title: Adhesion of Enterococcus faecalis in the nonculturable state to plankton is the main mechanism responsible for persistence of this bacterium in both lake and seawater.
abstract: The presence of enterococci in lake and seawater in an 18-month survey comparing molecular (PCR and quantitative PCR) and culture methods was evaluated, as well as the possibility that zooplankton could act as reservoirs for enterococci. Samples of both water and zooplankton were collected monthly from a Lake Garda site and an Adriatic Sea site. In lake water, the positive samples numbered 13 of 54 (24%) by culture and 32 of 54 (59%) when PCR was applied. In seawater, they numbered 0 of 51 by culture and 18 of 51 (35%) by PCR. Enterococci were found either totally bound to plankton or totally in water, depending on the presence or absence of plankton, respectively. These results clearly indicate that the PCR assay is a powerful tool for detecting fecal indicators and pathogens in the environment, thus providing a much more sensitive method than culture.
authors.affiliation: Sezione di Microbiologia, Dipartimento di Patologia, Università di Verona, Verona, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Signoretto
authors.forename: Gloria
authors.initials: G
authors.lastname: Burlacchini
authors.forename: Maria del Mar
authors.initials: MM
authors.lastname: Lleò
authors.forename: Carla
authors.initials: C
authors.lastname: Pruzzo
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Zampini
authors.forename: Luigi
authors.initials: L
authors.lastname: Pane
authors.forename: Giorgio
authors.initials: G
authors.lastname: Franzini
authors.forename: Pietro
authors.initials: P
authors.lastname: Canepari
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis; D013293:Enterococcus faecalis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D005618:Fresh Water / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012623:Seawater / Q000382:microbiology*; D015048:Zooplankton / Q000382:microbiology*
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial