Bacterial strains were grown overnight as shaking cultures in M9 minimal medium. Strains which produced a negative result in this assay were enriched for type 3 fimbriae production by three successive rounds of 48 h static growth in M9 minimal medium and then re-tested. CBL0137 purchase Biofilm study Biofilm formation on polyvinyl chloride (PVC) surfaces was monitored by using 96-well microtitre plates (Falcon) essentially as previously described [16]. Briefly, cells were grown for

24 h in M9 minimal medium (containing 0.2% glucose) or 48 h in synthetic urine at 37°C under shaking conditions, washed to remove unbound cells and stained with crystal violet. Quantification of biofilm TH-302 in vivo mass was performed by addition of acetone-ethanol (20:80) and measurement of the dissolved crystal violet at an optical density of 595 nm. All experiments were performed in a minimum of eight replicates. Immunoblotting and immunogold-labelled electron microscopy Crude cell lysates were prepared from overnight cultures and boiled in acid as previously described [14]. Protein samples were analysed by SDS-PAGE and western blotting as previously described [52] employing a type 3 fimbriae specific antiserum. Immunogold labelling was performed using the same Type 3 fimbriae specific antiserum as previously described

[14]. Cells were examined under a JEOL JEM1010 TEM operated at 80 kV. Images were captured using an mTOR inhibitor analysis Megaview clonidine digital camera. Phylogenetic and sequence analysis PCR products were generated from an internal region of mrkA (416 bp), mrkB (243 bp), mrkC (657 bp) and mrkD (778), respectively, from each of the 33 CAUTI strains and sequenced on both strands. These sequences correspond to nucleotides 112 to 530 of mrkA, 66 to 308 of mrkB, 173 to 829 of mrkC and 157 to 934 of mrkD in the reference strain K. pneumoniae MGH78578 (CP000647). Individual and concatenated gene fragments from the 33 CAUTI strains (and six

additional mrk sequences available at GenBank from strains causing other infections; accession numbers: CP000647, EU682505, CP000964, M55912, CP000822, EU370913) were aligned using ClustalX [53], and subjected to phylogenetic analysis using PHYLIP [54]. Maximum likelihood (ML) trees were built from a concatenated alignment of 2104 nucleotides (comprising 1269 conserved sites and 775 informative sites) using the dnaml algorithm in PHYLIP [54]. A consensus tree of 500 ML bootstrap replicates was prepared using the majority rule method as implemented by Splitstree version 4 [55, 56]. We were unable to amplify mrkD from E. coli M202 and only used the mrkABC concatenated fragments in the analysis. For comparative analysis, the complete mrk cluster (and adjacent regions) from E. coli ECOR28, C. freundii M46 and K. oxytoca M126 were amplified using an inverse PCR strategy and sequenced.