title: Relative contributions of Ebp Pili and the collagen adhesin ace to host extracellular matrix protein adherence and experimental urinary tract infection by Enterococcus faecalis OG1RF.
abstract: Previous studies have demonstrated that the ebp operon and the ace gene of Enterococcus faecalis, encoding endocarditis- and biofilm-associated pili and an adhesin to collagen of E. faecalis, respectively, are both important in experimental urinary tract infections (UTI) and endocarditis. We have also shown that growth of E. faecalis in brain heart infusion (BHI) serum enhances Ebp pilus and Ace production and increases adherence to several host extracellular matrix proteins. Here, we report that deletion of ebpABC almost eliminated serum-elicited adherence to fibrinogen (P < 0.0001), resulted in moderate reduction in adherence to collagen (P < 0.05), and had no effect on fibronectin adherence relative to that of wild-type OG1RF. An OG1RFΔaceΔebpABC double mutant showed further reduced collagen adherence versus that of the OG1RFΔace or OG1RFΔebpABC mutants (P < 0.001). These results were corroborated by complementation and/or studies with native pilus-enriched surface extracts and a collagen-secreting 3T6 fibroblast cell line, as well as antibody inhibition. In the UTI model, both the OG1RFΔace and OG1RFΔaceΔebpABC mutants were found to be significantly attenuated compared to the wild type; however, no significant differences were observed between individual ace or ebp mutants and the OG1RFΔaceΔebpABC mutant. In summary, these data implicate the Ebp pili as having some role in collagen adherence, albeit less than that of Ace, and a very major role in fibrinogen adherence, which may explain in part the importance of these pili in experimental endocarditis. The OG1RFΔaceΔebpABC mutant was attenuated in the UTI model, although not significantly more so than the Δace or ΔebpABC mutants, suggesting involvement of other E. faecalis factors in urinary tract colonization or infection.
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Center for the Study of Emerging and Reemerging Pathogens, University of Texas Medical School, Houston, Texas 77030, USA.
authors.forename: Sreedhar R
authors.initials: SR
authors.lastname: Nallapareddy
authors.forename: Kavindra V
authors.initials: KV
authors.lastname: Singh
authors.forename: Jouko
authors.initials: J
authors.lastname: Sillanpää
authors.forename: Meng
authors.initials: M
authors.lastname: Zhao
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Murray
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003094:Collagen / Q000378:metabolism; D013293:Enterococcus faecalis / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D005798:Genes, Bacterial; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D051379:Mice; D009154:Mutation; D016133:Polymerase Chain Reaction; D014552:Urinary Tract Infections / Q000382:microbiology*
chemical_list: C121675:Ace protein, Enterococcus; D001426:Bacterial Proteins; D002352:Carrier Proteins; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D005340:Fibrinogen; D003094:Collagen