Abstract
Uropathogenic Escherichia coli (UPEC) fall within a larger group of isolates producing extraintestinal disease. UPEC express type 1 pili as a critical virulence determinant mediating adherence to and invasion into urinary tract tissues. Type 1 pili expression is under regulation by a family of site-specific recombinases, including FimX, which is encoded from a genomic island called PAI-X for pathogenicity island of FimX. Using a new multiplex PCR, fimX and the additional PAI-X genes were found to be highly associated with UPEC (144/173 = 83.2 %), and more prevalent in UPEC of lower urinary tract origin (105/120 = 87.5 %) than upper urinary tract origin (39/53 = 74 %; P<0.05) or commensal isolates (28 78 =" 36 %;" p≤0.0001). the fim-like recombinase gene fimx is the only family member that has a significant association with upec compared to commensal isolates. our results indicate pai-x genes, including the type 1 pili regulator gene fimx, are highly prevalent among upec isolates and have a strong positive correlation with genomic virulence factors, suggesting a potential role for pai-x in the extraintestinal pathogenic e. coli lifestyle.>
