Importance of the ebp (endocarditis- and biofilm-associated pilus) locus in the pathogenesis of Enterococcus faecalis ascending urinary tract infection.
BACKGROUND
We recently demonstrated that the ubiquitous Enterococcus faecalis ebp (endocarditis- and biofilm-associated pilus) operon is important for biofilm formation and experimental endocarditis. Here, we assess its role in murine urinary tract infection (UTI) by use of wild-type E. faecalis OG1RF and its nonpiliated, ebpA allelic replacement mutant (TX5475).


METHODS
OG1RF and TX5475 were administered transurethrally either at an ~1 : 1 ratio (competition assay) or individually (monoinfection). Kidney pairs and urinary bladders were cultured 48 h after infection. These strains were also tested in a peritonitis model.


RESULTS
No differences were observed in the peritonitis model. In mixed UTIs, OG1RF significantly outnumbered TX5475 in kidneys (P=.0033) and bladders (P< or =.0001). More OG1RF colony-forming units were also recovered from the kidneys of monoinfected mice at the 4 inocula tested (P=.015 to P=.049), and 50% infective doses of OG1RF for kidneys and bladder (9.1x10(1) and 3.5x10(3) cfu, respectively) were 2-3 log(10) lower than those of TX5475. Increased tropism for the kidney relative to the bladder was observed for both OG1RF and TX5475.


CONCLUSIONS
The ebp locus, part of the core genome of E. faecalis, contributes to infection in an ascending UTI model and is the first such enterococcal locus shown to be important in this site.
Singh
Kavindra V
KV
Center for the Study of Emerging and Reemerging Pathogens, Division of Infectious Diseases, University of Texas Medical School at Houston, Houston, TX 77030, USA.
Nallapareddy
Sreedhar R
SR
Murray
Barbara E
BE
D000483:Alleles; D000818:Animals; D021461:Animals, Outbred Strains; D018441:Biofilms / Q000254:growth & development*; D004195:Disease Models, Animal; D004697:Endocarditis, Bacterial / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000235:genetics / Q000472:pathogenicity*; D036781:Fimbriae Proteins / Q000235:genetics; D010861:Fimbriae, Bacterial / Q000235:genetics*; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006801:Humans; D007668:Kidney / Q000382:microbiology; D051379:Mice; D008813:Mice, Inbred ICR; D009154:Mutation; D009876:Operon; D010538:Peritonitis / Q000382:microbiology; D018805:Sepsis / Q000382:microbiology; D001743:Urinary Bladder / Q000382:microbiology; D014552:Urinary Tract Infections / Q000382:microbiology*
D036781:Fimbriae Proteins