An 18 kDa Scaffold Protein Is Critical for Staphylococcus epidermidis Biofilm Formation

PLoS Pathogens

Alexander R. Horswill¹  Paul D. Fey²  Carolyn R. Schaeffer²  Stephanie Bur³  Torsten Hartmann³  Markus Bischoff³  Rahel Decker⁴  Hanae A. Henke⁴  Martin Christner⁴  Holger Rohde⁴  Christoph Burdelski⁴  Melanie Zobiak⁴  Gefion Franke⁴  Katharina Saß⁴  Henning Büttner⁴  Bernd Zobiak⁵ 

[1] Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America;Department of Pathology and Microbiology, Center for Staphylococcal Research, University of Nebraska Medical Center, Omaha, Nebraska, United States of America;Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum des Saarlandes, Homburg, Germany;Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany;UKE Microscopy Imaging Facility, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany

关键词: Staphylococcus epidermidis;    Biofilms;    Bacterial biofilms;    Extracellular matrix;    Extracellular matrix proteins;    Catheters;    Polystyrene;    Cell walls;   

DOI  :  10.1371/journal.ppat.1004735

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Virulence of the nosocomial pathogen Staphylococcus epidermidis is crucially linked to formation of adherent biofilms on artificial surfaces. Biofilm assembly is significantly fostered by production of a bacteria derived extracellular matrix. However, the matrix composition, spatial organization, and relevance of specific molecular interactions for integration of bacterial cells into the multilayered biofilm community are not fully understood. Here we report on the function of novel 18 kDa Small basic protein (Sbp) that was isolated from S. epidermidis biofilm matrix preparations by an affinity chromatographic approach. Sbp accumulates within the biofilm matrix, being preferentially deposited at the biofilm–substratum interface. Analysis of Sbp-negative S. epidermidis mutants demonstrated the importance of Sbp for sustained colonization of abiotic surfaces, but also epithelial cells. In addition, Sbp promotes assembly of S. epidermidis cell aggregates and establishment of multilayered biofilms by influencing polysaccharide intercellular-adhesin (PIA) and accumulation associated protein (Aap) mediated intercellular aggregation. While inactivation of Sbp indirectly resulted in reduced PIA-synthesis and biofilm formation, Sbp serves as an essential ligand during Aap domain-B mediated biofilm accumulation. Our data support the conclusion that Sbp serves as an S. epidermidis biofilm scaffold protein that significantly contributes to key steps of surface colonization. Sbp-negative S. epidermidis mutants showed no attenuated virulence in a mouse catheter infection model. Nevertheless, the high prevalence of sbp in commensal and invasive S. epidermidis populations suggests that Sbp plays a significant role as a co-factor during both multi-factorial commensal colonization and infection of artificial surfaces.

【 授权许可】

CC BY