<i>fim</i>H<i> </i>adhesin-related gene and biofilm formation in uropathogenic <i>Escherichia coli</i> isolates from AL-Hillah/ Iraq

Uropathogenic Escherichia coli (UPEC) is the main causative agent of urinary tract infection and their ability to build biofilms leads to increases its severity and makes its removal difficult: The objective was to validate the species- specific primers designed to amplify the target sequence in E. coli genes (uidA encoding β-D-glucuronidase, yiaO encoding outer membrane protein and 16SrRNA) in contrast to clinical isolates previously identified as Shigella dysenteriae and Klebsiella pneumoniae and to investigate the possible relationship between the prevalence and sequence variations of fimH gene and the intensity of biofilm formation. Primers were designed based on the database available for E. coli in the National Center for Biotechnology Information (NCBI) for uidA, yaiO and 16SrRNA genes sequences. fimH virulence genes were investigated in fifty E. coli isolates of UTI patients by using PCR assay followed by sequence analysis of fimH among isolates with different degree of biofilm strength. Gel electrophoresis presented bands for uidA, yaiO, and 16SrRNA genes in all E. coli isolates. However, no bands were detected among isolates of Shigella dysenteriae and Klebsiella pneumoniae species. DNA sequence analysis for fimH gene revealed three positions of variations were repeatedly detected among strong biofilm former isolates leading to changes in their amino acid types. The uidA, yaiO, and 16SrRNA genes represented an ideal target for the identification of E. coli since all primers achieved exclusively related fragments. Variations of amino acid types among three biofilm phenotypic categories might be responsible for structural and functional heterogenicity of type 1 fimbria D-mannose specific adhesion protein.