icaand beyond: biofilm mechanisms and regulation inStaphylococcus epidermidisandStaphylococcus aureus

Abstract

Recent progress in elucidating the role of the icaADBC-encoded polysaccharide intercellular adhesin (PIA) or polymeric N-acetyl-glucosamine (PNAG) in staphylococcal biofilm development has in turn contributed significantly to our understanding of the pathogenesis of device-related infections. Nevertheless, our understanding of how the ica locus and PIA/PNAG biosynthesis are regulated is far from complete and many questions remain. Moreover, beyond ica, evidence is now emerging for the existence of ica-independent biofilm mechanisms in both Staphylococcus aureus and Staphylococcus epidermidis. Teichoic acids, which are a major carbohydrate component of the S. epidermidis biofilm matrix and the major cell wall autolysin, play an important role in the primary attachment phase of biofilm development, whereas the cell surface biofilm-associated protein and accumulation-associated protein are capable of mediating intercellular accumulation. These findings raise the exciting prospect that other surface proteins, which typically function as antigenic determinants or in binding to extracellular matrix proteins, may also act as biofilm adhesins. Given the impressive array of surface proteins expressed by S. aureus and S. epidermidis, future research into their potential role in biofilm development either independent of PIA/PNAG or in cooperation with PIA/PNAG will be of particular interest.

Major components of orange oil inhibit Staphylococcus aureus growth and biofilm formation, and alter its virulence factors

“…The role of IcaA in conjunction with IcaD is to produce polysaccharide intercellular adhesion, while the role of IcaB is to deacetylate it to attach to surfaces and other cells. Downregulating icaA and icaB may interfere with cell-to-cell attachment and the growth of biofilms (O'Gara, 2007).…”

Evaluation of Protein Adsorption on Atmospheric Plasma Deposited Coatings Exhibiting Superhydrophilic to Superhydrophobic Properties

“…Alternative confirmation of results obtained by ellipsometry which indicated minimal protein attachment to superhydrophobic surfaces was facilitated by bacterial attachment studies. Bacterial interactions with implanted biomaterials represent the first step in the development of biofilm-associated, device-related infections [46]. Surface hydrophobicity plays an important role in these interactions as does the conditioning film of serum and tissue proteins such as Fg and Fn, which is rapidly deposited on implanted biomaterials [46].…”

“…Bacterial interactions with implanted biomaterials represent the first step in the development of biofilm-associated, device-related infections [46]. Surface hydrophobicity plays an important role in these interactions as does the conditioning film of serum and tissue proteins such as Fg and Fn, which is rapidly deposited on implanted biomaterials [46]. Bacterial pathogens express surface proteins that promote binding to Fg, Fn and a range of other serum and extracellular matrix proteins [46].…”

“…Surface hydrophobicity plays an important role in these interactions as does the conditioning film of serum and tissue proteins such as Fg and Fn, which is rapidly deposited on implanted biomaterials [46]. Bacterial pathogens express surface proteins that promote binding to Fg, Fn and a range of other serum and extracellular matrix proteins [46]. Thus, bacterial attachment experiments were carried out using an S. aureus (SH1000), which is known to bind specifically to Fg before and after protein adsorption experiments to identify any potential increase in bacterial attachment due to an adsorbed protein layer.…”

Hydrogen peroxide induced repression of icaADBC transcription and biofilm development in Staphylococcus epidermidis

“…11 Specific environmental conditions such as osmotic stress, ethanol, glucose, subinhibitory concentrations of certain antibiotics, anaerobiosis, and iron limitation can activate the ica operon leading to increased biofilm formation. 12 Oxygen stress is an environmental challenge presented to bacteria in the development of biomaterialrelated infection. The oxygen rich environment of the operative field is derived mainly from endogenous sources.…”