Search results for "Bacterial Adhesion"
showing 10 items of 48 documents
Formation and Characterization of Early Bacterial Biofilms on Different Wood Typologies Applied in Dairy Production
2018
ABSTRACT The main hypothesis of this work was that Sicilian forestry resources are suitable for the production of equipment to be used in cheese making and indigenous milk lactic acid bacteria (LAB) are able to develop stable biofilms providing starter and nonstarter cultures necessary for curd fermentation and cheese ripening, respectively. Hence, the present work was carried out with deproteinized whey to evaluate LAB biofilm formation on different woods derived from tree species grown in Sicily. Microbiological and scanning electron microscopy analyses showed minimal differences in microbial levels and compositions for the neoformed biofilms. The specific investigation of Salmonella spp.…
Dextran production by Lactobacillus sakei MN1 coincides with reduced autoagglutination, biofilm formation and epithelial cell adhesion
2017
40 p.-7 fig.-4 fig.supl.
A new class of phenylhydrazinylidene derivatives as inhibitors of Staphylococcus aureus biofilm formation
2016
In the struggle against the emergence of the antibiotic resistance, new molecules targeting biofilm formation could be useful as adjuvant of conventional antibiotics. This study focused on a new class of 2-phenylhydrazinylidene derivatives as antivirulence agents. The compound 12e showed interesting activities against biofilm formation of all tested Staphylococcus aureus strains with IC50 ranging from 1.7 to 43 µM; compounds 12f and 13a resulted strong inhibitors of S. aureus ATCC 6538 and ATCC 29213 biofilm formation with IC50 of 0.9 and 0.8 µM, respectively. A preliminary study on the mechanism of action was carried on evaluating the inhibition of sortase A transpeptidase. Compound 12e re…
A 66-kilodalton heat shock protein of Salmonella typhimurium is responsible for binding of the bacterium to intestinal mucus
1992
Salmonella typhimurium infections have increased during the last few years. However, the interplay of virulence factors in S. typhimurium pathogenesis is still poorly understood, particularly with regard to the mechanisms and components of the bacterium which are involved in its interaction with the intestinal mucus. We have observed that S. typhimurium is aggregated by incubation with colonic mucus (guinea pig model). To quantify this phenomenon, an aggregation assay was established. By using this assay, it was found that the aggregation profile of S. typhimurium strains freshly isolated from patients (age 9 and older) with salmonellosis correlated with the severity of the disease. An isol…
The Interaction of Buccal Mucosal Epithelial Cells with E. coli Bacteria Enhances the Intraepithelial Calcium Flux and the Release of Prostaglandin E…
1999
Mucosal epithelial cells contribute significantly to host defense mechanisms. Uroepithelial cells (UEC) from healthy donors suppress bacterial growth in vitro. Bacterial adherence to UEC has been shown to be a prerequisite. Similar results have been shown for buccal epithelial cells (BEC). The host response triggered by the host-parasite interaction seems to involve signal transduction and intracellular activation of second messengers. In this study the intraepithelial calcium flux was analyzed in individual BEC after bacterial contact. BEC were derived from scrapes of the buccal mucosa and labelled with fluo-3 (a calcium indicator). Thereafter the cells were analyzed immediately with a FAC…
Gangliosides and sialic acid effects upon newborn pathogenic bacteria adhesion: An in vitro study
2012
The effect of the main gangliosides (GM(1), GM(3), GD(3)) and free sialic acid (Neu5Ac) upon the adhesion of pathogenic bacteria implicated in infant diarrhoea is assessed in vitro using the Caco-2 cell line. Concentrations of the bioactive compounds found in the bioaccessible (soluble) fraction of infant formula and human milk are employed. Bacterial adhesion behaviour included enterotoxigenic Escherichia coli (ETEC), enteropathogenic E.coli (EPEC), Listeria monocytogenes, Salmonella entericaserovartyphi, Shigella sonnei, Campylobacter jejuni and Helicobacter pylori. Three different approaches were assayed: pre-incubation of bacteria and compounds before addition to cells (competition); pr…
Tailoring Novel PTFE Surface Properties: Promoting Cell Adhesion and Antifouling Properties via a Wet Chemical Approach
2016
Many biomaterials used for tissue engineering applications lack cell-adhesiveness and, in addition, are prone to nonspecific adsorption of proteins. This is especially important for blood-contacting devices such as vascular grafts and valves where appropriate surface properties should inhibit the initial attachment of platelets and promote endothelial cell colonization. As a consequence, the long-term outcome of the implants would be improved and the need for anticoagulation therapy could be reduced or even abolished. Polytetrafluoroethylene (PTFE), a frequently used polymer for various medical applications, was wet-chemically activated and subsequently modified by grafting the endothelial …
Influence of surface porosity and pH on bacterial adherence to hydroxyapatite and biphasic calcium phosphate bioceramics
2008
Hydroxyapatite (HA) and biphasic calcium phosphate (BCP) ceramic materials are widely employed as bone substitutes due to their porous and osteoconductive structure. Their porosity and the lowering of surrounding pH as a result of surgical trauma may, however, predispose these materials to bacterial infections. For this reason, the influence of porosity and pH on the adherence of common Gram-positive bacteria to the surfaces of these materials requires investigation. Mercury intrusion porosimetry measurements revealed that the pore size distribution of both bioceramics had, on a logarithmic scale, a sinusoidal frequency distribution ranging from 50 to 300 nm, with a mean pore diameter of 20…
In vitro efficacy of a Hydrophilic Central Venous Catheter Loaded with Silver to Prevent Microbial Colonization
1998
A method was developed to load the surface of a central venous catheter with silver to prevent bacterial colonization. Silver confers a broad antimicrobial activity with a relatively low risk of resistance. Catheters were incubated with a silver nitrate solution in different concentrations. The solvent, incubation temperature and incubation period were varied to examine the influence on the catheter loading. With increasing incubation temperature, time and concentration of silver nitrate, higher rates of silver elution were observed by atomic absorption spectroscopy. Furthermore, by using ethanol-water as a solvent instead of pure water, the amount of silver bound to the catheter surface wa…
The long-term cytoskeletal rearrangement induced by rabbit enteropathogenic Escherichia coli is Esp dependent but intimin independent.
1999
Attaching and effacing rabbit enteropathogenic Escherichia coli (REPEC) of the O103 serogroup adhere diffusely on HeLa cells and trigger a slow progressive cytopathic effect (CPE) characterized by the recruitment of vinculin and the assembly of actin stress fibres. In contrast to REPEC O103, the reference human EPEC strain E2348/69 is unable to trigger the CPE. In this study, we have shown first that the fimbrial adhesin AF/R2, which mediates the diffuse adhesion of REPEC O103, was not sufficient to induce the CPE capability upon E2348/69. Non-polar mutants of REPEC O103 for espA, espB, espD and eae were then constructed. The four mutants were unable to induce attaching and effacing lesions…