Abstract

Purpose: This study aims to investigate the specific pathogenic properties or virulent determinant characteristics of uropathogenic Escherichia coli (UPEC) as bacterial adherence in tissue culture cells in vitro and the pathogenicity in animal model in vivo.
Materials and Methods: Thirty strains of E. coli were isolated from urine of patients with acute pyelonephritis. Four cell lines—HeLa cells, HEp-2 cells, A-498 cells, and J-82 cells—were used for bacterial adherence assay. Histologic examination and scanning electron microscopy examination of pyelonephritis or cystitis, which was caused by E. coli, in mice was performed.
Results: Sixteen (53.3%) strains of E. coli appeared to adhere to at least one or more kinds of four cell lines, and seven strains were able to adhere to all four cell lines. All of the tested E. coli strains were adhered to the mouse bladder and kidneys. The number of bacteria colonized in the kidney was greater than that of bladders in the following 5 strains of E. coli: TME104, TME107, TME113, TME306, and TME119. There was no difference in the number of bacteria colonized in the bladder and kidneys in the aspects of adherence patterns to tissue culture cells.
Conclusions: Although there was no best choice cell lines in the adherence assay to identify the adherence patterns, combined assays of in vitro cell culture and in vivo model of mouse urinary tract infection appeared to be efficient methods to investigate the role of bacterial adherence in the pathogenesis of UPEC.

• Keywords: Urinary tract infections; Virulence factors; <;em>;Escherichia coli<;/em>;