Genotypic characteristics and biofilm formation among Escherichia coli isolates from Indian women with acute cystitis.

BACKGROUND

The purpose of present study was to characterize uropathogenic Escherichia coli (UPEC) associated with acute cystitis in Indian women.

METHODS

In this prospective descriptive study we investigated phylogenetic background and virulence genotypes for 15 genes by multiplex PCR and in vitro biofilm formation ability of 172 E. coli strains and explored possible association amongst them.

RESULTS

Most isolates (81, 47.1%) belonged to group B2 and A (50, 29.1%); few were from groups B1 (22, 12.7%) and D (19, 11.1%). The mean virulence scores of phylogroups A, B1, B2 and D were 3.3, 4.0, 4.6 and 4.9, respectively. We found higher prevalence of fimH, traT iutA, kpsMII, papG allele II and fyuA genes indicating putative role of adhesins, iron acquisition systems and protectins in causing bladder infection. Total 145 (84.3%) isolates produced biofilm; majority were weak biofilm producers and there was no significant difference in intensity and biofilm formation ability amongst various phylogroups or virulence scores. The phylogenetic distribution was different from western studies, including a lower prevalence of group B2 (dominant but not a majority), followed by group A, and some traditionally group B2-associated virulence genes were more prevalent in phylogroup A isolates.

CONCLUSIONS

Distribution of virulence genotypes and phylotypes can vary with geographical location and the isolates from western countries cannot be treated as prototypes for Asian cystitis isolates.