Evaluation of cell surface hydrophobicity and biofilm formation as pathogenic determinants among ESBL producing uropathogenic Escherichia coli

Abstract

The attachment of the bacteria to the host cell and ability to invade the cell are regarded as important steps in the infectious process. The hydrophobicity of the microbial surface plays a critical role in the adherence of bacteria to the surface. The ability of biofilm formation can increase survival chance of microorganism, as cell growing in biofilm are highly resistant to the components of the immune system and many antimicrobial agents. Infection caused by ESBL- producers are associated with severe adverse outcomes and may be related to increased virulence of these strains.: A total of 100 urinary were selected for the study, of which 50 strains were from ESBL producers and 50 from non- ESBL-producing uropathogenic(UPEC) strains. The urinary isolates that were resistant to at least one of the three indicator cephalosporins (cefotaxime, cefpodoxime and ceftazidime) were tested for ESBL production by quantitative E-strip method. All the 100 urinary strains were tested for cell surface hydrophobicity (CSH) by salt aggregation method and Biofilm production by tissue culture plate method.Among ESBL producers, 19 (38%) were CSH positive and 34 (68%) were biofilm producers. However among non-ESBL producers, 05 (10%) were CSH positive and 12 (24%) were biofilm producers. Statistically significant difference (<0.001) was seen in the occurrence of CSH and biofilm production between ESBL and non ESBL producing UPEC isolates.In the present study, it was found that the ESBL producing isolates had a higher ability to form biofilm and CSH; both of them are among the important virulence factors associated with cell surface adherence which is the first step in bacterial infection.