Interaction between atypical microorganisms and E. coli in catheter-associated urinary tract biofilms

• Published in: Biofouling (Chur, Switzerland) Switzerland), 2014-09, Vol.30 (8), p.893-902
• Main Authors: Azevedo, Andreia S., Almeida, Carina, Melo, Luís F., Azevedo, Nuno F.
• Format: Article
• Language: English
• Subjects: Achromobacter denitrificans - growth & development; Achromobacter denitrificans - physiology; Atypical species; Bacterial Adhesion; Biofilms - growth & development; Delftia - growth & development; Delftia - physiology; Escherichia coli; Escherichia coli - growth & development; Escherichia coli - physiology; Multispecies biofilms; Science & Technology; Urinary catheters; Urinary Catheters - microbiology; Urinary tract infections
• ISSN: 0892-7014; 1029-2454
• DOI: 10.1080/08927014.2014.944173

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.