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Results 451 - 500 of 1936
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Alonso-Hearn Marta - - 2008
Mycobacterium avium subsp. paratuberculosis infection of cattle takes place through the intestinal mucosa. To identify M. avium subsp. paratuberculosis genes associated with the invasion of bovine epithelial cells in vitro, we screened a library of transposon mutants. Several mutants of M. avium subsp. paratuberculosis were identified which invaded Madin-Darby bovine ...
aalster and tzohary
The colonies of brown colored small sphaerical cells are colones of Microcystis botris, a less common species of this genus in Lake Kinneret. The black dots in each individual cell are gas vesicles, typical of this genus, giving it positive buoyancy. The 3 colorless organims accociated with the Microcystis colonies ...
Rajam Gowrisankar - - 2008
Pneumococcal surface adhesin A (PsaA) is a putative pneumococcal (Pnc) adhesin known to bind to nasopharyngeal (NP) epithelial cells. This study evaluated the effect of peptides within a functional domain of PsaA on NP cells. Detroit 562 NP cells were treated with synthetic peptides derived from PsaA (P4, P6, and ...
Parent Mary E - - 2008
Quorum sensing is almost always regarded as a population density effect in three-dimensional bulk samples of bacteria. Here we create two-dimensional samples of Vibrio fischeri cells adhered onto glass surfaces to examine the effect of local population densities on quorum sensing. This is done by measuring the luminescent response. The ...
Martin Nathaniel I - - 2007
Lipid II is an essential cell-wall precursor required for the growth and replication of both Gram-positive and Gram-negative bacteria. Compounds that use lipid II to selectively target bacterial cells for destruction represent an important class of antibiotics. Clinically, vancomycin is the most important example of an antibiotic that operates in ...
Sarkar Madhubanti - - 2007
Anaplasma phagocytophilum, the causative agent of human granulocytic anaplasmosis, is an obligate intracellular bacterium that infects neutrophils and neutrophil precursors. Bacterial recognition of P-selectin glycoprotein ligand-1 (PSGL-1) and the alpha2,3-sialylated- and alpha1,3-fucosylated-moiety sialyl-Lewis x (sLe(x)), which modifies the PSGL-1 N terminus, is important for adhesion to and invasion of myeloid ...
Kafsack Björn F C BF Department of Microbiology and Immunology, University of Michigan Medical School, 5641 Medical Sciences Bldg. II, 1150 West Medical Center Dr., Ann Arbor, MI 48109-0620, - - 2007
The phylum Apicomplexa includes parasites responsible for global scourges such as malaria, cryptosporidiosis, and toxoplasmosis. Parasites in this phylum reproduce inside the cells of their hosts, making invasion of host cells an essential step of their life cycle. Characterizing the stages of host-cell invasion, has traditionally involved tedious microscopic observations ...
Alto Neal Mathew - - 2007
Intestinal epithelial cells serve as the major defense barrier against enteric bacterial infection. However, pathogens have devised remarkable schemes to usurp this formidable immune barrier. In a study recently published in Cell, Iwai et al. expand our understanding of how Shigella colonizes the epithelium by describing bacterial IpaB as a ...
Morgan-Sagastume Fernando - - 2008
Bacterial biomass was characterised in supernatants from activated sludge from a nutrient removal plant after settling before and after applying gentle shear (G approximately 600 s(-1)). Free-swimming and floc-associated bacteria were quantified by microscopy and their identity was determined by fluorescence in-situ hybridization (FISH). Total cell numbers in the supernatant ...
Kamgang J O - - 2007
AIMS: To determine the efficiency of an electric discharge of the gliding arc type for the destruction of Staphylococcus epidermidis planktonic, adherent and biofilm cells. METHODS AND RESULTS: Bacterial cells were treated in humid air and at atmospheric pressure by a nonthermal quenched plasma of the glidarc type. The kinetics ...
Zarfl Christiane - - 2008
The uptake of sulfonamides into bacterial cells was simulated by a dynamic model to estimate bioavailability and steady-state accumulation of sulfonamides in the cells. Uptake of sulfonamides is modeled as diffusion-like transport of the neutral molecule and the ionic species. Speciation outside and inside the cell depends on the extra- ...
Feng Youzhi - - 2007
Biosorption has been shown to be an eco-friendly approach to remove heavy metal ions. In this study, the photosynthetic bacteria Rhodobacter capsulatus was screened and found to have strong ability to adsorb Au(III). The maximum specific uptake of living cells was over 92.43 mg HAuCl(4)/g dry weight of cell in ...
Bakowski Malina A - - 2007
The intracellular bacterial pathogen, Salmonella enterica serovar Typhimurium (S. typhimurium), causes disease in a variety of hosts. To invade and replicate in host cells, these bacteria subvert host molecular machinery using bacterial proteins, called effectors, which they translocate into host cells using specialized protein delivery systems. One of these effectors, ...
Verastegui Manuela - - 2007
The specific mechanisms underlying Taenia solium oncosphere adherence and penetration in the host have not been studied previously. We developed an in vitro adhesion model assay to evaluate the mechanisms of T. solium oncosphere adherence to the host cells. The following substrates were used: porcine intestinal mucosal scrapings (PIMS), porcine ...
Chen Guokai G Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, - - 2007
Social amoebae feed on bacteria in the soil but aggregate when starved to form a migrating slug. We describe a previously unknown cell type in the social amoeba, which appears to provide detoxification and immune-like functions and which we term sentinel (S) cells. S cells were observed to engulf bacteria ...
Shi Lei - - 2007
BACKGROUND: Viability measurements of individual bacteria are applied in various scopes of research and industry using approaches where propidium iodide (PI) serves as dead cell indicator. The reliability of PI uptake as a cell viability indicator for dead (PI permeable) and viable (PI impermeable) bacteria was tested using two soil ...
Rapala-Kozik Maria - - 2008
The invasion of human host by pathogenic microorganisms is often associated with increased kinin production which may occur due to the action of pathogen secretory proteinases or the activation of host's surface-dependent kinin generation cascade, initiated by the adsorption of high molecular weight kininogen (HK) on the pathogen cells. In ...
Sahu Saura C - - 2007
Internalin A is a surface protein of the facultative intracellular pathogen Listeria monocytogenes that interacts with the human host cell protein E-cadherin to facilitate invasion of epithelial cells. A single amino acid substitution at position 16 in mouse E-cadherin prevents this interaction. Synthetic polypeptides of 30 aa encompassing position 16 ...
Caracuel-Rios Zaira Z School of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United - - 2007
This review describes current advances in understanding the biology of plant infection by the rice blast fungus Magnaporthe grisea. Development of the specialized infection structure, the appressorium, in M. grisea has recently been shown to be controlled by cell cycle progression and initiation of autophagic, programmed cell death in the ...
Bell-Sakyi Lesley - - 2007
Over 40 cell lines are currently available from 13 ixodid and one argasid tick species. The successful isolation and propagation of several economically important tick-borne pathogens in tick cell lines has created a useful model to study interactions between tick cells and these viral and bacterial disease agents. Tick cell ...
Schneider Ilka - - 2007
Intracellular leucoproliferative Theileria are unique as eukaryotic organisms that transform the immune cells of their ruminant host. Theileria utilize the uncontrolled proliferation for rapid multiplication and distribution into host daughter cells. The equal distribution of the schizont into the daughter cells is thought to be accomplished by a tight association ...
Frýdlová Ivana - - 2007
The ability to invade a solid substrate is an important phenomenon due to its connection with pathogenic activity of fungi. We report here on invasion displayed by MATalpha cells of Saccharomyces cerevisiae lacking Isw2p, a subunit of the ISW2 chromatin remodelling complex. We found that on minimal medium, where the ...
Fortune Sarah M - - 2007
Mycobacteria are uniquely adapted to grow inside host macrophages. As Clay et al. show in this issue of Cell Host & Microbe and as van der Wel et al. show in a recent issue of Cell, there are both benefits and drawbacks for the pathogen in adopting this strategy, and ...
Norris Vic - - 2007
Five common assumptions about the first cells are challenged by the pre-biotic ecology model and are replaced by the following propositions: firstly, early cells were more complex, more varied and had a greater diversity of constituents than modern cells; secondly, the complexity of a cell is not related to the ...
Bozue Joel - - 2007
Bacillus anthracis is the causative agent of anthrax, and the spore form of the bacterium represents the infectious particle introduced into a host. The spore is surrounded by an exosporium, a loose-fitting membrane composed of proteins and carbohydrates from which hair-like projections extend. These projections are composed mainly of BclA ...
Teughels W - - 2007
It is known that beneficial bacteria can suppress the emergence of pathogenic bacteria, particularly in the gastrointestinal tract. This study examined the potential for a similar suppression of Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans colonization of epithelial cells, due to its potential relevance in periodontal diseases. Seven presumed beneficial bacteria were examined ...
Ammendolia M G - - 2007
Among Listeria genus, only two species, Listeria ivanovii and Listeria monocytogenes, are pathogenic. L. ivanovii is almost only associated with infections in animals, mainly sheep and cattle, and has rarely been associated with human infections, whereas L. monocytogenes causes severe illnesses in both humans and animals. To further investigate the ...
Eichmann Ruth - - 2008
Parasitic powdery mildew fungi have to overcome basic resistance and manipulate host cells to establish a haustorium as a functional feeding organ in a host epidermal cell. Currently, it is of central interest how plant factors negatively regulate basal defense or whether they even support fungal development in compatible interactions. ...
Ly Kim Thien - - 2007
Salmonella enterica is an enteric bacterial pathogen that causes a variety of food and water-borne diseases ranging from gastroenteritis to typhoid fever. Ingested bacteria colonize the intestinal epithelium by triggering their own phagocytosis, using a sophisticated array of effector proteins that are injected into the host cell cytoplasm through a ...
Fujiya Mikihiro - - 2007
Bacteria use quorum-sensing molecules (QSMs) to communicate within as well as across species. However, the effects of QSMs on eukaryotic host cells have received limited attention. We report that the quorum-sensing pentapeptide, competence and sporulation factor (CSF), of the Gram-positive bacterium Bacillus subtilis activates key survival pathways, including p38 MAP ...
Vannini Lucia - - 2007
A new family of putative signaling molecules having a 2(5H)-furanone configuration has been described in this work. They were released during late exponential or stationary phase in different growth media by some gram-positive bacteria, such as Lactobacillus helveticus, Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus sanfranciscensis, Enterococcus faecalis, and a gram-negative species, ...
Fruth Ingrid A IA Department of Microbiology, Molecular Biology and Biochemistry, University of Idaho, Life Sciences South Room 142, Moscow, ID 83843, - - 2007
The obligate intracellular parasite Toxoplasma gondii is an important pathogen of humans and animals. Some of the devastating consequences of toxoplasmosis are in part due to the lysis of the host cell during parasite egress. The process of egress is poorly understood and since it is asynchronous in tissue culture ...
Jassim S A A - - 2007
AIMS: To develop a method for rapid detection of bacteria via bacteriophage amplification coupled with exogenous fluorochromic stains. METHODS AND RESULTS: A method for the rapid detection of bacteria was developed which consisted of exposing the sample suspected to contain target cells to host-specific phage. After at least one infection ...
Colombo A V - - 2007
BACKGROUND AND OBJECTIVE: Interactions between oral bacteria and gingival epithelial cells play an important role in the pathogenesis of periodontal diseases. This study used in situ hybridization with 16 rRNA probes and confocal microscopy to detect the periodontal pathogens Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Tannerella forsythia, and Treponema denticola within epithelial ...
Purdy Georgiana E - - 2007
A Shigella flexneri degP mutant, which was defective for plaque formation in Henle cell monolayers, had a reduced amount of IcsA detectable on the bacterial surface with antibody. However, the mutant secreted IcsA to the outer membrane at wild-type levels. This suggests that IcsA adopts an altered conformation in the ...
Bachmann Herwig - - 2007
The luminescence signal of luxAB-encoded bacterial luciferase strongly depends on the metabolic state of the host cell, which restricts the use of this reporter system to metabolically active bacteria. Here we show that in stationary-phase cells of Lactococcus lactis, detection of luciferase is significantly improved by the addition of riboflavin ...
Hudson Debra L - - 2007
Type III secretion systems (T3SS) are conserved in many pathogenic gram-negative bacteria. Small molecules that specifically target T3SS in Yersinia and Chlamydia spp. have recently been identified. Here we show that two such compounds inhibit Salmonella T3SS-1, preventing secretion of T3SS-1 effectors, invasion of cultured epithelial cells, and enteritis in ...
Harrison Joe J - - 2007
Many Candida spp. produce surface-adherent biofilm populations that are resistant to antifungal compounds and other environmental stresses. Recently, certain chelating agents have been recognized as having strong antimicrobial activity against biofilms of Candida species. This study investigated and characterized the concentration- and time-dependent killing of Candida biofilms by the chelators ...
Joseph Biju - - 2007
In the past decades impressive knowledge has been accumulated concerning the basic mechanisms of interactions between intracellular bacteria and their host cells. Comparatively little is known on the metabolic requirements necessary for efficient replication of these bacteria within their specific host cell compartments. Recent developments in functional genomics have led ...
Seveau Stéphanie - - 2007
The facultative intracellular bacterial pathogen Listeria monocytogenes has evolved multiple strategies to invade a large panel of mammalian cells. Host cell invasion is critical for several stages of listeriosis pathology such as the initial crossing of the host intestinal barrier and the successive colonization of diverse target organs including the ...
Cossart Pascale - - 2007
Listeria monocytogenes is an ubiquitous gram positive bacterium responsible for a severe food borne disease in human and animals which has become a multifaceted model. Indeed, it is a facultative intracellular bacterium that induces an amazingly rapid and sterilizing T-cell response and has been--and still is--widely used by immunologists. Listeria's ...
Astrauskiene D - - 2007
Persistence of arthritis-triggering bacteria can cause chronization of reactive arthritis (ReA). In the evaluation of bacterial persistence in ReA, the persistence of both the triggering bacteria and also of the other bacteria residing in the foci of chronic infection, are important. Two forms of bacterial persistence, cell wall-deficient bacteria (L-forms) ...
Russell Brooke H BH Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, - - 2007
The current model for Bacillus anthracis dissemination in vivo focuses on macrophages as carriers. However, recent evidence suggested that other host cells may also play a role in the process. Here, we tested the possibility of B. anthracis being internalized by a human fibroblast cell line, HT1080 and an epithelial ...
Zilm Peter S - - 2007
Fusobacterium nucleatum is a Gram-negative anaerobic organism considered to play an important role in the progression of periodontal disease and is commonly found in clinical infections of other body sites. Apart from its metabolic versatility, its cell-surface properties enable it to attach to epithelial cells, collagen, gingival epithelial cells and ...
Rice Kelly C - - 2007
The Staphylococcus aureus cidA and lrgA genes have been shown to affect cell lysis under a variety of conditions during planktonic growth. It is hypothesized that these genes encode holins and antiholins, respectively, and may serve as molecular control elements of bacterial cell lysis. To examine the biological role of ...
Liu Yunying - - 2007
Interactions of virulent Leptospira interrogans with murine monocyte-macrophage-like J774A.1 cells and Vero (African green monkey kidney fibroblasts) cells from attachment to internalization were investigated by a series of morphological analysis. Fontana silver staining revealed that only the pathogenic leptospires were able to attach to host cells and the attachment pattern ...
Sotirova A - - 2009
The effect of rhamnolipid-biosurfactant produced by Pseudomonas sp. PS-17 on cell surface structures of Pseudomonas aeruginosa NBIMCC 1390 was studied. The results demonstrated that the rhamnolipid at concentrations below and above CMC provoked a multi-component response of the bacterial cells without affecting their growth and viability. Above CMC, the rhamnolipid ...
Wagner Jennifer K - - 2007
Understanding the mechanisms underlying the establishment of different bacterial cell shapes and the advantage that a particular shape imparts is one of the most fascinating and challenging areas of study in microbiology. One remarkable example of bacterial morphogenesis is the elaboration of long, tubular extensions of the cell envelope of ...
Sperandio Vanessa V University of Texas Southwestern Medical Center, Dept of Microbiology, 5325 Harry Hines Blvd, Dallas, TX 75390-9048, USA. - - 2007
The growing challenge of antimicrobial resistance and the paucity of novel antibiotics underscore the importance of developing novel therapeutics. Bacterial cell-to-cell signaling constitutes a novel drug target. Quorum sensing (QS) is a cell-to-cell signaling mechanism that refers to the ability of bacteria to respond to chemical hormone-like molecules called autoinducers. ...
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