title: Interaction between atypical microorganisms and E. coli in catheter-associated urinary tract biofilms.
abstract: Most biofilms involved in catheter-associated urinary tract infections (CAUTIs) are polymicrobial, with disease causing (eg Escherichia coli) and atypical microorganisms (eg Delftia tsuruhatensis) frequently inhabiting the same catheter. Nevertheless, there is a lack of knowledge about the role of atypical microorganisms. Here, single and dual-species biofilms consisting of E. coli and atypical bacteria (D. tsuruhatensis and Achromobacter xylosoxidans), were evaluated. All species were good biofilm producers (Log 5.84-7.25 CFU cm(-2) at 192 h) in artificial urine. The ability of atypical species to form a biofilm appeared to be hampered by the presence of E. coli. Additionally, when E. coli was added to a pre-formed biofilm of the atypical species, it seemed to take advantage of the first colonizers to accelerate adhesion, even when added at lower concentrations. The results suggest a greater ability of E. coli to form biofilms in conditions mimicking the CAUTIs, whatever the pre-existing microbiota and the inoculum concentration.
authors.affiliation: a Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), Department of Chemical Engineering, Faculty of Engineering , University of Porto , Rua Dr Roberto Frias, 4200-465 Porto , Portugal.
authors.forename: Andreia S
authors.initials: AS
authors.lastname: Azevedo
authors.forename: Carina
authors.initials: C
authors.lastname: Almeida
authors.forename: Luís F
authors.initials: LF
authors.lastname: Melo
authors.forename: Nuno F
authors.initials: NF
authors.lastname: Azevedo
mesh_terms: D042441:Achromobacter denitrificans / Q000254:growth & development / Q000502:physiology*; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D042742:Delftia / Q000254:growth & development / Q000502:physiology*; D004926:Escherichia coli / Q000254:growth & development / Q000502:physiology*; D062885:Urinary Catheters / Q000382:microbiology*
keywords: Escherichia coli; atypical species; multispecies biofilms; urinary catheters; urinary tract infections