Elucidating the Relationships of Cell Surface Biophysical Properties on Cellular Adhesion and Biofilm Formation of Laboratory and Uropathogenic Escherichia coli Strains

Presenter

Marcos Lora

Campus

UMass Amherst

Sponsor

Lauren B. Andrews, Department of Chemical Engineering, UMass Amherst

Schedule

Session 4, 2:30 PM - 3:15 PM [Schedule by Time][Poster Grid for Time/Location]

Location

Poster Board A49, Campus Center Auditorium, Row 3 (A41-A60) [Poster Location Map]

Abstract

Bacterial cell adhesion to surfaces, particularly relevant on medical devices, often leads to biofilm formation and antibiotic-resistant infections. Current biofilm mitigation strategies are constrained by toxicity issues and a lack of detailed understanding of the genetic and signaling pathways that underlie cellular adhesion. This study aims to deepen our understanding of cellular adhesion by examining the relationships of biophysical cell surface properties (hydrophobicity and surface charge) to biomaterial surface adhesion. We selected a uropathogenic E. coli CFT073 clinical strain for this study. We employed CRISPR interference (CRISPRi) gene repression to investigate the relationship between cellular adhesion and expression of seven genes  encoding extracellular surface appendages and membrane-bound proteins  (fimH, csgA, bhsA, lpcA, cpxR, nlpE, wcaF). Additionally, we conducted assays to measure the cell surface hydrophobicity of CFT073 by using CRISPRi-based repression and employing E.coli strain BW25113 with gene knockouts as a control. Our experiments revealed that for the wildtype strains, CFT073 had a more hydrophobic surface than BW25113. However, gene repression for any of the targeted genes in CFT073 did not significantly change the hydrophobicity (p > 0.05), contradicting published studies and despite conferring reduced adhesion to hydrophobic and hydrophilic biomaterials in our experiments. Interestingly, the knockout fimH gene in BW25113 resulted in a 2.5-fold greater decrease in hydrophobicity compared to the repression of the fimH gene in CFT073. Ongoing studies will focus on the relationship between the expression of these genes and cell surface charge by conducting zeta potential assays, which may inform new approaches to mitigate biofilm-associated infections.

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Keywords

CRISPRi, Uropathogenic E.coli , Genetic Engineering, Biofilm

Research Area

Biological Organisms

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