Transcriptomic analysis of Staphylococcus epidermidis biofilm-released cells upon interaction with human blood circulating immune cells and soluble factors

Abstract

[Excerpt] Background: The colonization of indwelling medical devices by biofilm-forming bacteria is one of the major causes of healthcare-associated infections (Percival et al., 2015). Staphylococcus epidermidis, a biofilm-forming commensal bacterium that inhabits human skin and mucosae, is considered one of most important causes of medical devices-related infections, being particularly associated with the use of intravascular catheters (Mack et al., 2013). Although S. epidermidis biofilms are classically associated with the development of chronic infections (Costerton et al., 1999), the release of cells from the biofilm has been associated with onset of acute infections such as embolic events of endocarditis (Pitz et al., 2011), bacteremia, or even septicemia (Cole et al., 2016). Bloodstream infections caused by S. epidermidis are typically indolent and difficult to eradicate significantly increasing patient’s morbidity (Kleinschmidt et al., 2015) and mortality among immunocompromised (Khashu et al., 2006) and immunosuppressed patients (Bender and Hughes,1980).Inaddition,thecostsassociatedwiththediagnosisandtreatmentofthesesecondary infections is estimated to be approximately $20,000 per occurrence (Kilgore and Brossette, 2008). Henceforth, it is imperative to redefine strategies for the management of the pathologic events associated with biofilm disassembly. Since bloodstream infections are one of the most frequent complications caused by S. epidermidis biofilm disassembly (Cole et al., 2016), a comprehensive analysis of the interplay between S. epidermidis biofilm-released cells (BRC) and hosts’ blood components would be invaluable. Herein, as the first step toward the understanding of this interaction,wehavecharacterized,usingRNAsequencing(RNAseq)technology,thetranscriptome of S. epidermidis BRC upon interaction with whole human blood, polymorphonuclear, or mononuclear leukocytes and plasma.