Production of pili, hemolysin and siderophores in the urinary isolates of Escherichia coli

Abstract

Introduction. Escherichia coli (E. coli) are the most frequent cause of the urinary tract infections. Uropathogenic E. coli (UPEC) produce virulence factors which enable them to survive in the urinary tract and cause an infection. Objective. The objective of this study was to determine phenotype characterization of E. coli isolated from outpatients’ urine in the region of Banja Luka over three-year period. In line with the objective, the following research tasks were set up: determining the production of type 1 fimbriae, P-pili, α-hemolysin and siderophores. Methods. A total of 417 urinary isolates and 100 control intestinal isolates were screened for virulence factors. Production of adhesions was confirmed by haemagglutination test. Plate haemolysis test was done for the detection of α-hemolysin, and siderophores production assay was carried out by using the method named chrome azurol sulfonate agar diffusion assay. Results. In the group of urinary isolates, almost 60% of isolates produced two or three virulence factors; only 3.8% produced none of the virulence factors. In the group of intestinal isolates, even 43% of isolates produced none of the virulence factors while 48% of isolates produced a single virulence factor and 9% produced two virulence factors. Conclusion. Urinary isolates E. coli express significantly more P-pili, α-hemolysin and siderophore than intestinal isolates (p<0.001). There was no significant difference in production of type 1 fimbriae among the urinary and intestinal isolates.

Keywords

• uropathogenic Escherichia coli
• bacterial adhesions
• iron chelating agents