The role of cell and particle characteristics in the adhesion of E. coli to suspended intertidal sediments

  • Adam James Wyness (Speaker)

Activity: Talk or presentation typesPresentation


Title The role of cell and particle characteristics in the adhesion of E. coli to suspended intertidal sediments. Background The extent of pathogen transport to and within aquatic systems depends heavily on whether the bacterial cells are freely suspended or in association with suspended particles. The surface charge of both bacterial cells and suspended particles affects cell- particle adsorption and subsequent transport and exposure pathways through settling and resuspension cycles. Methods Phenotypic characteristics of 5 E. coli strains were investigated using biofilm formation and swarming assays. The zeta potential (surface charge) of each E. coli strain and 3 physically different types of intertidal sediments was measured over a salinity gradient from 0 – 5 PSU. A batch adsorption microcosm experiment was constructed with each combination of 3 phenotypically different E. coli strains, 3 intertidal sediments and 0, 2, 3.5 and 5 PSU. Results Two types of zeta potential profiles of E. coli strains and sediments were observed; those that had a low negative charge and did not change in response to an increase in salinity, and those that exhibited more negative charge that decreased with an increase in salinity. Strain type was the most important factor in explaining cell-particle adhesion, however adhesion was also dependant on sediment type and salinity (2, 3.5 PSU > 0, 5 PSU). Contrary to previous assertions, zeta potential of strain or sediment did not correlate with cell-particle adhesion. Conclusion E. coli strain characteristics were the most important factor in cell-particle adhesion, implying that diverse strain- specific transport, exposure pathways and system retentions may exist. Further research applying these findings on a catchment scale is necessary to elucidate these pathways.
Period4 Apr 2017
Event titleMicrobiology Society Annual Conference 2017
Event typeConference
LocationEdinburgh, United KingdomShow on map
Degree of RecognitionNational