Biofilm associated protein

S. aureus strains of bovine origin have been found to produce a surface protein known as biofilm associated protein (Bap) which supports biofdm formation... 

The predominant mechanism of biofilm accumulation in staphylococci involves polysaccharide intercellular adhesin (PIA) [60-66], S. epidermidis strains lacking this adhesin are also regularly isolated from biomaterial-related infections, a fact which prompted a search for an alternative, PIA-independent accumulation mechanism [51, 52, 60-62, 67, 68], The responsible molecule was identified as accumulation associated protein, Aap [69-71], and there may also be a role for additional proteinaceous intercellular adhesins [52], Aap has a similar-acting homolog, SasG, in S. aureus [72], adding to the accumulating evidence that proteinaceous intercellular adhesins are also of importance in S. aureus biofilm formation and device-related infection [52, 72-74],... 

It is important to note that the numbers yielded from quantifying total protein correlate to total biomass, but not necessarily to total cell numbers within a given biofilm. Cellular protein is correlated with cell number and is a relatively stable quantity however, extracellular protein is associated with cell activity and can be variable. The two types of protein cannot be distinguished from total protein extraction kits therefore, BBS activities that are normalized by amount of protein may underestimate per cell activities. A protocol and recommendations for optimization of protein extraction from BBS electrode samples are included in the subsequent sections. 

Teughels W, Van Assche N, SUepen I, Quirynen M. Effect of material characteristics and/ or surface topography on biofilm development. Clin Oral Implants Res 2006 17 68-81. Sun D, Accavitti MA, Bryers JD. Inhibition of biofilm formation by monoclonal antibodies against Staphylococcus epidermidis RP62A accumulation-associated protein. Clin Diagn Lab Immunol 2005 12 93-100. 

Lactoferrin, a protein contained in tears, increases the activity of vancomycin against biofilms of strains of Staphylococcus epidermidis and may be therapeutically helpful in the treatment of infections such as endophthalmitis associated with intraocular lenses (7). 

At present the origin of the new higher-temperature glass-transition that occurred in the polyurethane modules after four weeks in vivo is unknown. Calcium phosphate precipitates and biofilms with high protein density have been observed on orthodontic modules after three weeks in vivo [52], and some diffusion of ion species from salivary fluid into the polymer matrix of the polyurethane modules would be expected. Further DSC study of clinically used orthodontic modules is needed to determine the origins of the new higher-temperature glass-transition and the associated endothermic peak. 

The increasing growth of neuropathologies, especially in Western countries, which are associated with prions and other aggregates of misfolded proteins, has become a serious concern in biomedical research. Amyloid fibril formation, for instance, appears to be the critical step in Alzheimer s disease. Ultrasound has been used to evaluate both the formation and disruption of amyloids, although contradictory results may be found as sonication parameters are often overlooked, as in biofilms. 

A wide variety of natural and synthetic materials have been used for biomedical applications. These include polymers, ceramics, metals, carbons, natural tissues, and composite materials (1). Of these materials, polymers remain the most widely used biomaterials. Polymeric materials have several advantages which make them very attractive as biomaterials (2). They include their versatility, physical properties, ability to be fabricated into various shapes and structures, and ease in surface modification. The long-term use of polymeric biomaterials in blood is limited by surface-induced thrombosis and biomaterial-associated infections (3,4). Thrombus formation on biomaterial surface is initiated by plasma protein adsorption followed by adhesion and activation of platelets (5,6). Biomaterial-associated infections occur as a result of the adhesion of bacteria onto the surface (7). The biomaterial surface provides a site for bacterial attachment and proliferation. Adherent bacteria are covered by a biofilm which supports bacterial growth while protecting them from antibodies, phagocytes, and antibiotics (8). Infections of vascular grafts, for instance, are usually associated with Pseudomonas aeruginosa Escherichia coli. Staphylococcus aureus, and Staphyloccocus epidermidis (9). 

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