very potent intracellular activity, with the minimum extracellular concentrations capable of inhibiting intracellular proliferation (MIECs) ranging from 0.12 to 2 μg/ml and 98% of the strains being inhibited by concentrations of ≤ 1 μg/ml. PMID:25348534

  10. A detailed view of the intracellular transcriptome of Listeria monocytogenes in murine macrophages using RNA-seq

    PubMed Central

    Schultze, Tilman; Hilker, Rolf; Mannala, Gopala K.; Gentil, Katrin; Weigel, Markus; Farmani, Neda; Windhorst, Anita C.; Goesmann, Alexander; Chakraborty, Trinad; Hain, Torsten

    2015-01-01

    Listeria monocytogenes is a bacterial pathogen and causative agent for the foodborne infection listeriosis, which is mainly a threat for pregnant, elderly, or immunocompromised individuals. Due to its ability to invade and colonize diverse eukaryotic cell types including cells from invertebrates, L. monocytogenes has become a well-established model organism for intracellular growth. Almost 10 years ago, we and others presented the first whole-genome microarray-based intracellular transcriptome of L. monocytogenes. With the advent of newer technologies addressing transcriptomes in greater detail, we revisit this work, and analyze the intracellular transcriptome of L. monocytogenes during growth in murine macrophages using a deep sequencing based approach. We detected 656 differentially expressed genes of which 367 were upregulated during intracellular growth in macrophages compared to extracellular growth in Brain Heart Infusion broth. This study confirmed ∼64% of all regulated genes previously identified by microarray analysis. Many of the regulated genes that were detected in the current study involve transporters for various metals, ions as well as complex sugars such as mannose. We also report changes in antisense transcription, especially upregulations during intracellular bacterial survival. A notable finding was the detection of regulatory changes for a subset of temperate A118-like prophage genes, thereby shedding light on the transcriptional profile of this bacteriophage during intracellular growth. In total, our study provides an updated genome-wide view of the transcriptional landscape of L. monocytogenes during intracellular growth and represents a rich resource for future detailed analysis. PMID:26579105

  11. Bacterial vaginosis.

    PubMed Central

    Spiegel, C A

    1991-01-01

    Bacterial vaginosis (BV) is the most common of the vaginitides affecting women of reproductive age. It appears to be due to an alteration in the vaginal ecology by which Lactobacillus spp., the predominant organisms in the healthy vagina, are replaced by a mixed flora including Prevotella bivia, Prevotella disiens, Porphyromonas spp., Mobiluncus spp., and Peptostreptococcus spp. All of these organisms except Mobiluncus spp. are also members of the endogenous vaginal flora. While evidence from treatment trials does not support the notion that BV is sexually transmitted, recent studies have shown an increased risk associated with multiple sexual partners. It has also been suggested that the pathogenesis of BV may be similar to that of urinary tract infections, with the rectum serving as a reservoir for some BV-associated flora. The organisms associated with BV have also been recognized as agents of female upper genital tract infection, including pelvic inflammatory disease, and the syndrome BV has been associated with adverse outcome of pregnancy, including premature rupture of membranes, chorioamnionitis, and fetal loss; postpartum endometritis; cuff cellulitis; and urinary tract infections. The mechanisms by which the BV-associated flora causes the signs of BV are not well understood, but a role for H2O2-producing Lactobacillus spp. in protecting against colonization by catalase-negative anaerobic bacteria has been recognized. These and other aspects of BV are reviewed. PMID:1747864

  12. Environmental and safety obligations of the Chemical Weapons Convention

    SciTech Connect

    Tanzman, E.A.

    1994-04-07

    Among its many unique and precedent-setting provisions, the Chemical Weapons Convention (CWC) includes important requirements for States Parties to protect the public safety and the environment in the course of carrying out the treaty. These obligations will apply to the destruction of chemical weapons, of former chemical weapons production facilities, and to other activities under the Convention such as the verification scheme. This morning, I will briefly discuss the Convention`s safety and environmental obligations, concentrating on their effects in this country as the United States chemical weapons stockpile is destroyed.

  13. Linking the Transcriptional Profiles and the Physiological States of Mycobacterium tuberculosis during an Extended Intracellular Infection

    PubMed Central

    Rohde, Kyle H.; Veiga, Diogo F. T.; Caldwell, Shannon; Balázsi, Gábor; Russell, David G.

    2012-01-01

    Intracellular pathogens such as Mycobacterium tuberculosis have evolved strategies for coping with the pressures encountered inside host cells. The ability to coordinate global gene expression in response to environmental and internal cues is one key to their success. Prolonged survival and replication within macrophages, a key virulence trait of M. tuberculosis, requires dynamic adaptation to diverse and changing conditions within its phagosomal niche. However, the physiological adaptations during the different phases of this infection process remain poorly understood. To address this knowledge gap, we have developed a multi-tiered approach to define the temporal patterns of gene expression in M. tuberculosis in a macrophage infection model that extends from infection, through intracellular adaptation, to the establishment of a productive infection. Using a clock plasmid to measure intracellular replication and death rates over a 14-day infection and electron microscopy to define bacterial integrity, we observed an initial period of rapid replication coupled with a high death rate. This was followed by period of slowed growth and enhanced intracellular survival, leading finally to an extended period of net growth. The transcriptional profiles of M. tuberculosis reflect these physiological transitions as the bacterium adapts to conditions within its host cell. Finally, analysis with a Transcriptional Regulatory Network model revealed linked genetic networks whereby M. tuberculosis coordinates global gene expression during intracellular survival. The integration of molecular and cellular biology together with transcriptional profiling and systems analysis offers unique insights into the host-driven responses of intracellular pathogens such as M. tuberculosis. PMID:22737072

  14. The Chlamydia psittaci Genome: A Comparative Analysis of Intracellular Pathogens

    PubMed Central

    Saluz, Hans Peter

    2012-01-01

    Background Chlamydiaceae are a family of obligate intracellular pathogens causing a wide range of diseases in animals and humans, and facing unique evolutionary constraints not encountered by free-living prokaryotes. To investigate genomic aspects of infection, virulence and host preference we have sequenced Chlamydia psittaci, the pathogenic agent of ornithosis. Results A comparison of the genome of the avian Chlamydia psittaci isolate 6BC with the genomes of other chlamydial species, C. trachomatis, C. muridarum, C. pneumoniae, C. abortus, C. felis and C. caviae, revealed a high level of sequence conservation and synteny across taxa, with the major exception of the human pathogen C. trachomatis. Important differences manifest in the polymorphic membrane protein family specific for the Chlamydiae and in the highly variable chlamydial plasticity zone. We identified a number of psittaci-specific polymorphic membrane proteins of the G family that may be related to differences in host-range and/or virulence as compared to closely related Chlamydiaceae. We calculated non-synonymous to synonymous substitution rate ratios for pairs of orthologous genes to identify putative targets of adaptive evolution and predicted type III secreted effector proteins. Conclusions This study is the first detailed analysis of the Chlamydia psittaci genome sequence. It provides insights in the genome architecture of C. psittaci and proposes a number of novel candidate genes mostly of yet unknown function that may be important for pathogen-host interactions. PMID:22506068

  15. Bacterial concrete

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Venkataswamy; Ramesh, K. P.; Bang, S. S.

    2001-04-01

    Cracks in concrete are inevitable and are one of the inherent weaknesses of concrete. Water and other salts seep through these cracks, corrosion initiates, and thus reduces the life of concrete. So there was a need to develop an inherent biomaterial, a self-repairing material which can remediate the cracks and fissures in concrete. Bacterial concrete is a material, which can successfully remediate cracks in concrete. This technique is highly desirable because the mineral precipitation induced as a result of microbial activities is pollution free and natural. As the cell wall of bacteria is anionic, metal accumulation (calcite) on the surface of the wall is substantial, thus the entire cell becomes crystalline and they eventually plug the pores and cracks in concrete. This paper discusses the plugging of artificially cracked cement mortar using Bacillus Pasteurii and Sporosarcina bacteria combined with sand as a filling material in artificially made cuts in cement mortar which was cured in urea and CaCl2 medium. The effect on the compressive strength and stiffness of the cement mortar cubes due to the mixing of bacteria is also discussed in this paper. It was found that use of bacteria improves the stiffness and compressive strength of concrete. Scanning electron microscope (SEM) is used to document the role of bacteria in microbiologically induced mineral precipitation. Rod like impressions were found on the face of calcite crystals indicating the presence of bacteria in those places. Energy- dispersive X-ray (EDX) spectra of the microbial precipitation on the surface of the crack indicated the abundance of calcium and the precipitation was inferred to be calcite (CaCO3).

  16. Structural and functional studies of the early T lymphocyte activation 1 (Eta-1) gene. Definition of a novel T cell-dependent response associated with genetic resistance to bacterial infection

    PubMed Central

    1989-01-01

    We describe a murine cDNA, designated Early T lymphocyte activation 1 (ETA-1) which is abundantly expressed after activation of T cells. Eta- 1 encodes a highly acidic secreted product having structural features of proteins that bind to cellular adhesion receptors. The Eta-1 gene maps to a locus on murine chromosome 5 termed Ric that confers resistance to infection by Rickettsia tsutsugamushi (RT), an obligate intracellular bacterium that is the etiological agent for human scrub typhus. With one exception, inbred mouse strains that expressed the Eta- 1a allele were resistant to RT infection (RicR), and inbred strains expressing the Eta-1b allele were susceptible (RicS). These findings suggest that Eta-1 is the gene inferred from previous studies of the Ric locus (5). Genetic resistance to RT infection is associated with a strong Eta-1 response in vivo and inhibition of early bacterial replication. Eta-1 gene expression appears to be part of a surprisingly rapid T cell-dependent response to bacterial infection that may precede classical forms of T cell-dependent immunity. PMID:2787378

  17. Structural and functional studies of the early T lymphocyte activation 1 (Eta-1) gene. Definition of a novel T cell-dependent response associated with genetic resistance to bacterial infection.

    PubMed

    Patarca, R; Freeman, G J; Singh, R P; Wei, F Y; Durfee, T; Blattner, F; Regnier, D C; Kozak, C A; Mock, B A; Morse, H C

    1989-07-01

    We describe a murine cDNA, designated Early T lymphocyte activation 1 (ETA-1) which is abundantly expressed after activation of T cells. Eta-1 encodes a highly acidic secreted product having structural features of proteins that bind to cellular adhesion receptors. The Eta-1 gene maps to a locus on murine chromosome 5 termed Ric that confers resistance to infection by Rickettsia tsutsugamushi (RT), an obligate intracellular bacterium that is the etiological agent for human scrub typhus. With one exception, inbred mouse strains that expressed the Eta-1a allele were resistant to RT infection (RicR), and inbred strains expressing the Eta-1b allele were susceptible (RicS). These findings suggest that Eta-1 is the gene inferred from previous studies of the Ric locus (5). Genetic resistance to RT infection is associated with a strong Eta-1 response in vivo and inhibition of early bacterial replication. Eta-1 gene expression appears to be part of a surprisingly rapid T cell-dependent response to bacterial infection that may precede classical forms of T cell-dependent immunity. PMID:2787378

  18. Hydrophilic fluorescent nanogel thermometer for intracellular thermometry.

    PubMed

    Gota, Chie; Okabe, Kohki; Funatsu, Takashi; Harada, Yoshie; Uchiyama, Seiichi

    2009-03-01

    The first methodology to measure intracellular temperature is described. A highly hydrophilic fluorescent nanogel thermometer developed for this purpose stays in the cytoplasm and emits stronger fluorescence at a higher temperature. Thus, intracellular temperature variations associated with biological processes can be monitored by this novel thermometer with a temperature resolution of better than 0.5 degrees C. PMID:19199610

  19. Intracellular signalling during neutrophil recruitment

    PubMed Central

    Mócsai, Attila; Walzog, Barbara; Lowell, Clifford A.

    2015-01-01

    Recruitment of leucocytes such as neutrophils to the extravascular space is a critical step of the inflammation process and plays a major role in the development of various diseases including several cardiovascular diseases. Neutrophils themselves play a very active role in that process by sensing their environment and responding to the extracellular cues by adhesion and de-adhesion, cellular shape changes, chemotactic migration, and other effector functions of cell activation. Those responses are co-ordinated by a number of cell surface receptors and their complex intracellular signal transduction pathways. Here, we review neutrophil signal transduction processes critical for recruitment to the site of inflammation. The two key requirements for neutrophil recruitment are the establishment of appropriate chemoattractant gradients and the intrinsic ability of the cells to migrate along those gradients. We will first discuss signalling steps required for sensing extracellular chemoattractants such as chemokines and lipid mediators and the processes (e.g. PI3-kinase pathways) leading to the translation of extracellular chemoattractant gradients to polarized cellular responses. We will then discuss signal transduction by leucocyte adhesion receptors (e.g. tyrosine kinase pathways) which are critical for adhesion to, and migration through the vessel wall. Finally, additional neutrophil signalling pathways with an indirect effect on the neutrophil recruitment process, e.g. through modulation of the inflammatory environment, will be discussed. Mechanistic understanding of these pathways provide better understanding of the inflammation process and may point to novel therapeutic strategies for controlling excessive inflammation during infection or tissue damage. PMID:25998986

  20. Intracellular signalling during neutrophil recruitment.

    PubMed

    Mócsai, Attila; Walzog, Barbara; Lowell, Clifford A

    2015-08-01

    Recruitment of leucocytes such as neutrophils to the extravascular space is a critical step of the inflammation process and plays a major role in the development of various diseases including several cardiovascular diseases. Neutrophils themselves play a very active role in that process by sensing their environment and responding to the extracellular cues by adhesion and de-adhesion, cellular shape changes, chemotactic migration, and other effector functions of cell activation. Those responses are co-ordinated by a number of cell surface receptors and their complex intracellular signal transduction pathways. Here, we review neutrophil signal transduction processes critical for recruitment to the site of inflammation. The two key requirements for neutrophil recruitment are the establishment of appropriate chemoattractant gradients and the intrinsic ability of the cells to migrate along those gradients. We will first discuss signalling steps required for sensing extracellular chemoattractants such as chemokines and lipid mediators and the processes (e.g. PI3-kinase pathways) leading to the translation of extracellular chemoattractant gradients to polarized cellular responses. We will then discuss signal transduction by leucocyte adhesion receptors (e.g. tyrosine kinase pathways) which are critical for adhesion to, and migration through the vessel wall. Finally, additional neutrophil signalling pathways with an indirect effect on the neutrophil recruitment process, e.g. through modulation of the inflammatory environment, will be discussed. Mechanistic understanding of these pathways provide better understanding of the inflammation process and may point to novel therapeutic strategies for controlling excessive inflammation during infection or tissue damage. PMID:25998986

  1. Settling down: the genome of Serratia symbiotica from the aphid Cinara tujafilina zooms in on the process of accommodation to a cooperative intracellular life.

    PubMed

    Manzano-Marín, Alejandro; Latorre, Amparo

    2014-07-01

    Particularly interesting cases of mutualistic endosymbioses come from the establishment of co-obligate associations of more than one species of endosymbiotic bacteria. Throughout symbiotic accommodation from a free-living bacterium, passing through a facultative stage and ending as an obligate intracellular one, the symbiont experiences massive genomic losses and phenotypic adjustments. Here, we scrutinized the changes in the coevolution of Serratia symbiotica and Buchnera aphidicola endosymbionts in aphids, paying particular attention to the transformations undergone by S. symbiotica to become an obligate endosymbiont. Although it is already known that S. symbiotica is facultative in Acyrthosiphon pisum, in Cinara cedri it has established a co-obligate endosymbiotic consortium along with B. aphidicola to fulfill the aphid's nutritional requirements. The state of this association in C. tujafilina, an aphid belonging to the same subfamily (Lachninae) that C. cedri, remained unknown. Here, we report the genome of S. symbiotica strain SCt-VLC from the aphid C. tujafilina. While being phylogenetically and genomically very closely related to the facultative endosymbiont S. symbiotica from the aphid A. pisum, it shows a variety of metabolic, genetic, and architectural features, which point toward this endosymbiont being one step closer to an obligate intracellular one. We also describe in depth the process of genome rearrangements suffered by S. symbiotica and the role mobile elements play in gene inactivations. Finally, we postulate the supply to the host of the essential riboflavin (vitamin B2) as key to the establishment of S. symbiotica as a co-obligate endosymbiont in the aphids belonging to the subfamily Lachninane. PMID:24951564

  2. [A therapeutic Trojan horse: intracellular antibodies].

    PubMed

    Teillaud, J L

    1999-10-01

    Intracellular immunization is a novel therapeutic approach based on intracellular expression of recombinant antibody fragments, either Fab or single chain Fv (scFv generated by the assembly of the VH with the VL region), targeted to the desired cell compartment (cytosol, nucleus, endoplasmic reticulum ...) using appropriate targeting sequences. Due to their exquisite specificity, these intracellular antibodies can be used to neutralize or modulate the functional activity of the target molecule. Intracellular immunization strategies currently under investigation in the field of oncology are directed against mutated oncogenic molecules such as ErbB-2, p21ras, and p53, as well as against apoptosis-inhibiting molecules such as Bcl-2. The first Phase I clinical trials on intracellular immunization are under way in the United States. PMID:10573694

  3. 31 CFR 223.18 - Performance of agency obligations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Performance of agency obligations. 223.18 Section 223.18 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE SURETY COMPANIES DOING...

  4. 7 CFR 1450.105 - Obligations of participant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Obligations of participant. 1450.105 Section 1450.105 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP)...

  5. 7 CFR 1450.105 - Obligations of participant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Obligations of participant. 1450.105 Section 1450.105 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP)...

  6. 7 CFR 1450.105 - Obligations of participant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Obligations of participant. 1450.105 Section 1450.105 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP)...

  7. 7 CFR 1450.105 - Obligations of participant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Obligations of participant. 1450.105 Section 1450.105 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP)...

  8. Asset retirement obligations: a reporting concern for healthcare facilities.

    PubMed

    Berg, Gary G; Bayes, Paul E; Morgan, Robert G

    2008-11-01

    FASB statements and SEC guidelines give direction as to how healthcare organizations should account for their asset retirement obligations (AROs) where environmental issues are concerned. A key consideration is that current costs associated with environmental problems, such as encapsulating asbestos, are to be accounted for as part of an asset's cost and depreciated over the asset's remaining life. PMID:18990844

  9. 18 CFR 367.22 - Accounting for asset retirement obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Accounting for asset... GAS ACT General Instructions § 367.22 Accounting for asset retirement obligations. (a) An asset... tangible, long-lived asset that a service company is required to settle as a result of an existing...

  10. 6 CFR 25.5 - Obligations of seller.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-TERRORISM BY FOSTERING EFFECTIVE TECHNOLOGIES § 25.5 Obligations of seller. (a) Liability Insurance Required... Terrorism when Qualified Anti-Terrorism Technologies have been deployed in defense against, response to, or...-Terrorism Technology submit any information that would: (1) Assist in determining the amount of...

  11. 18 CFR 1314.6 - Obligations of TVA.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Obligations of TVA. 1314.6 Section 1314.6 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY BOOK-ENTRY... provided in § 1314.5(c), for the purposes of this part 1314, TVA and Reserve Banks shall treat...

  12. 18 CFR 1314.6 - Obligations of TVA.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Obligations of TVA. 1314.6 Section 1314.6 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY BOOK-ENTRY... provided in § 1314.5(c), for the purposes of this part 1314, TVA and Reserve Banks shall treat...

  13. 18 CFR 1314.6 - Obligations of TVA.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Obligations of TVA. 1314.6 Section 1314.6 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY BOOK-ENTRY... provided in § 1314.5(c), for the purposes of this part 1314, TVA and Reserve Banks shall treat...

  14. 18 CFR 1314.6 - Obligations of TVA.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Obligations of TVA. 1314.6 Section 1314.6 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY BOOK-ENTRY... provided in § 1314.5(c), for the purposes of this part 1314, TVA and Reserve Banks shall treat...

  15. 46 CFR 298.22 - Amortization of Obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the Documentation require you to make periodic payment of principal and interest on the Obligations. (b) Usually, the payment of principal (amortization) shall be made semi-annually, but in no event... of principal (level principal), unless we consent to the periodic payment of a constant...

  16. 11 CFR 9034.5 - Net outstanding campaign obligations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 11 Federal Elections 1 2012-01-01 2012-01-01 false Net outstanding campaign obligations. 9034.5 Section 9034.5 Federal Elections FEDERAL ELECTION COMMISSION PRESIDENTIAL ELECTION CAMPAIGN FUND... calendar days after the candidate's date of ineligibility, as determined under 11 CFR 9033.5, the...

  17. 11 CFR 9034.5 - Net outstanding campaign obligations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 11 Federal Elections 1 2014-01-01 2014-01-01 false Net outstanding campaign obligations. 9034.5 Section 9034.5 Federal Elections FEDERAL ELECTION COMMISSION PRESIDENTIAL ELECTION CAMPAIGN FUND... calendar days after the candidate's date of ineligibility, as determined under 11 CFR 9033.5, the...

  18. 11 CFR 9034.5 - Net outstanding campaign obligations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 11 Federal Elections 1 2013-01-01 2012-01-01 true Net outstanding campaign obligations. 9034.5 Section 9034.5 Federal Elections FEDERAL ELECTION COMMISSION PRESIDENTIAL ELECTION CAMPAIGN FUND... calendar days after the candidate's date of ineligibility, as determined under 11 CFR 9033.5, the...

  19. The Role Obligations of Students and Lecturers in Higher Education

    ERIC Educational Resources Information Center

    Regan, Julie-Anne

    2012-01-01

    The current discussion of consumerism in higher education focuses largely on what the providers are obliged to do for the consumers, against the background of rising tuition fees. This framework does not always sit comfortably with lecturers in the context of a learning and teaching relationship, as it appears to ignore the reciprocal obligations…

  20. 22 CFR 230.07 - Fiscal Agent obligations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Fiscal Agent obligations. 230.07 Section 230.07 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEES ISSUED UNDER THE EMERGENCY WARTIME SUPPLEMENTAL APPROPRIATIONS ACT OF 2003, PUB. L. 108-11-STANDARD TERMS AND CONDITIONS §...

  1. 22 CFR 230.07 - Fiscal Agent obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Fiscal Agent obligations. 230.07 Section 230.07 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEES ISSUED UNDER THE EMERGENCY WARTIME SUPPLEMENTAL APPROPRIATIONS ACT OF 2003, PUB. L. 108-11-STANDARD TERMS AND CONDITIONS §...

  2. 22 CFR 230.07 - Fiscal Agent obligations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Fiscal Agent obligations. 230.07 Section 230.07 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEES ISSUED UNDER THE EMERGENCY WARTIME SUPPLEMENTAL APPROPRIATIONS ACT OF 2003, PUB. L. 108-11-STANDARD TERMS AND CONDITIONS §...

  3. 22 CFR 230.07 - Fiscal Agent obligations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Fiscal Agent obligations. 230.07 Section 230.07 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEES ISSUED UNDER THE EMERGENCY WARTIME SUPPLEMENTAL APPROPRIATIONS ACT OF 2003, PUB. L. 108-11-STANDARD TERMS AND CONDITIONS §...

  4. 22 CFR 230.07 - Fiscal Agent obligations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Fiscal Agent obligations. 230.07 Section 230.07 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEES ISSUED UNDER THE EMERGENCY WARTIME SUPPLEMENTAL APPROPRIATIONS ACT OF 2003, PUB. L. 108-11-STANDARD TERMS AND CONDITIONS §...

  5. 29 CFR 1982.102 - Obligations and prohibited acts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false Obligations and prohibited acts. 1982.102 Section 1982.102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) PROCEDURES FOR THE HANDLING OF RETALIATION COMPLAINTS UNDER THE NATIONAL TRANSIT SYSTEMS SECURITY ACT OF 2007, ENACTED...

  6. 29 CFR 1982.102 - Obligations and prohibited acts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... IMPLEMENTING RECOMMENDATIONS OF THE 9/11 COMMISSION ACT OF 2007 Complaints, Investigations, Findings and... 29 Labor 9 2013-07-01 2013-07-01 false Obligations and prohibited acts. 1982.102 Section 1982.102... TRANSIT SYSTEMS SECURITY ACT OF 2007, ENACTED AS SECTION 1413 OF THE IMPLEMENTING RECOMMENDATIONS OF THE...

  7. 29 CFR 1982.102 - Obligations and prohibited acts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... IMPLEMENTING RECOMMENDATIONS OF THE 9/11 COMMISSION ACT OF 2007 Complaints, Investigations, Findings and... 29 Labor 9 2012-07-01 2012-07-01 false Obligations and prohibited acts. 1982.102 Section 1982.102... TRANSIT SYSTEMS SECURITY ACT OF 2007, ENACTED AS SECTION 1413 OF THE IMPLEMENTING RECOMMENDATIONS OF THE...

  8. 29 CFR 1982.102 - Obligations and prohibited acts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false Obligations and prohibited acts. 1982.102 Section 1982.102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) PROCEDURES FOR THE HANDLING OF RETALIATION COMPLAINTS UNDER THE NATIONAL TRANSIT SYSTEMS SECURITY ACT OF 2007, ENACTED...

  9. 5 CFR 2426.13 - Obligation to consult.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Obligation to consult. 2426.13 Section 2426.13 Administrative Personnel FEDERAL LABOR RELATIONS AUTHORITY, GENERAL COUNSEL OF THE FEDERAL LABOR RELATIONS AUTHORITY AND FEDERAL SERVICE IMPASSES PANEL FEDERAL LABOR RELATIONS AUTHORITY AND GENERAL COUNSEL OF THE FEDERAL LABOR...

  10. Medical Researchers' Ancillary Care Obligations: The Relationship-Based Approach.

    PubMed

    Olson, Nate W

    2016-06-01

    In this article, I provide a new account of the basis of medical researchers' ancillary care obligations. Ancillary care in medical research, or medical care that research participants need but that is not required for the validity or safety of a study or to redress research injuries, is a topic that has drawn increasing attention in research ethics over the last ten years. My view, the relationship-based approach, improves on the main existing theory, Richardson and Belsky's 'partial-entrustment model', by avoiding its problematic restriction on the scope of health needs for which researchers could be obligated to provide ancillary care. Instead, it grounds ancillary care obligations in a wide range of morally relevant features of the researcher-participant relationship, including the level of engagement between researchers and participants, and weighs these factors against each other. I argue that the level of engagement, that is, the duration and intensity of interactions, between researchers and participants matters for ancillary care because of its connection to the meaningfulness of a relationship, and I suggest that other morally relevant features can be grounded in researchers' role obligations. PMID:26424512

  11. 48 CFR 333.213 - Obligation to continue performance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Obligation to continue performance. 333.213 Section 333.213 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES GENERAL... performance. (a) The Contracting Officer shall use the Disputes clause at FAR 52.233-1 without the use...

  12. 18 CFR 367.2300 - Account 230, Asset retirement obligations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Account 230, Asset retirement obligations. 367.2300 Section 367.2300 Conservation of Power and Water Resources FEDERAL ENERGY... GAS ACT Balance Sheet Chart of Accounts Other Noncurrent Liabilities § 367.2300 Account 230,...

  13. Family Obligations in Micronesian Cultures: Implications for Educators

    ERIC Educational Resources Information Center

    Ratliffe, Katherine T.

    2010-01-01

    Micronesian people, a new group of immigrants to the USA, have a strong system of responsibilities to family members that guides their priorities and actions. When family obligations clash with school priorities, conflicts can occur. I interviewed 26 adults to learn about the relationships and responsibilities of family members to each other in…

  14. 24 CFR 982.551 - Obligations of participant.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Obligations of participant. 982.551 Section 982.551 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT SECTION 8 TENANT...

  15. 29 CFR 1979.102 - Obligations and prohibited acts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Obligations and prohibited acts. 1979.102 Section 1979.102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... THE WENDELL H. FORD AVIATION INVESTMENT AND REFORM ACT FOR THE 21ST CENTURY Complaints,...

  16. 7 CFR 1000.28 - Termination of obligations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (7 CFR 900.50 through 900.71) within the applicable 2-year period indicated below, the obligation of... Agreements and Orders; Milk), DEPARTMENT OF AGRICULTURE GENERAL PROVISIONS OF FEDERAL MILK MARKETING ORDERS... run until the first day of the month following the month during which all such records pertaining...

  17. 48 CFR 252.232-7007 - Limitation of Government's obligation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... accordingly. (e) If, solely by reason of failure of the Government to allot additional funds, by the dates... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Limitation of Government's... of Provisions And Clauses 252.232-7007 Limitation of Government's obligation. As prescribed in...

  18. 48 CFR 252.232-7007 - Limitation of Government's obligation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... accordingly. (e) If, solely by reason of failure of the Government to allot additional funds, by the dates... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Limitation of Government's... of Provisions And Clauses 252.232-7007 Limitation of Government's obligation. As prescribed in...

  19. 14 CFR 1300.22 - Termination of obligations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Termination of obligations. 1300.22 Section 1300.22 Aeronautics and Space AIR TRANSPORTATION SYSTEM STABILIZATION OFFICE OF MANAGEMENT AND BUDGET AVIATION DISASTER RELIEF-AIR CARRIER GUARANTEE LOAN PROGRAM Minimum Requirements and Application Procedures § 1300.22 Termination of...

  20. 28 CFR 811.3 - Notice of obligation to register.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... COLUMBIA SEX OFFENDER REGISTRATION § 811.3 Notice of obligation to register. (a) Sex offenders may be... Sex Offender Registration Act of 1999 (D.C. Official Code sections 22-4003, 4005, 4007) (relating to notice by the District of Columbia Superior Court, Department of Corrections, or CSOSA); 18 U.S.C....