title: Genotypic and phenotypic diversity in Enterococcus faecalis: is agar invasion a pathogenicity score?
abstract: OBJECTIVE
  The main objective of the present study is to analyze different genotypic and phenotypic traits related to virulence in Enterococcus faecalis, as well as evaluated the agar invasion phenotype in a collection of isolates with different clinical origins.
  
  
  METHODS
  Seventy-nine E. faecalis isolates, with invasive and non-invasive clinical origins, have been used in this work. Presence of cytolysin activator (cylA), gelatinase (gelE), surface protein (esp), aggregation substance (asa1), endocarditis antigen (efaA), and collagen-binding protein (ace) have been analyzed by PCR. Phenotypic characterization included gelatinase activity, haemolysin production, biofilm formation and agar invasion.
  
  
  RESULTS
  All the isolates tested harboured at least one of the virulence determinants. The 95.5% of isolates from haematologic samples were positive for agar invasion test, significantly higher than isolates from non-invasive diseases. A significant reduction in relative invasion area was observed in three selected agar-invasive strains after 15 serial passages.
  
  
  CONCLUSIONS
  It has been observed a significant high prevalence of agar-invasion positive isolates among strains belonged to haematological samples. Agar invasiveness is reduced after adaptation of clinical isolates to laboratory conditions, showing that agar invasion phenotype can be modulate by culture conditions as other virulence factors observed in different bacterial species.
authors.affiliation: Fabio Cafini, Medicine Department - Microbiology Area, School of Medicine, Complutense University, Avda Complutense s/n, 28040, Madrid, Spain. fcafini@med.ucm.es.
authors.forename: F
authors.initials: F
authors.lastname: Cafini
authors.forename: F
authors.initials: F
authors.lastname: Gómez-Aguado
authors.forename: M T
authors.initials: MT
authors.lastname: Corcuera
authors.forename: C
authors.initials: C
authors.lastname: Ramos
authors.forename: P
authors.initials: P
authors.lastname: Bas
authors.forename: L
authors.initials: L
authors.lastname: Collado
authors.forename: M L
authors.initials: ML
authors.lastname: Gómez-Lus
authors.forename: J
authors.initials: J
authors.lastname: Prieto
mesh_terms: D000362:Agar; D016470:Bacteremia / Q000382:microbiology; D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity*; D018093:Gelatinases / Q000096:biosynthesis / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D010641:Phenotype; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D006460:Hemolysin Proteins; D037521:Virulence Factors; D000362:Agar; D018093:Gelatinases