Transcriptome analysis of Enterococcus faecalis towards its adaption to surviving in the mouse intestinal tract
Enterococcus (E.) faecalis is a commensal in healthy humans, frequently found in a variety of fermented foods, and can serve as a probiotic. However, it has also been recognized as a pathogen causing diseases such as endocarditis, bacteremia and urinary tract infections. As known virulence factors are not limited to clinical isolates but widespread in many strains, additional fitness determinants should influence E. faecalis behavior in the host. We have performed a transcriptomic in vivo study with E. faecalis in the intestine of living mice to identify novel latent and adaptive fitness determinants within E. faecalis. The transcriptomic data derived from E. faecalis strain OG1RF monoassociated with wild type mice provide a first insight in the genes used to live as a commensal in the intestinal tract. Clear changes are observed as compared to growth under laboratory conditions (BHI broth) in the expression of genes involved in energy metabolism (e.g. dhaK and glpK pathway), transport and binding mechanisms (e.g. phosphoenolpyruvate carbohydrate PTS) as well as fatty acid metabolism (fab genes). This knowledge can be used to help explain its persistence in this environment, which is a prerequisite to cause infection in a compromised or inflamed host and possibly develop improved treatment strategies of the so far hard to cure infections. Overall design: Comparison of transcriptome data from Enterococcus faecalis growing in BHI broth and monoassociated mice