Virulence-associated factors in Escherichia coli strains isolated from urinary tract infections

Escherichia coli is one of the most frequent causes of extra-intestinal diseases including urinary tract infections (UTI). E.coli is the most frequent urinary pathogen isolated from 50% 90% of all uncomplicated urinary tract infections. (Steadman and, Topley, 1998). It is now recognized that there are subsets of faecal E. coli , which can colonize periurethral area, enter urinary tract and cause symptomatic disease. These are currently defined as uropathogenic E. coli .( Vagarali et al., 2008). The different virulence factors include adhesins, hemolysin production and siderophore production. Fimbriae mediate the ability of E. coli to adhere to the uroepithelium, thereby resisting elimination by the flow of urine. Adhesion is therefore considered to be an important step in the pathogenesis of UTI ( Struve and Krogfelt, 1999).