Combined Poisson and soft-particle DLVO analysis of the specific and nonspecific adhesion forces measured between L. monocytogenes grown at various temperatures and silicon nitride.
Adhesion forces between pathogenic L. monocytogenes EGDe and silicon nitride (Si(3)N(4)) were measured using atomic force microscopy (AFM) under water and at room temperature for cells grown at five different temperatures (10, 20, 30, 37, and 40 °C). Adhesion forces were then decoupled into specific (hydrogen bonding) and nonspecific (electrostatic and Lifshitz-van der Waals) force components using Poisson statistical analysis. The strongest specific and nonspecific attraction forces were observed for cells grown at 30 °C, compared to those observed for cells grown at higher or lower temperatures, respectively. By combining the results of Poisson analysis with the results obtained through soft-particle Derjaguin-Landau-Verwey-Overbeek (DLVO) analysis, the contributions of the Lifshitz-van der Waals and electrostatic forces to the overall nonspecific interaction forces were determined. Our results showed that the Lifshitz-van der Waals attraction forces dominated the total nonspecific adhesion forces for all investigated thermal conditions. However, irrespective of the temperature of growth investigated, hydrogen bonding forces were always stronger than the nonspecific forces. Finally, by combining Poisson analysis with soft-particle analysis of DLVO forces, the closest separation distances where the irreversible bacterial adhesion takes place can be determined relatively easily. For all investigated thermal conditions, the closest separation distances were <1 nm.
Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164-2710, United States.
F Pinar
FP
Gordesli
Nehal I
NI
Abu-Lail
D001422:Bacterial Adhesion; D006801:Humans; D006860:Hydrogen Bonding; D008089:Listeria monocytogenes / Q000737:chemistry / Q000166:cytology*; D008088:Listeriosis / Q000382:microbiology*; D018625:Microscopy, Atomic Force / Q000379:methods; D008954:Models, Biological; D015233:Models, Statistical; D017655:Silicon Compounds / Q000737:chemistry*; D055672:Static Electricity; D013499:Surface Properties; D013696:Temperature
D017655:Silicon Compounds; C032734:silicon nitride