Microbiology Insights 2011:4 21–27 doi: 10.4137/MBI.S8526 This article is available from http://www.la-press.com. © the author(s), publisher and licensee Libertas Academica Ltd. This is an open access article. Unrestricted non-commercial use is permitted provided the original work is properly cited. Open Access Full open access to this and thousands of other papers at http://www.la-press.com. Microbiology Insights OrIgInAL reSeArch Microbiology Insights 2011:4 21 cranberry (Vaccinium macrocarpon) changes the surface hydrophobicity and bioflm formation of E. coli Jose Uberos 1 , Ishan Iswaldi 2 , rocio rodríguez Belmonte 1 , Antonio Segura-carretero 2 , Verónica Fernández-Puentes 1 , Antonio Molina-carballo 1 and Antonio Muñoz-hoyos 1 1 Department of Paediatrics. Faculty of Medicine, University of granada. 2 Department of Analytical chemistry, Faculty of Sciences, University of granada, Spain. corresponding author email: uberosfernandez@terra.es Abstract: Cranberry has been shown useful in the prevention of urinary infection by E. coli. In this study, we examined the changes in the hydrophobicity of P fmbriated E. coli and bioflm formation after incubation with commercial cranberry syrup extract at various concentrations. After incubating a bacterial suspension with cranberry at dilutions of 1:100 and 1:1000, tests of haemagglutination inhibition, surface hydrophobicity and bioflm formation were carried out. The surface hydrophobicity of E. coli decreased signifcantly after incubation with cranberry and this effect was not modifed by the culture medium. Bioflm formation was inhibited after incubation with cranberry syrup and this effect was dependent on the culture medium. Thus, in some circumstances cranberry can modify nonspecifc adhesive properties of E. coli. In previous studies, cranberry has only been implicated in the inhibition of P-fmbriated E. coli, but our observations show that it acts by modifying adhesive properties under P-related fmbriae. Keywords: cranberry syrup, E. coli, bioflm, hydrophobicity, P-fmbriae