title: In vitro adhesion to human cells by viable but nonculturable Enterococcus faecalis.
abstract: The ability of viable but nonculturable (VBNC) Enterococcus faecalis to adhere to Caco-2 and Girardi heart cultured cells and to urinary tract epithelial cells (ECs) was studied. Enterococci were harvested during the vegetative growth phase (early exponential and stationary), in the VBNC state, and after recovery of the ability to divide. VBNC bacteria maintained their adherence capability but the efficiency of attachment was reduced by about 50 to 70%, depending on the target cell employed. The decrease was transient, since enterococci that regained their culturability showed adherence values similar to those observed for actively growing cells. Analysis of the invasive properties of E. faecalis revealed that the VBNC state caused a decrease in the number of bacteria that entered the cultured HEK cells as a result of the reduction in the number of adhering bacteria. These results highlight the importance of studies of the VBNC phenomenon, with respect to both microbial survival in the environment and the impact on human health.
authors.affiliation: Istituto di Microbiologia, Università di Ancona, via Ranieri Monte d'Ago, 60131 Ancona, Italy. pruzzo@mbox.ulisse.it
authors.forename: Carla
authors.initials: C
authors.lastname: Pruzzo
authors.forename: Renato
authors.initials: R
authors.lastname: Tarsi
authors.forename: Maria Mar
authors.initials: MM
authors.lastname: Lleò
authors.forename: Caterina
authors.initials: C
authors.lastname: Signoretto
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Zampini
authors.forename: Rita R
authors.initials: RR
authors.lastname: Colwell
authors.forename: Pietro
authors.initials: P
authors.lastname: Canepari
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology*; D018938:Caco-2 Cells; D002478:Cells, Cultured; D013293:Enterococcus faecalis / Q000254:growth & development / Q000502:physiology*; D004848:Epithelium / Q000382:microbiology; D006321:Heart / Q000382:microbiology; D006801:Humans; D014552:Urinary Tract Infections / Q000382:microbiology