Interaction of Staphylococcus epidermidis with endothelial cells in vitro

Abstract

Staphylococcus epidermidis is a leading cause of nosocomial bacteremia, yet virtually nothing is known about how this pathogen interacts with human endothelial cells. We present evidence here that two biofilm-producing strains of S. epidermidis adhere to two types of endothelial cell lines in vitro and that adherence is significantly increased after briefly heat-treating the bacteria at 40 degrees C in the presence of calcium. This mild heat treatment resulted in bacteria that were 5 to more than 20 times more adherent than untreated controls. While the adherence of bacteria in all phases of growth was increased after heat treatment, heat-treated late stationary phase cells were generally the most adherent. Electron microscopy demonstrated that S. epidermidis was internalized and appeared to exist free in the cytoplasm. Adherence to endothelium, should it occur in vivo during bacteremia, may be a virulence factor associated with this bacterium's pathogenesis.

The role of polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis adhesion to host tissues and subsequent antibiotic tolerance

“…However, the percentage of bacterial cells that adhered to host cells in relation to the initial inoculum was very small for both S. epidermidis strains, as demonstrated by the percentage of initial inoculum adhered (3.5% and 14.7% for the 1457 strain, and 1.9% and 5.4% for the 1457-M10 strain). This is in accordance with previous studies, which indicate a lower S. epidermidis propensity to adhere to urinary tissue [37,38] and to endothelial cells [39].…”

Cellular Pharmacodynamics of the Novel Biaryloxazolidinone Radezolid: Studies with Infected Phagocytic and Nonphagocytic cells, UsingStaphylococcus aureus,Staphylococcus epidermidis,Listeria monocytogenes, andLegionella pneumophila

“…We selected different types of bacteria with distinct subcellular localizations. We used L. monocytogenes, which thrives in the cytosol (15,21), L. pneumophila, which is found in specific replication vacuoles (20), and S. aureus and the coagulase-negative Staph-ylococcus epidermidis, which show a phagolysosomal localization in most cell types (1,3,13,40) but may also partially escape in the cytosol of endothelial or epithelial cells (17,37,52). We also assessed the intracellular activity of radezolid against different strains of S. aureus with various resistance mechanisms, including to linezolid.…”

Antistaphylococcal Activity of Dihydrophthalazine Antifolates, a Family of Novel Antibacterial Drugs

“…Infections caused by coagulase-negative staphylococci (CoNS), once considered rare, are becoming increasingly frequent, particularly in patients with indwelling medical devices and those who are immunocompromised, and such infections are associated with significant morbidity and mortality (40). The adhesion of Staphylococcus epidermidis to endothelial cells is enhanced at temperatures encountered during a moderate fever (27), and the internalization of CoNS by host cells (1,7,27) probably contributes to antibiotic failure and infection persistence in some patients. Glycopeptides, especially vancomycin, are the current standard of care for the empirical treatment of suspected methicillin-resistant staphylococcal infections, but staphylococci with reduced susceptibility, tolerance, or resistance to vancomycin have appeared in clinical settings (2,15,19,33), and their frequency is almost certainly underreported due to problems with identification and confusion over breakpoints (2,39).…”