Adhesion mechanics and physical characteristics of Salmonella enteritidis in low moisture environments

Controlling foodborne pathogens in low-moisture environments requires an understanding of how contamination is introduced and spread through a system. Compared with numerous data and studies regarding wet environments, limited information exists concerning the adhesion mechanics of pathogens in low-moisture environments. Therefore, the objectives of this study were to: (1) Develop a framework for adhesion of bacteria in a low moisture environment, (2) perform direct measurements of adhesion mechanics, (3) implement measurements into a model, and (4) validate the model. Physical properties and adhesion characteristics of Salmonella Enteritidis PT30 (SE PT30) attached on stainless steel 304 were assessed by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM), and used to develop a Discrete Element Method (DEM) model as a first principle based approach. This model allowed the estimation of force of reversible adhesion for Salmonella Enteritidis PT30 to be measured as Fad = 3.3459 ± 0.0283 nN. For model validation, a large-scale bacterial detachment experiment utilizing Salmonella was conducted. The modeling results for adhesion was able to elucidate bacterial adhesion mechanics, and the cross-contamination phenomena in low-moisture environment.