Search results for "Bacterial Adhesion"
showing 10 items of 48 documents
Purification and characterization of a Salmonella typhimurium agglutinin from gut mucus secretions.
1992
One of the earliest events in Salmonella typhimurium pathogenesis seems to be the interaction of the bacterium with the mucus of the gut. After exposing S. typhimurium to guinea-pig colon, we were able to demonstrate by electron microscopy that S. typhimurium bacteria were trapped on, or in, the mucus layer. Specific components isolated from crude mucus secretions were found to aggregate the bacteria. The degree of bacterial aggregation was dependent on the protein concentration of the crude mucus and on time. Aggregation of S. typhimurium could be abolished by sugars: L-fucose exhibited the strongest inhibition, followed by D-glucose, D-galactose and D-mannose. Lectins were also capable of…
Submicrometer-Sized Roughness Suppresses Bacteria Adhesion.
2020
Biofilm formation is most commonly combatted with antibiotics or biocides. However, proven toxicity and increasing resistance of bacteria increase the need for alternative strategies to prevent adhesion of bacteria to surfaces. Chemical modification of the surfaces by tethering of functional polymer brushes or films provides a route toward antifouling coatings. Furthermore, nanorough or superhydrophobic surfaces can delay biofilm formation. Here we show that submicrometer-sized roughness can outweigh surface chemistry by testing the adhesion of E. coli to surfaces of different topography and wettability over long exposure times (>7 days). Gram-negative and positive bacterial strains are tes…
Anti-adhesion agents against Gram-positive pathogens
2014
The rise of antibiotic-resistance as well as the deficiency of investments by pharmaceutical companies in the development of new antibiotics, have stimulated the investigation of alternative strategies to conventional antibiotics for counteracting the pathogens. A fundamental step of Gram positive pathogenesis is the bacterial adhesion to the host tissue involving a direct and a specific interaction between bacterial surface molecules and host ligands. Targeting the adhesion is a good strategy to design novel anti-infective drugs agents useful to interfere with the pathogenic process and with a virulence mechanism as biofilm formation. This review is focused on anti-virulence compounds whic…
Biofilm development by potentially pathogenic non-pigmented rapidly growing mycobacteria
2008
Abstract Background A study to evaluate the biofilm-development ability in three different media (Middlebrook 7H9, sterile tap water and PBS-5% glucose) was performed with 19 collection strains from 15 different species on non-pigmented rapidly growing mycobacteria (NPRGM). A microtiter plate assay was developed to evaluate the percentage of covered surface of the microtiter plate wells in different days from day 1 to day 69. Results All strains were able to develop biofilm in all the tested media. Middlebrook 7H9 showed the fastest growth, followed by sterile tap water and PBS-5% glucose. A sigmoid growth curve was detected in all the strains both in Middlebrook 7H9 and in sterile tap wate…
The hemagglutinin of Staphylococcus saprophyticus binds to a protein receptor on sheep erythrocytes.
1997
Staphylococcus saprophyticus, an important cause of urinary tract infections, produces two major surface proteins, the S. saprophyticus surface-associated protein (Ssp) and the hemagglutinin, which mediates fibronectin binding and also functions as the major adhesion of the organism. The hemagglutinating and fibronectin binding functions probably reside on different parts of the molecule. To identify a receptor on eukaryotic cells, binding and inhibition studies with acidic and neutral glycosphingolipids, carbohydrates, and proteins of sheep erythrocyte membranes were conducted. S. saprophyticus did not bind to any glycosphingolipid and no inhibition was observed when hemagglutination assay…
Comparing the different morphotypes of a fish pathogen - implications for key virulence factors in Flavobacterium columnare
2014
Background: Flavobacterium columnare (Bacteroidetes) is the causative agent of columnaris disease in farmed freshwater fish around the world. The bacterium forms three colony morphotypes (Rhizoid, Rough and Soft), but the differences of the morphotypes are poorly known. We studied the virulence of the morphotypes produced by F. columnare strain B067 in rainbow trout ( Onconrhynchus mykiss ) and used high-resolution scanning electron microscopy to identify the fine structures of the cells grown in liquid and on agar. We also analysed the proteins secreted extracellularly and in membrane vesicles to identify possible virulence factors. Results: Only the Rhizoid morphotype was virulent in rain…
Interactions in dual species biofilms between Listeria monocytogenes EGD-e and several strains of Staphylococcus aureus.
2008
International audience; Six environmental isolates of Staphylococcus aureus and one collection strain were investigated for their ability to form monospecies biofilms and dual species biofilms with Listeria monocytogenes EGD-e on stainless steel coupons. All isolates were able to grow as biofilms but their ability to form monospecies biofilms differed. The population of L. monocytogenes EGD-e in dual species biofilms was not affected by the presence of S. aureus isolates except for strain CIP 53.156. The effect of L. monocytogenes EGD-e on the population of S. aureus was strain dependent: S. aureus population either increased or decreased or was not affected in the presence of L. monocytoge…
Sortase A Inhibitors: Recent Advances and Future Perspectives
2015
Here, we describe the most promising small synthetic organic compounds that act as potent Sortase A inhibitors and cater the potential to be developed as antivirulence drugs. Sortase A is a polypeptide of 206 amino acids, which catalyzes two sequential reactions: (i) thioesterification and (ii) transpeptidation. Sortase A is involved in the process of bacterial adhesion by anchoring LPXTG-containing proteins to lipid II. Sortase A inhibitors do not affect bacterial growth, but they restrain the virulence of pathogenic bacterial strains, thereby preventing infections caused by Staphylococcus aureus or other Gram-positive bacteria. The efficacy of the most promising inhibitors needs to be com…
Nanostructured medical sutures with antibacterial properties
2014
Bacterial repellence in suture materials is a desirable property that can potentially improve the healing process by preventing infection. We describe a method for generating nanostructures at the surface of commercial sutures of different composition, and their potential for preventing biofilm formation. We show how bacteria attachment is altered in the presence of nanosized topographies and identify optimum designs for preventing it without compromising biocompatibility and applicability in terms of nanostructure robustness or tissue friction. These studies open new possibilities for flexible and cost-effective realization of topography-based antibacterial coatings for absorbable biomedic…
The impact of growth history and flagellation on the adhesion of variousListeria monocytogenesstrains to polystyrene
2009
International audience; The contribution of growth history and flagella to adhesion of Listeria monocytogenes was analysed. An in-frame deletion on the flagellin encoding gene (flaA) was performed in L. monocytogenes EGD-e to compare its adhesion ability with the parental strain, after cultivation at various pH values and temperatures. The pH, as well as the temperature, affected the adhesion of L. monocytogenes EGD-e. In addition, the adhesion of L. monocytogenes EGD-e was reduced in energy-depressed cells. Conversely, the physicochemical bacterial surface characteristics affected by growth history did not influence the adhesion. Adhesion variations observed among environmental and clinica…