ARS | Publication request: Strain level differences in E. coli transport, cell surface and adhesion characteristics

Submitted to: Microbial Ecology International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2010
Publication Date: July 8, 2010
Citation: Cook, K.L., Bolster, C.H., Walker, S., Ayers, K., Marcus, I. 2010. Strain level differences in E. coli transport, cell surface and adhesion characteristics. Microbial Ecology International Symposium. Abstract only.

Technical Abstract: Given the importance of E. coli as an indicator of fecal contamination, it is imperative that genotypic and phenotypic variability among strains of E. coli from the same host and/or environmental niche are understood. The goal of this study was to evaluate the effect of strain level differences on the attachment and transport of E. coli through porous media. Using selective plating, 339 E. coli isolates were obtained from swine lagoon slurry and isolates were characterized by BOX PCR analysis of DNA extracts. Eight isolates, representing 81% of the diversity of E. coli isolates, were selected for transport studies and cell surface characterization. Cell properties such as (electrophoretic mobility, hydrophobicity, charge density), the occurrence of surface structures (lipopolysaccharides, autotransporter proteins, and fimbriae) and the transport behavior of each isolate was assessed. Our results show a large diversity in cell properties (hydrophobicity ranging from 6 to 81% and Zeta potential ranging from – 2.0 to – 46 mV) and transport behavior (percent recovery of cells eluted from the columns ranged from 46% to nearly 100%) for the different E. coli isolates. Correlation of phenotypic behavior with genotype shows that strains that had high sticking efficiencies to the quartz sand grains were also uniquely possessive of genes for adhesions (agn43, fimH, iha), toxins and siderophores (hlyA, iroNE. coli). This diversity in genotypic and phenotypic behavior must be taken into account when making assessments of the suitability of using E. coli as an indicator organism and when modeling the movement of E. coli through the environment.