A Fibrinogen-Binding Protein of Staphylococcus epidermidis

Abstract

The present study reports on fibrinogen (Fg) binding ofStaphylococcus epidermidis. Adhesion of differentS. epidermidis strains to immobilized Fg was found to vary significantly between different strains, and the component responsible was found to be proteinaceous in nature. To further characterize the Fg-binding activity, a shotgun phage display library covering the S. epidermidis chromosome was constructed. By affinity selection (panning) against immobilized Fg, a phagemid clone, pSEFG1, was isolated, which harbors an insert with an open reading frame of ∼1.7 kilobases. Results from binding and inhibition experiments demonstrated that the insert of pSEFG1 encodes a specific Fg-binding protein. Furthermore, affinity-purified protein encoded by pSEFG1 completely inhibited adhesion of S. epidermidis to immobilized Fg. By additional cloning and DNA sequence analyses, the complete gene, termed fbe, was found to consist of an open reading frame of 3,276 nucleotides encoding a protein, called Fbe, with a deduced molecular mass of ∼119 kDa. With a second phage display library made from another clinical isolate ofS. epidermidis, it was possible to localize the Fg-binding region to a 331-amino-acid-long fragment. PCR analysis showed that the fbe gene was found in 40 of 43 clinical isolates of S. epidermidis. The overall organization of Fbe resembles those of other extracellular surface proteins of staphylococci and streptococci. Sequence comparisons with earlier known proteins revealed that this protein is related to an Fg-binding protein of Staphylococcus aureus called clumping factor.

<I>Staphylococcus epidermidis</I> device-related infections: pathogenesis and clinical management

“…S. epidermidis produces surface proteins that are involved in the interaction with host proteins of the extracellular matrix present in the host-derived conditioning film, and therefore in biofilm formation (von Eiff et al 2002). Examples include the surface associated autolysin AtlE , which promotes binding to polystyrene surfaces and is also involved in vitronectin adhesion, the fibrinogen-binding Fbe (Nilsson et al 1998) and SdrG, SdrF and SdrH cell-surface-associated proteins (McCrea et al 2000). Fbe, SdrG, SdrF and SdrH are all members of the recently identified protein family, the serine-aspartate (SD)-repeat-containing (Sdr) family of cellwall-anchored surface proteins (von Eiff et al 2002), which interact with extracellular matrix proteins.…”

Genome‐based analysis of virulence genes in a non‐biofilm‐forming Staphylococcus epidermidis strain (ATCC 12228)

“…Other adhesin genes described in S. epidermidis clinical isolates, such as the atIE gene and the fbe gene (Nilsson et al, 1998) are present in ATCC 12228. Recently, an extracellular-matrix-binding protein Embp has been identified as the fibronectin binding protein of Staphylococcus epidermidis in strain NCTC 11047 (Williams et al, 2002), and this protein is also found in Staphylococcus aureus (Hussain et al, 2001).…”

A von Willebrand factor-binding protein from Staphylococcus lugdunensis

“…Casein, human serum albumin (HSA) and human fibronectin were from Sigma, and human fibrinogen was from IMCO Corp. Ltd. (Stockholm, Sweden). The fibrinogen-binding part (amino acids 52-646) of protein Fbe [14] of Staphylococcus epidermidis was expressed in E. coli following the same general scheme as described below under Section 2.5.…”