Abstract
BackgroundEnterococci are the third most common cause of healthcare-associated infections, which include urinary tract infections, bacteremia and endocarditis. Cell-surface structures such as lipoteichoic acid (LTA) have been poorly examined in E. faecalis, especially with respect to urinary tract infections (UTIs). The dlt operon is responsible for the D-alanylation of LTA and includes the gene dltA, which encodes the D-alanyl carrier protein ligase (Dcl). The involvement of LTA in UTI infection by E. faecalis has not been studied so far. Here, we examined the role of teichoic acid alanylation in the adhesion of enterococci to uroepithelial cells.ResultsIn a mouse model of urinary tract infection, we showed that E. faecalis 12030ΔdltA mutant colonizes uroepithelial surfaces more efficiently than wild type bacteria. We also demonstrated that this mutant adhered four fold better to human bladder carcinoma cell line T24 compared to the wild type strain. Bacterial adherence could be significantly inhibited by purified lipoteichoic acid (LTA) and inhibition was specific.ConclusionIn contrast to bacteraemia model and adherence to colon surfaces, E. faecalis 12030ΔdltA mutant colonized uroepithelial surfaces more efficiently than wild-type bacteria. In the case of the uroepithelial surface the adherence to specific host cells could be prevented by purified LTA. Our results therefore suggest a novel function of alanylation of LTA in E. faecalis.
Highlights
Enterococci are the third most common cause of healthcareassociated infections, which include urinary tract infections, bacteremia and endocarditis
Like other Gram-positive bacteria (e.g., Staphylococcus aureus), the surface of E. faecalis is rich in exposed adhesins that mediate binding to human receptors or to various components of the extracellular matrix (ECM); they are considered a member of MSCRAMM-microbial surface component–recognizing adhesive matrix molecules [3]
While urinary tract infections (UTIs)-specific virulence factors of E. coli have been studied extensively, relatively little is known about E. faecalis cell-surface structures with respect to UTIs [7–10 & 11]
Summary
Enterococci are the third most common cause of healthcareassociated infections, which include urinary tract infections, bacteremia and endocarditis. Risk groups for invasive enterococcal infections include neonates, Intensive Care Unit (ICU) patients and immunocompromised hosts [1]. MSCRAMMs are cell wall–anchored surface proteins that have characteristic immunoglobulin-like folds [4]. Cell-surface structures such as lipoteichoic acid (LTA) have been poorly examined in E. faecalis, especially with respect to urinary tract infections (UTIs). The involvement of LTA in UTI infection by E. faecalis has not been studied so far. We examined the role of teichoic acid alanylation in the adhesion of enterococci to uroepithelial cells
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
